need in literature review

Have a language expert improve your writing

Run a free plagiarism check in 10 minutes, generate accurate citations for free.

• Knowledge Base

Methodology

• How to Write a Literature Review | Guide, Examples, & Templates

How to Write a Literature Review | Guide, Examples, & Templates

Published on January 2, 2023 by Shona McCombes . Revised on September 11, 2023.

What is a literature review? A literature review is a survey of scholarly sources on a specific topic. It provides an overview of current knowledge, allowing you to identify relevant theories, methods, and gaps in the existing research that you can later apply to your paper, thesis, or dissertation topic .

There are five key steps to writing a literature review:

• Search for relevant literature
• Evaluate sources
• Identify themes, debates, and gaps
• Outline the structure
• Write your literature review

A good literature review doesn’t just summarize sources—it analyzes, synthesizes , and critically evaluates to give a clear picture of the state of knowledge on the subject.

Instantly correct all language mistakes in your text

Upload your document to correct all your mistakes in minutes

Table of contents

What is the purpose of a literature review, examples of literature reviews, step 1 – search for relevant literature, step 2 – evaluate and select sources, step 3 – identify themes, debates, and gaps, step 4 – outline your literature review’s structure, step 5 – write your literature review, free lecture slides, other interesting articles, frequently asked questions, introduction.

• Quick Run-through
• Step 1 & 2

When you write a thesis , dissertation , or research paper , you will likely have to conduct a literature review to situate your research within existing knowledge. The literature review gives you a chance to:

• Demonstrate your familiarity with the topic and its scholarly context
• Develop a theoretical framework and methodology for your research
• Position your work in relation to other researchers and theorists
• Show how your research addresses a gap or contributes to a debate
• Evaluate the current state of research and demonstrate your knowledge of the scholarly debates around your topic.

Writing literature reviews is a particularly important skill if you want to apply for graduate school or pursue a career in research. We’ve written a step-by-step guide that you can follow below.

Here's why students love Scribbr's proofreading services

Discover proofreading & editing

Writing literature reviews can be quite challenging! A good starting point could be to look at some examples, depending on what kind of literature review you’d like to write.

• Example literature review #1: “Why Do People Migrate? A Review of the Theoretical Literature” ( Theoretical literature review about the development of economic migration theory from the 1950s to today.)
• Example literature review #2: “Literature review as a research methodology: An overview and guidelines” ( Methodological literature review about interdisciplinary knowledge acquisition and production.)
• Example literature review #3: “The Use of Technology in English Language Learning: A Literature Review” ( Thematic literature review about the effects of technology on language acquisition.)
• Example literature review #4: “Learners’ Listening Comprehension Difficulties in English Language Learning: A Literature Review” ( Chronological literature review about how the concept of listening skills has changed over time.)

You can also check out our templates with literature review examples and sample outlines at the links below.

Download Word doc Download Google doc

Before you begin searching for literature, you need a clearly defined topic .

If you are writing the literature review section of a dissertation or research paper, you will search for literature related to your research problem and questions .

Make a list of keywords

Start by creating a list of keywords related to your research question. Include each of the key concepts or variables you’re interested in, and list any synonyms and related terms. You can add to this list as you discover new keywords in the process of your literature search.

• Social media, Facebook, Instagram, Twitter, Snapchat, TikTok
• Body image, self-perception, self-esteem, mental health
• Generation Z, teenagers, adolescents, youth

Search for relevant sources

Use your keywords to begin searching for sources. Some useful databases to search for journals and articles include:

• Your university’s library catalogue
• Google Scholar
• Project Muse (humanities and social sciences)
• Medline (life sciences and biomedicine)
• EconLit (economics)
• Inspec (physics, engineering and computer science)

You can also use boolean operators to help narrow down your search.

Make sure to read the abstract to find out whether an article is relevant to your question. When you find a useful book or article, you can check the bibliography to find other relevant sources.

You likely won’t be able to read absolutely everything that has been written on your topic, so it will be necessary to evaluate which sources are most relevant to your research question.

For each publication, ask yourself:

• What question or problem is the author addressing?
• What are the key concepts and how are they defined?
• What are the key theories, models, and methods?
• Does the research use established frameworks or take an innovative approach?
• What are the results and conclusions of the study?
• How does the publication relate to other literature in the field? Does it confirm, add to, or challenge established knowledge?
• What are the strengths and weaknesses of the research?

Make sure the sources you use are credible , and make sure you read any landmark studies and major theories in your field of research.

You can use our template to summarize and evaluate sources you’re thinking about using. Click on either button below to download.

Take notes and cite your sources

As you read, you should also begin the writing process. Take notes that you can later incorporate into the text of your literature review.

It is important to keep track of your sources with citations to avoid plagiarism . It can be helpful to make an annotated bibliography , where you compile full citation information and write a paragraph of summary and analysis for each source. This helps you remember what you read and saves time later in the process.

The only proofreading tool specialized in correcting academic writing - try for free!

The academic proofreading tool has been trained on 1000s of academic texts and by native English editors. Making it the most accurate and reliable proofreading tool for students.

Try for free

To begin organizing your literature review’s argument and structure, be sure you understand the connections and relationships between the sources you’ve read. Based on your reading and notes, you can look for:

• Trends and patterns (in theory, method or results): do certain approaches become more or less popular over time?
• Themes: what questions or concepts recur across the literature?
• Debates, conflicts and contradictions: where do sources disagree?
• Pivotal publications: are there any influential theories or studies that changed the direction of the field?
• Gaps: what is missing from the literature? Are there weaknesses that need to be addressed?

This step will help you work out the structure of your literature review and (if applicable) show how your own research will contribute to existing knowledge.

• Most research has focused on young women.
• There is an increasing interest in the visual aspects of social media.
• But there is still a lack of robust research on highly visual platforms like Instagram and Snapchat—this is a gap that you could address in your own research.

There are various approaches to organizing the body of a literature review. Depending on the length of your literature review, you can combine several of these strategies (for example, your overall structure might be thematic, but each theme is discussed chronologically).

Chronological

The simplest approach is to trace the development of the topic over time. However, if you choose this strategy, be careful to avoid simply listing and summarizing sources in order.

Try to analyze patterns, turning points and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred.

If you have found some recurring central themes, you can organize your literature review into subsections that address different aspects of the topic.

For example, if you are reviewing literature about inequalities in migrant health outcomes, key themes might include healthcare policy, language barriers, cultural attitudes, legal status, and economic access.

Methodological

If you draw your sources from different disciplines or fields that use a variety of research methods , you might want to compare the results and conclusions that emerge from different approaches. For example:

• Look at what results have emerged in qualitative versus quantitative research
• Discuss how the topic has been approached by empirical versus theoretical scholarship
• Divide the literature into sociological, historical, and cultural sources

Theoretical

A literature review is often the foundation for a theoretical framework . You can use it to discuss various theories, models, and definitions of key concepts.

You might argue for the relevance of a specific theoretical approach, or combine various theoretical concepts to create a framework for your research.

Like any other academic text , your literature review should have an introduction , a main body, and a conclusion . What you include in each depends on the objective of your literature review.

The introduction should clearly establish the focus and purpose of the literature review.

Depending on the length of your literature review, you might want to divide the body into subsections. You can use a subheading for each theme, time period, or methodological approach.

As you write, you can follow these tips:

• Summarize and synthesize: give an overview of the main points of each source and combine them into a coherent whole
• Analyze and interpret: don’t just paraphrase other researchers — add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
• Critically evaluate: mention the strengths and weaknesses of your sources
• Write in well-structured paragraphs: use transition words and topic sentences to draw connections, comparisons and contrasts

In the conclusion, you should summarize the key findings you have taken from the literature and emphasize their significance.

When you’ve finished writing and revising your literature review, don’t forget to proofread thoroughly before submitting. Not a language expert? Check out Scribbr’s professional proofreading services !

This article has been adapted into lecture slides that you can use to teach your students about writing a literature review.

Scribbr slides are free to use, customize, and distribute for educational purposes.

Open Google Slides Download PowerPoint

If you want to know more about the research process , methodology , research bias , or statistics , make sure to check out some of our other articles with explanations and examples.

• Sampling methods
• Simple random sampling
• Stratified sampling
• Cluster sampling
• Likert scales
• Reproducibility

 Statistics

• Null hypothesis
• Statistical power
• Probability distribution
• Effect size
• Poisson distribution

Research bias

• Optimism bias
• Cognitive bias
• Implicit bias
• Hawthorne effect
• Anchoring bias
• Explicit bias

A literature review is a survey of scholarly sources (such as books, journal articles, and theses) related to a specific topic or research question .

It is often written as part of a thesis, dissertation , or research paper , in order to situate your work in relation to existing knowledge.

There are several reasons to conduct a literature review at the beginning of a research project:

• To familiarize yourself with the current state of knowledge on your topic
• To ensure that you’re not just repeating what others have already done
• To identify gaps in knowledge and unresolved problems that your research can address
• To develop your theoretical framework and methodology
• To provide an overview of the key findings and debates on the topic

Writing the literature review shows your reader how your work relates to existing research and what new insights it will contribute.

The literature review usually comes near the beginning of your thesis or dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .

A literature review is a survey of credible sources on a topic, often used in dissertations , theses, and research papers . Literature reviews give an overview of knowledge on a subject, helping you identify relevant theories and methods, as well as gaps in existing research. Literature reviews are set up similarly to other  academic texts , with an introduction , a main body, and a conclusion .

An  annotated bibliography is a list of  source references that has a short description (called an annotation ) for each of the sources. It is often assigned as part of the research process for a  paper .  

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.

McCombes, S. (2023, September 11). How to Write a Literature Review | Guide, Examples, & Templates. Scribbr. Retrieved April 9, 2024, from https://www.scribbr.com/dissertation/literature-review/

Is this article helpful?

Shona McCombes

Other students also liked, what is a theoretical framework | guide to organizing, what is a research methodology | steps & tips, how to write a research proposal | examples & templates, unlimited academic ai-proofreading.

✔ Document error-free in 5minutes ✔ Unlimited document corrections ✔ Specialized in correcting academic texts

Purdue Online Writing Lab Purdue OWL® College of Liberal Arts

Writing a Literature Review

Welcome to the Purdue OWL

This page is brought to you by the OWL at Purdue University. When printing this page, you must include the entire legal notice.

Copyright ©1995-2018 by The Writing Lab & The OWL at Purdue and Purdue University. All rights reserved. This material may not be published, reproduced, broadcast, rewritten, or redistributed without permission. Use of this site constitutes acceptance of our terms and conditions of fair use.

A literature review is a document or section of a document that collects key sources on a topic and discusses those sources in conversation with each other (also called synthesis ). The lit review is an important genre in many disciplines, not just literature (i.e., the study of works of literature such as novels and plays). When we say “literature review” or refer to “the literature,” we are talking about the research ( scholarship ) in a given field. You will often see the terms “the research,” “the scholarship,” and “the literature” used mostly interchangeably.

Where, when, and why would I write a lit review?

There are a number of different situations where you might write a literature review, each with slightly different expectations; different disciplines, too, have field-specific expectations for what a literature review is and does. For instance, in the humanities, authors might include more overt argumentation and interpretation of source material in their literature reviews, whereas in the sciences, authors are more likely to report study designs and results in their literature reviews; these differences reflect these disciplines’ purposes and conventions in scholarship. You should always look at examples from your own discipline and talk to professors or mentors in your field to be sure you understand your discipline’s conventions, for literature reviews as well as for any other genre.

A literature review can be a part of a research paper or scholarly article, usually falling after the introduction and before the research methods sections. In these cases, the lit review just needs to cover scholarship that is important to the issue you are writing about; sometimes it will also cover key sources that informed your research methodology.

Lit reviews can also be standalone pieces, either as assignments in a class or as publications. In a class, a lit review may be assigned to help students familiarize themselves with a topic and with scholarship in their field, get an idea of the other researchers working on the topic they’re interested in, find gaps in existing research in order to propose new projects, and/or develop a theoretical framework and methodology for later research. As a publication, a lit review usually is meant to help make other scholars’ lives easier by collecting and summarizing, synthesizing, and analyzing existing research on a topic. This can be especially helpful for students or scholars getting into a new research area, or for directing an entire community of scholars toward questions that have not yet been answered.

What are the parts of a lit review?

Most lit reviews use a basic introduction-body-conclusion structure; if your lit review is part of a larger paper, the introduction and conclusion pieces may be just a few sentences while you focus most of your attention on the body. If your lit review is a standalone piece, the introduction and conclusion take up more space and give you a place to discuss your goals, research methods, and conclusions separately from where you discuss the literature itself.

Introduction:

• An introductory paragraph that explains what your working topic and thesis is
• A forecast of key topics or texts that will appear in the review
• Potentially, a description of how you found sources and how you analyzed them for inclusion and discussion in the review (more often found in published, standalone literature reviews than in lit review sections in an article or research paper)
• Summarize and synthesize: Give an overview of the main points of each source and combine them into a coherent whole
• Analyze and interpret: Don’t just paraphrase other researchers – add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
• Critically Evaluate: Mention the strengths and weaknesses of your sources
• Write in well-structured paragraphs: Use transition words and topic sentence to draw connections, comparisons, and contrasts.

Conclusion:

• Summarize the key findings you have taken from the literature and emphasize their significance
• Connect it back to your primary research question

How should I organize my lit review?

Lit reviews can take many different organizational patterns depending on what you are trying to accomplish with the review. Here are some examples:

• Chronological : The simplest approach is to trace the development of the topic over time, which helps familiarize the audience with the topic (for instance if you are introducing something that is not commonly known in your field). If you choose this strategy, be careful to avoid simply listing and summarizing sources in order. Try to analyze the patterns, turning points, and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred (as mentioned previously, this may not be appropriate in your discipline — check with a teacher or mentor if you’re unsure).
• Thematic : If you have found some recurring central themes that you will continue working with throughout your piece, you can organize your literature review into subsections that address different aspects of the topic. For example, if you are reviewing literature about women and religion, key themes can include the role of women in churches and the religious attitude towards women.
• Qualitative versus quantitative research
• Empirical versus theoretical scholarship
• Divide the research by sociological, historical, or cultural sources
• Theoretical : In many humanities articles, the literature review is the foundation for the theoretical framework. You can use it to discuss various theories, models, and definitions of key concepts. You can argue for the relevance of a specific theoretical approach or combine various theorical concepts to create a framework for your research.

What are some strategies or tips I can use while writing my lit review?

Any lit review is only as good as the research it discusses; make sure your sources are well-chosen and your research is thorough. Don’t be afraid to do more research if you discover a new thread as you’re writing. More info on the research process is available in our "Conducting Research" resources .

As you’re doing your research, create an annotated bibliography ( see our page on the this type of document ). Much of the information used in an annotated bibliography can be used also in a literature review, so you’ll be not only partially drafting your lit review as you research, but also developing your sense of the larger conversation going on among scholars, professionals, and any other stakeholders in your topic.

Usually you will need to synthesize research rather than just summarizing it. This means drawing connections between sources to create a picture of the scholarly conversation on a topic over time. Many student writers struggle to synthesize because they feel they don’t have anything to add to the scholars they are citing; here are some strategies to help you:

• It often helps to remember that the point of these kinds of syntheses is to show your readers how you understand your research, to help them read the rest of your paper.
• Writing teachers often say synthesis is like hosting a dinner party: imagine all your sources are together in a room, discussing your topic. What are they saying to each other?
• Look at the in-text citations in each paragraph. Are you citing just one source for each paragraph? This usually indicates summary only. When you have multiple sources cited in a paragraph, you are more likely to be synthesizing them (not always, but often
• Read more about synthesis here.

The most interesting literature reviews are often written as arguments (again, as mentioned at the beginning of the page, this is discipline-specific and doesn’t work for all situations). Often, the literature review is where you can establish your research as filling a particular gap or as relevant in a particular way. You have some chance to do this in your introduction in an article, but the literature review section gives a more extended opportunity to establish the conversation in the way you would like your readers to see it. You can choose the intellectual lineage you would like to be part of and whose definitions matter most to your thinking (mostly humanities-specific, but this goes for sciences as well). In addressing these points, you argue for your place in the conversation, which tends to make the lit review more compelling than a simple reporting of other sources.

Get science-backed answers as you write with Paperpal's Research feature

What is a Literature Review? How to Write It (with Examples)

A literature review is a critical analysis and synthesis of existing research on a particular topic. It provides an overview of the current state of knowledge, identifies gaps, and highlights key findings in the literature. 1 The purpose of a literature review is to situate your own research within the context of existing scholarship, demonstrating your understanding of the topic and showing how your work contributes to the ongoing conversation in the field. Learning how to write a literature review is a critical tool for successful research. Your ability to summarize and synthesize prior research pertaining to a certain topic demonstrates your grasp on the topic of study, and assists in the learning process. 

Table of Contents

• What is the purpose of literature review? 
• a. Habitat Loss and Species Extinction: 
• b. Range Shifts and Phenological Changes: 
• c. Ocean Acidification and Coral Reefs: 
• d. Adaptive Strategies and Conservation Efforts: 
• How to write a good literature review 
• Choose a Topic and Define the Research Question: 
• Decide on the Scope of Your Review: 
• Select Databases for Searches: 
• Conduct Searches and Keep Track: 
• Review the Literature: 
• Organize and Write Your Literature Review: 
• Frequently asked questions 

What is a literature review?

A well-conducted literature review demonstrates the researcher’s familiarity with the existing literature, establishes the context for their own research, and contributes to scholarly conversations on the topic. One of the purposes of a literature review is also to help researchers avoid duplicating previous work and ensure that their research is informed by and builds upon the existing body of knowledge.

What is the purpose of literature review?

A literature review serves several important purposes within academic and research contexts. Here are some key objectives and functions of a literature review: 2  

• Contextualizing the Research Problem: The literature review provides a background and context for the research problem under investigation. It helps to situate the study within the existing body of knowledge. 
• Identifying Gaps in Knowledge: By identifying gaps, contradictions, or areas requiring further research, the researcher can shape the research question and justify the significance of the study. This is crucial for ensuring that the new research contributes something novel to the field. 
• Understanding Theoretical and Conceptual Frameworks: Literature reviews help researchers gain an understanding of the theoretical and conceptual frameworks used in previous studies. This aids in the development of a theoretical framework for the current research. 
• Providing Methodological Insights: Another purpose of literature reviews is that it allows researchers to learn about the methodologies employed in previous studies. This can help in choosing appropriate research methods for the current study and avoiding pitfalls that others may have encountered. 
• Establishing Credibility: A well-conducted literature review demonstrates the researcher’s familiarity with existing scholarship, establishing their credibility and expertise in the field. It also helps in building a solid foundation for the new research. 
• Informing Hypotheses or Research Questions: The literature review guides the formulation of hypotheses or research questions by highlighting relevant findings and areas of uncertainty in existing literature. 

Literature review example

Let’s delve deeper with a literature review example: Let’s say your literature review is about the impact of climate change on biodiversity. You might format your literature review into sections such as the effects of climate change on habitat loss and species extinction, phenological changes, and marine biodiversity. Each section would then summarize and analyze relevant studies in those areas, highlighting key findings and identifying gaps in the research. The review would conclude by emphasizing the need for further research on specific aspects of the relationship between climate change and biodiversity. The following literature review template provides a glimpse into the recommended literature review structure and content, demonstrating how research findings are organized around specific themes within a broader topic. 

Literature Review on Climate Change Impacts on Biodiversity:

Climate change is a global phenomenon with far-reaching consequences, including significant impacts on biodiversity. This literature review synthesizes key findings from various studies: 

a. Habitat Loss and Species Extinction:

Climate change-induced alterations in temperature and precipitation patterns contribute to habitat loss, affecting numerous species (Thomas et al., 2004). The review discusses how these changes increase the risk of extinction, particularly for species with specific habitat requirements. 

b. Range Shifts and Phenological Changes:

Observations of range shifts and changes in the timing of biological events (phenology) are documented in response to changing climatic conditions (Parmesan & Yohe, 2003). These shifts affect ecosystems and may lead to mismatches between species and their resources. 

c. Ocean Acidification and Coral Reefs:

The review explores the impact of climate change on marine biodiversity, emphasizing ocean acidification’s threat to coral reefs (Hoegh-Guldberg et al., 2007). Changes in pH levels negatively affect coral calcification, disrupting the delicate balance of marine ecosystems. 

d. Adaptive Strategies and Conservation Efforts:

Recognizing the urgency of the situation, the literature review discusses various adaptive strategies adopted by species and conservation efforts aimed at mitigating the impacts of climate change on biodiversity (Hannah et al., 2007). It emphasizes the importance of interdisciplinary approaches for effective conservation planning. 

How to write a good literature review

Writing a literature review involves summarizing and synthesizing existing research on a particular topic. A good literature review format should include the following elements. 

Introduction: The introduction sets the stage for your literature review, providing context and introducing the main focus of your review. 

• Opening Statement: Begin with a general statement about the broader topic and its significance in the field. 
• Scope and Purpose: Clearly define the scope of your literature review. Explain the specific research question or objective you aim to address. 
• Organizational Framework: Briefly outline the structure of your literature review, indicating how you will categorize and discuss the existing research. 
• Significance of the Study: Highlight why your literature review is important and how it contributes to the understanding of the chosen topic. 
• Thesis Statement: Conclude the introduction with a concise thesis statement that outlines the main argument or perspective you will develop in the body of the literature review. 

Body: The body of the literature review is where you provide a comprehensive analysis of existing literature, grouping studies based on themes, methodologies, or other relevant criteria. 

• Organize by Theme or Concept: Group studies that share common themes, concepts, or methodologies. Discuss each theme or concept in detail, summarizing key findings and identifying gaps or areas of disagreement. 
• Critical Analysis: Evaluate the strengths and weaknesses of each study. Discuss the methodologies used, the quality of evidence, and the overall contribution of each work to the understanding of the topic. 
• Synthesis of Findings: Synthesize the information from different studies to highlight trends, patterns, or areas of consensus in the literature. 
• Identification of Gaps: Discuss any gaps or limitations in the existing research and explain how your review contributes to filling these gaps. 
• Transition between Sections: Provide smooth transitions between different themes or concepts to maintain the flow of your literature review. 

Conclusion: The conclusion of your literature review should summarize the main findings, highlight the contributions of the review, and suggest avenues for future research. 

• Summary of Key Findings: Recap the main findings from the literature and restate how they contribute to your research question or objective. 
• Contributions to the Field: Discuss the overall contribution of your literature review to the existing knowledge in the field. 
• Implications and Applications: Explore the practical implications of the findings and suggest how they might impact future research or practice. 
• Recommendations for Future Research: Identify areas that require further investigation and propose potential directions for future research in the field. 
• Final Thoughts: Conclude with a final reflection on the importance of your literature review and its relevance to the broader academic community. 

Conducting a literature review

Conducting a literature review is an essential step in research that involves reviewing and analyzing existing literature on a specific topic. It’s important to know how to do a literature review effectively, so here are the steps to follow: 1  

Choose a Topic and Define the Research Question:

• Select a topic that is relevant to your field of study. 
• Clearly define your research question or objective. Determine what specific aspect of the topic do you want to explore? 

Decide on the Scope of Your Review:

• Determine the timeframe for your literature review. Are you focusing on recent developments, or do you want a historical overview? 
• Consider the geographical scope. Is your review global, or are you focusing on a specific region? 
• Define the inclusion and exclusion criteria. What types of sources will you include? Are there specific types of studies or publications you will exclude? 

Select Databases for Searches:

• Identify relevant databases for your field. Examples include PubMed, IEEE Xplore, Scopus, Web of Science, and Google Scholar. 
• Consider searching in library catalogs, institutional repositories, and specialized databases related to your topic. 

Conduct Searches and Keep Track:

• Develop a systematic search strategy using keywords, Boolean operators (AND, OR, NOT), and other search techniques. 
• Record and document your search strategy for transparency and replicability. 
• Keep track of the articles, including publication details, abstracts, and links. Use citation management tools like EndNote, Zotero, or Mendeley to organize your references. 

Review the Literature:

• Evaluate the relevance and quality of each source. Consider the methodology, sample size, and results of studies. 
• Organize the literature by themes or key concepts. Identify patterns, trends, and gaps in the existing research. 
• Summarize key findings and arguments from each source. Compare and contrast different perspectives. 
• Identify areas where there is a consensus in the literature and where there are conflicting opinions. 
• Provide critical analysis and synthesis of the literature. What are the strengths and weaknesses of existing research? 

Organize and Write Your Literature Review:

• Literature review outline should be based on themes, chronological order, or methodological approaches. 
• Write a clear and coherent narrative that synthesizes the information gathered. 
• Use proper citations for each source and ensure consistency in your citation style (APA, MLA, Chicago, etc.). 
• Conclude your literature review by summarizing key findings, identifying gaps, and suggesting areas for future research. 

The literature review sample and detailed advice on writing and conducting a review will help you produce a well-structured report. But remember that a literature review is an ongoing process, and it may be necessary to revisit and update it as your research progresses. 

Frequently asked questions

A literature review is a critical and comprehensive analysis of existing literature (published and unpublished works) on a specific topic or research question and provides a synthesis of the current state of knowledge in a particular field. A well-conducted literature review is crucial for researchers to build upon existing knowledge, avoid duplication of efforts, and contribute to the advancement of their field. It also helps researchers situate their work within a broader context and facilitates the development of a sound theoretical and conceptual framework for their studies.

Literature review is a crucial component of research writing, providing a solid background for a research paper’s investigation. The aim is to keep professionals up to date by providing an understanding of ongoing developments within a specific field, including research methods, and experimental techniques used in that field, and present that knowledge in the form of a written report. Also, the depth and breadth of the literature review emphasizes the credibility of the scholar in his or her field.  

Before writing a literature review, it’s essential to undertake several preparatory steps to ensure that your review is well-researched, organized, and focused. This includes choosing a topic of general interest to you and doing exploratory research on that topic, writing an annotated bibliography, and noting major points, especially those that relate to the position you have taken on the topic. 

Literature reviews and academic research papers are essential components of scholarly work but serve different purposes within the academic realm. 3 A literature review aims to provide a foundation for understanding the current state of research on a particular topic, identify gaps or controversies, and lay the groundwork for future research. Therefore, it draws heavily from existing academic sources, including books, journal articles, and other scholarly publications. In contrast, an academic research paper aims to present new knowledge, contribute to the academic discourse, and advance the understanding of a specific research question. Therefore, it involves a mix of existing literature (in the introduction and literature review sections) and original data or findings obtained through research methods. 

Literature reviews are essential components of academic and research papers, and various strategies can be employed to conduct them effectively. If you want to know how to write a literature review for a research paper, here are four common approaches that are often used by researchers.  Chronological Review: This strategy involves organizing the literature based on the chronological order of publication. It helps to trace the development of a topic over time, showing how ideas, theories, and research have evolved.  Thematic Review: Thematic reviews focus on identifying and analyzing themes or topics that cut across different studies. Instead of organizing the literature chronologically, it is grouped by key themes or concepts, allowing for a comprehensive exploration of various aspects of the topic.  Methodological Review: This strategy involves organizing the literature based on the research methods employed in different studies. It helps to highlight the strengths and weaknesses of various methodologies and allows the reader to evaluate the reliability and validity of the research findings.  Theoretical Review: A theoretical review examines the literature based on the theoretical frameworks used in different studies. This approach helps to identify the key theories that have been applied to the topic and assess their contributions to the understanding of the subject.  It’s important to note that these strategies are not mutually exclusive, and a literature review may combine elements of more than one approach. The choice of strategy depends on the research question, the nature of the literature available, and the goals of the review. Additionally, other strategies, such as integrative reviews or systematic reviews, may be employed depending on the specific requirements of the research.

The literature review format can vary depending on the specific publication guidelines. However, there are some common elements and structures that are often followed. Here is a general guideline for the format of a literature review:  Introduction:   Provide an overview of the topic.  Define the scope and purpose of the literature review.  State the research question or objective.  Body:   Organize the literature by themes, concepts, or chronology.  Critically analyze and evaluate each source.  Discuss the strengths and weaknesses of the studies.  Highlight any methodological limitations or biases.  Identify patterns, connections, or contradictions in the existing research.  Conclusion:   Summarize the key points discussed in the literature review.  Highlight the research gap.  Address the research question or objective stated in the introduction.  Highlight the contributions of the review and suggest directions for future research.

Both annotated bibliographies and literature reviews involve the examination of scholarly sources. While annotated bibliographies focus on individual sources with brief annotations, literature reviews provide a more in-depth, integrated, and comprehensive analysis of existing literature on a specific topic. The key differences are as follows: 

References 

• Denney, A. S., & Tewksbury, R. (2013). How to write a literature review.  Journal of criminal justice education ,  24 (2), 218-234. 
• Pan, M. L. (2016).  Preparing literature reviews: Qualitative and quantitative approaches . Taylor & Francis. 
• Cantero, C. (2019). How to write a literature review.  San José State University Writing Center . 

Paperpal is an AI writing assistant that help academics write better, faster with real-time suggestions for in-depth language and grammar correction. Trained on millions of research manuscripts enhanced by professional academic editors, Paperpal delivers human precision at machine speed.  

Try it for free or upgrade to  Paperpal Prime , which unlocks unlimited access to premium features like academic translation, paraphrasing, contextual synonyms, consistency checks and more. It’s like always having a professional academic editor by your side! Go beyond limitations and experience the future of academic writing.  Get Paperpal Prime now at just US$19 a month!

Related Reads:

• Empirical Research: A Comprehensive Guide for Academics 
• How to Write a Scientific Paper in 10 Steps 
• Life Sciences Papers: 9 Tips for Authors Writing in Biological Sciences
• What is an Argumentative Essay? How to Write It (With Examples)

6 Tips for Post-Doc Researchers to Take Their Career to the Next Level

Self-plagiarism in research: what it is and how to avoid it, you may also like, what is hedging in academic writing  , how to use ai to enhance your college..., ai + human expertise – a paradigm shift..., how to use paperpal to generate emails &..., ai in education: it’s time to change the..., is it ethical to use ai-generated abstracts without..., do plagiarism checkers detect ai content, word choice problems: how to use the right..., how to avoid plagiarism when using generative ai..., what are journal guidelines on using generative ai....

• Resources Home 🏠
• Try SciSpace Copilot
• Search research papers
• Add Copilot Extension
• Try AI Detector
• Try Paraphraser
• Try Citation Generator
• April Papers
• June Papers
• July Papers

How To Write A Literature Review - A Complete Guide

Table of Contents

A literature review is much more than just another section in your research paper. It forms the very foundation of your research. It is a formal piece of writing where you analyze the existing theoretical framework, principles, and assumptions and use that as a base to shape your approach to the research question.

Curating and drafting a solid literature review section not only lends more credibility to your research paper but also makes your research tighter and better focused. But, writing literature reviews is a difficult task. It requires extensive reading, plus you have to consider market trends and technological and political changes, which tend to change in the blink of an eye.

Now streamline your literature review process with the help of SciSpace Copilot. With this AI research assistant, you can efficiently synthesize and analyze a vast amount of information, identify key themes and trends, and uncover gaps in the existing research. Get real-time explanations, summaries, and answers to your questions for the paper you're reviewing, making navigating and understanding the complex literature landscape easier.

In this comprehensive guide, we will explore everything from the definition of a literature review, its appropriate length, various types of literature reviews, and how to write one.

What is a literature review?

A literature review is a collation of survey, research, critical evaluation, and assessment of the existing literature in a preferred domain.

Eminent researcher and academic Arlene Fink, in her book Conducting Research Literature Reviews , defines it as the following:

“A literature review surveys books, scholarly articles, and any other sources relevant to a particular issue, area of research, or theory, and by so doing, provides a description, summary, and critical evaluation of these works in relation to the research problem being investigated.

Literature reviews are designed to provide an overview of sources you have explored while researching a particular topic, and to demonstrate to your readers how your research fits within a larger field of study.”

Simply put, a literature review can be defined as a critical discussion of relevant pre-existing research around your research question and carving out a definitive place for your study in the existing body of knowledge. Literature reviews can be presented in multiple ways: a section of an article, the whole research paper itself, or a chapter of your thesis.

A literature review does function as a summary of sources, but it also allows you to analyze further, interpret, and examine the stated theories, methods, viewpoints, and, of course, the gaps in the existing content.

As an author, you can discuss and interpret the research question and its various aspects and debate your adopted methods to support the claim.

What is the purpose of a literature review?

A literature review is meant to help your readers understand the relevance of your research question and where it fits within the existing body of knowledge. As a researcher, you should use it to set the context, build your argument, and establish the need for your study.

What is the importance of a literature review?

The literature review is a critical part of research papers because it helps you:

• Gain an in-depth understanding of your research question and the surrounding area
• Convey that you have a thorough understanding of your research area and are up-to-date with the latest changes and advancements
• Establish how your research is connected or builds on the existing body of knowledge and how it could contribute to further research
• Elaborate on the validity and suitability of your theoretical framework and research methodology
• Identify and highlight gaps and shortcomings in the existing body of knowledge and how things need to change
• Convey to readers how your study is different or how it contributes to the research area

How long should a literature review be?

Ideally, the literature review should take up 15%-40% of the total length of your manuscript. So, if you have a 10,000-word research paper, the minimum word count could be 1500.

Your literature review format depends heavily on the kind of manuscript you are writing — an entire chapter in case of doctoral theses, a part of the introductory section in a research article, to a full-fledged review article that examines the previously published research on a topic.

Another determining factor is the type of research you are doing. The literature review section tends to be longer for secondary research projects than primary research projects.

What are the different types of literature reviews?

All literature reviews are not the same. There are a variety of possible approaches that you can take. It all depends on the type of research you are pursuing.

Here are the different types of literature reviews:

Argumentative review

It is called an argumentative review when you carefully present literature that only supports or counters a specific argument or premise to establish a viewpoint.

Integrative review

It is a type of literature review focused on building a comprehensive understanding of a topic by combining available theoretical frameworks and empirical evidence.

Methodological review

This approach delves into the ''how'' and the ''what" of the research question —  you cannot look at the outcome in isolation; you should also review the methodology used.

Systematic review

This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research and collect, report, and analyze data from the studies included in the review.

Meta-analysis review

Meta-analysis uses statistical methods to summarize the results of independent studies. By combining information from all relevant studies, meta-analysis can provide more precise estimates of the effects than those derived from the individual studies included within a review.

Historical review

Historical literature reviews focus on examining research throughout a period, often starting with the first time an issue, concept, theory, or phenomenon emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and identify future research's likely directions.

Theoretical Review

This form aims to examine the corpus of theory accumulated regarding an issue, concept, theory, and phenomenon. The theoretical literature review helps to establish what theories exist, the relationships between them, the degree the existing approaches have been investigated, and to develop new hypotheses to be tested.

Scoping Review

The Scoping Review is often used at the beginning of an article, dissertation, or research proposal. It is conducted before the research to highlight gaps in the existing body of knowledge and explains why the project should be greenlit.

State-of-the-Art Review

The State-of-the-Art review is conducted periodically, focusing on the most recent research. It describes what is currently known, understood, or agreed upon regarding the research topic and highlights where there are still disagreements.

Can you use the first person in a literature review?

When writing literature reviews, you should avoid the usage of first-person pronouns. It means that instead of "I argue that" or "we argue that," the appropriate expression would be "this research paper argues that."

Do you need an abstract for a literature review?

Ideally, yes. It is always good to have a condensed summary that is self-contained and independent of the rest of your review. As for how to draft one, you can follow the same fundamental idea when preparing an abstract for a literature review. It should also include:

• The research topic and your motivation behind selecting it
• A one-sentence thesis statement
• An explanation of the kinds of literature featured in the review
• Summary of what you've learned
• Conclusions you drew from the literature you reviewed
• Potential implications and future scope for research

Here's an example of the abstract of a literature review

Is a literature review written in the past tense?

Yes, the literature review should ideally be written in the past tense. You should not use the present or future tense when writing one. The exceptions are when you have statements describing events that happened earlier than the literature you are reviewing or events that are currently occurring; then, you can use the past perfect or present perfect tenses.

How many sources for a literature review?

There are multiple approaches to deciding how many sources to include in a literature review section. The first approach would be to look level you are at as a researcher. For instance, a doctoral thesis might need 60+ sources. In contrast, you might only need to refer to 5-15 sources at the undergraduate level.

The second approach is based on the kind of literature review you are doing — whether it is merely a chapter of your paper or if it is a self-contained paper in itself. When it is just a chapter, sources should equal the total number of pages in your article's body. In the second scenario, you need at least three times as many sources as there are pages in your work.

Quick tips on how to write a literature review

To know how to write a literature review, you must clearly understand its impact and role in establishing your work as substantive research material.

You need to follow the below-mentioned steps, to write a literature review:

• Outline the purpose behind the literature review
• Search relevant literature
• Examine and assess the relevant resources
• Discover connections by drawing deep insights from the resources
• Structure planning to write a good literature review

1. Outline and identify the purpose of  a literature review

As a first step on how to write a literature review, you must know what the research question or topic is and what shape you want your literature review to take. Ensure you understand the research topic inside out, or else seek clarifications. You must be able to the answer below questions before you start:

• How many sources do I need to include?
• What kind of sources should I analyze?
• How much should I critically evaluate each source?
• Should I summarize, synthesize or offer a critique of the sources?
• Do I need to include any background information or definitions?

Additionally, you should know that the narrower your research topic is, the swifter it will be for you to restrict the number of sources to be analyzed.

2. Search relevant literature

Dig deeper into search engines to discover what has already been published around your chosen topic. Make sure you thoroughly go through appropriate reference sources like books, reports, journal articles, government docs, and web-based resources.

You must prepare a list of keywords and their different variations. You can start your search from any library’s catalog, provided you are an active member of that institution. The exact keywords can be extended to widen your research over other databases and academic search engines like:

• Google Scholar
• Microsoft Academic
• Science.gov

Besides, it is not advisable to go through every resource word by word. Alternatively, what you can do is you can start by reading the abstract and then decide whether that source is relevant to your research or not.

Additionally, you must spend surplus time assessing the quality and relevance of resources. It would help if you tried preparing a list of citations to ensure that there lies no repetition of authors, publications, or articles in the literature review.

3. Examine and assess the sources

It is nearly impossible for you to go through every detail in the research article. So rather than trying to fetch every detail, you have to analyze and decide which research sources resemble closest and appear relevant to your chosen domain.

While analyzing the sources, you should look to find out answers to questions like:

• What question or problem has the author been describing and debating?
• What is the definition of critical aspects?
• How well the theories, approach, and methodology have been explained?
• Whether the research theory used some conventional or new innovative approach?
• How relevant are the key findings of the work?
• In what ways does it relate to other sources on the same topic?
• What challenges does this research paper pose to the existing theory
• What are the possible contributions or benefits it adds to the subject domain?

Be always mindful that you refer only to credible and authentic resources. It would be best if you always take references from different publications to validate your theory.

Always keep track of important information or data you can present in your literature review right from the beginning. It will help steer your path from any threats of plagiarism and also make it easier to curate an annotated bibliography or reference section.

4. Discover connections

At this stage, you must start deciding on the argument and structure of your literature review. To accomplish this, you must discover and identify the relations and connections between various resources while drafting your abstract.

A few aspects that you should be aware of while writing a literature review include:

• Rise to prominence: Theories and methods that have gained reputation and supporters over time.
• Constant scrutiny: Concepts or theories that repeatedly went under examination.
• Contradictions and conflicts: Theories, both the supporting and the contradictory ones, for the research topic.
• Knowledge gaps: What exactly does it fail to address, and how to bridge them with further research?
• Influential resources: Significant research projects available that have been upheld as milestones or perhaps, something that can modify the current trends

Once you join the dots between various past research works, it will be easier for you to draw a conclusion and identify your contribution to the existing knowledge base.

5. Structure planning to write a good literature review

There exist different ways towards planning and executing the structure of a literature review. The format of a literature review varies and depends upon the length of the research.

Like any other research paper, the literature review format must contain three sections: introduction, body, and conclusion. The goals and objectives of the research question determine what goes inside these three sections.

Nevertheless, a good literature review can be structured according to the chronological, thematic, methodological, or theoretical framework approach.

Literature review samples

1. Standalone

2. As a section of a research paper

How SciSpace Discover makes literature review a breeze?

SciSpace Discover is a one-stop solution to do an effective literature search and get barrier-free access to scientific knowledge. It is an excellent repository where you can find millions of only peer-reviewed articles and full-text PDF files. Here’s more on how you can use it:

Find the right information

Find what you want quickly and easily with comprehensive search filters that let you narrow down papers according to PDF availability, year of publishing, document type, and affiliated institution. Moreover, you can sort the results based on the publishing date, citation count, and relevance.

Assess credibility of papers quickly

When doing the literature review, it is critical to establish the quality of your sources. They form the foundation of your research. SciSpace Discover helps you assess the quality of a source by providing an overview of its references, citations, and performance metrics.

Get the complete picture in no time

SciSpace Discover’s personalized suggestion engine helps you stay on course and get the complete picture of the topic from one place. Every time you visit an article page, it provides you links to related papers. Besides that, it helps you understand what’s trending, who are the top authors, and who are the leading publishers on a topic.

Make referring sources super easy

To ensure you don't lose track of your sources, you must start noting down your references when doing the literature review. SciSpace Discover makes this step effortless. Click the 'cite' button on an article page, and you will receive preloaded citation text in multiple styles — all you've to do is copy-paste it into your manuscript.

Final tips on how to write a literature review

A massive chunk of time and effort is required to write a good literature review. But, if you go about it systematically, you'll be able to save a ton of time and build a solid foundation for your research.

We hope this guide has helped you answer several key questions you have about writing literature reviews.

Would you like to explore SciSpace Discover and kick off your literature search right away? You can get started here .

Frequently Asked Questions (FAQs)

1. how to start a literature review.

• What questions do you want to answer?

• What sources do you need to answer these questions?

• What information do these sources contain?

• How can you use this information to answer your questions?

2. What to include in a literature review?

• A brief background of the problem or issue

• What has previously been done to address the problem or issue

• A description of what you will do in your project

• How this study will contribute to research on the subject

3. Why literature review is important?

The literature review is an important part of any research project because it allows the writer to look at previous studies on a topic and determine existing gaps in the literature, as well as what has already been done. It will also help them to choose the most appropriate method for their own study.

4. How to cite a literature review in APA format?

To cite a literature review in APA style, you need to provide the author's name, the title of the article, and the year of publication. For example: Patel, A. B., & Stokes, G. S. (2012). The relationship between personality and intelligence: A meta-analysis of longitudinal research. Personality and Individual Differences, 53(1), 16-21

5. What are the components of a literature review?

• A brief introduction to the topic, including its background and context. The introduction should also include a rationale for why the study is being conducted and what it will accomplish.

• A description of the methodologies used in the study. This can include information about data collection methods, sample size, and statistical analyses.

• A presentation of the findings in an organized format that helps readers follow along with the author's conclusions.

6. What are common errors in writing literature review?

• Not spending enough time to critically evaluate the relevance of resources, observations and conclusions.

• Totally relying on secondary data while ignoring primary data.

• Letting your personal bias seep into your interpretation of existing literature.

• No detailed explanation of the procedure to discover and identify an appropriate literature review.

7. What are the 5 C's of writing literature review?

• Cite - the sources you utilized and referenced in your research.

• Compare - existing arguments, hypotheses, methodologies, and conclusions found in the knowledge base.

• Contrast - the arguments, topics, methodologies, approaches, and disputes that may be found in the literature.

• Critique - the literature and describe the ideas and opinions you find more convincing and why.

• Connect - the various studies you reviewed in your research.

8. How many sources should a literature review have?

When it is just a chapter, sources should equal the total number of pages in your article's body. if it is a self-contained paper in itself, you need at least three times as many sources as there are pages in your work.

9. Can literature review have diagrams?

• To represent an abstract idea or concept

• To explain the steps of a process or procedure

• To help readers understand the relationships between different concepts

10. How old should sources be in a literature review?

Sources for a literature review should be as current as possible or not older than ten years. The only exception to this rule is if you are reviewing a historical topic and need to use older sources.

11. What are the types of literature review?

• Argumentative review

• Integrative review

• Methodological review

• Systematic review

• Meta-analysis review

• Historical review

• Theoretical review

• Scoping review

• State-of-the-Art review

12. Is a literature review mandatory?

Yes. Literature review is a mandatory part of any research project. It is a critical step in the process that allows you to establish the scope of your research, and provide a background for the rest of your work.

But before you go,

• Six Online Tools for Easy Literature Review
• Evaluating literature review: systematic vs. scoping reviews
• Systematic Approaches to a Successful Literature Review
• Writing Integrative Literature Reviews: Guidelines and Examples

You might also like

Consensus GPT vs. SciSpace GPT: Choose the Best GPT for Research

Literature Review and Theoretical Framework: Understanding the Differences

Types of Essays in Academic Writing - Quick Guide (2024)

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• PLoS Comput Biol
• v.9(7); 2013 Jul

Ten Simple Rules for Writing a Literature Review

Marco pautasso.

1 Centre for Functional and Evolutionary Ecology (CEFE), CNRS, Montpellier, France

2 Centre for Biodiversity Synthesis and Analysis (CESAB), FRB, Aix-en-Provence, France

Literature reviews are in great demand in most scientific fields. Their need stems from the ever-increasing output of scientific publications [1] . For example, compared to 1991, in 2008 three, eight, and forty times more papers were indexed in Web of Science on malaria, obesity, and biodiversity, respectively [2] . Given such mountains of papers, scientists cannot be expected to examine in detail every single new paper relevant to their interests [3] . Thus, it is both advantageous and necessary to rely on regular summaries of the recent literature. Although recognition for scientists mainly comes from primary research, timely literature reviews can lead to new synthetic insights and are often widely read [4] . For such summaries to be useful, however, they need to be compiled in a professional way [5] .

When starting from scratch, reviewing the literature can require a titanic amount of work. That is why researchers who have spent their career working on a certain research issue are in a perfect position to review that literature. Some graduate schools are now offering courses in reviewing the literature, given that most research students start their project by producing an overview of what has already been done on their research issue [6] . However, it is likely that most scientists have not thought in detail about how to approach and carry out a literature review.

Reviewing the literature requires the ability to juggle multiple tasks, from finding and evaluating relevant material to synthesising information from various sources, from critical thinking to paraphrasing, evaluating, and citation skills [7] . In this contribution, I share ten simple rules I learned working on about 25 literature reviews as a PhD and postdoctoral student. Ideas and insights also come from discussions with coauthors and colleagues, as well as feedback from reviewers and editors.

Rule 1: Define a Topic and Audience

How to choose which topic to review? There are so many issues in contemporary science that you could spend a lifetime of attending conferences and reading the literature just pondering what to review. On the one hand, if you take several years to choose, several other people may have had the same idea in the meantime. On the other hand, only a well-considered topic is likely to lead to a brilliant literature review [8] . The topic must at least be:

• interesting to you (ideally, you should have come across a series of recent papers related to your line of work that call for a critical summary),
• an important aspect of the field (so that many readers will be interested in the review and there will be enough material to write it), and
• a well-defined issue (otherwise you could potentially include thousands of publications, which would make the review unhelpful).

Ideas for potential reviews may come from papers providing lists of key research questions to be answered [9] , but also from serendipitous moments during desultory reading and discussions. In addition to choosing your topic, you should also select a target audience. In many cases, the topic (e.g., web services in computational biology) will automatically define an audience (e.g., computational biologists), but that same topic may also be of interest to neighbouring fields (e.g., computer science, biology, etc.).

Rule 2: Search and Re-search the Literature

After having chosen your topic and audience, start by checking the literature and downloading relevant papers. Five pieces of advice here:

• keep track of the search items you use (so that your search can be replicated [10] ),
• keep a list of papers whose pdfs you cannot access immediately (so as to retrieve them later with alternative strategies),
• use a paper management system (e.g., Mendeley, Papers, Qiqqa, Sente),
• define early in the process some criteria for exclusion of irrelevant papers (these criteria can then be described in the review to help define its scope), and
• do not just look for research papers in the area you wish to review, but also seek previous reviews.

The chances are high that someone will already have published a literature review ( Figure 1 ), if not exactly on the issue you are planning to tackle, at least on a related topic. If there are already a few or several reviews of the literature on your issue, my advice is not to give up, but to carry on with your own literature review,

The bottom-right situation (many literature reviews but few research papers) is not just a theoretical situation; it applies, for example, to the study of the impacts of climate change on plant diseases, where there appear to be more literature reviews than research studies [33] .

• discussing in your review the approaches, limitations, and conclusions of past reviews,
• trying to find a new angle that has not been covered adequately in the previous reviews, and
• incorporating new material that has inevitably accumulated since their appearance.

When searching the literature for pertinent papers and reviews, the usual rules apply:

• be thorough,
• use different keywords and database sources (e.g., DBLP, Google Scholar, ISI Proceedings, JSTOR Search, Medline, Scopus, Web of Science), and
• look at who has cited past relevant papers and book chapters.

Rule 3: Take Notes While Reading

If you read the papers first, and only afterwards start writing the review, you will need a very good memory to remember who wrote what, and what your impressions and associations were while reading each single paper. My advice is, while reading, to start writing down interesting pieces of information, insights about how to organize the review, and thoughts on what to write. This way, by the time you have read the literature you selected, you will already have a rough draft of the review.

Of course, this draft will still need much rewriting, restructuring, and rethinking to obtain a text with a coherent argument [11] , but you will have avoided the danger posed by staring at a blank document. Be careful when taking notes to use quotation marks if you are provisionally copying verbatim from the literature. It is advisable then to reformulate such quotes with your own words in the final draft. It is important to be careful in noting the references already at this stage, so as to avoid misattributions. Using referencing software from the very beginning of your endeavour will save you time.

Rule 4: Choose the Type of Review You Wish to Write

After having taken notes while reading the literature, you will have a rough idea of the amount of material available for the review. This is probably a good time to decide whether to go for a mini- or a full review. Some journals are now favouring the publication of rather short reviews focusing on the last few years, with a limit on the number of words and citations. A mini-review is not necessarily a minor review: it may well attract more attention from busy readers, although it will inevitably simplify some issues and leave out some relevant material due to space limitations. A full review will have the advantage of more freedom to cover in detail the complexities of a particular scientific development, but may then be left in the pile of the very important papers “to be read” by readers with little time to spare for major monographs.

There is probably a continuum between mini- and full reviews. The same point applies to the dichotomy of descriptive vs. integrative reviews. While descriptive reviews focus on the methodology, findings, and interpretation of each reviewed study, integrative reviews attempt to find common ideas and concepts from the reviewed material [12] . A similar distinction exists between narrative and systematic reviews: while narrative reviews are qualitative, systematic reviews attempt to test a hypothesis based on the published evidence, which is gathered using a predefined protocol to reduce bias [13] , [14] . When systematic reviews analyse quantitative results in a quantitative way, they become meta-analyses. The choice between different review types will have to be made on a case-by-case basis, depending not just on the nature of the material found and the preferences of the target journal(s), but also on the time available to write the review and the number of coauthors [15] .

Rule 5: Keep the Review Focused, but Make It of Broad Interest

Whether your plan is to write a mini- or a full review, it is good advice to keep it focused 16 , 17 . Including material just for the sake of it can easily lead to reviews that are trying to do too many things at once. The need to keep a review focused can be problematic for interdisciplinary reviews, where the aim is to bridge the gap between fields [18] . If you are writing a review on, for example, how epidemiological approaches are used in modelling the spread of ideas, you may be inclined to include material from both parent fields, epidemiology and the study of cultural diffusion. This may be necessary to some extent, but in this case a focused review would only deal in detail with those studies at the interface between epidemiology and the spread of ideas.

While focus is an important feature of a successful review, this requirement has to be balanced with the need to make the review relevant to a broad audience. This square may be circled by discussing the wider implications of the reviewed topic for other disciplines.

Rule 6: Be Critical and Consistent

Reviewing the literature is not stamp collecting. A good review does not just summarize the literature, but discusses it critically, identifies methodological problems, and points out research gaps [19] . After having read a review of the literature, a reader should have a rough idea of:

• the major achievements in the reviewed field,
• the main areas of debate, and
• the outstanding research questions.

It is challenging to achieve a successful review on all these fronts. A solution can be to involve a set of complementary coauthors: some people are excellent at mapping what has been achieved, some others are very good at identifying dark clouds on the horizon, and some have instead a knack at predicting where solutions are going to come from. If your journal club has exactly this sort of team, then you should definitely write a review of the literature! In addition to critical thinking, a literature review needs consistency, for example in the choice of passive vs. active voice and present vs. past tense.

Rule 7: Find a Logical Structure

Like a well-baked cake, a good review has a number of telling features: it is worth the reader's time, timely, systematic, well written, focused, and critical. It also needs a good structure. With reviews, the usual subdivision of research papers into introduction, methods, results, and discussion does not work or is rarely used. However, a general introduction of the context and, toward the end, a recapitulation of the main points covered and take-home messages make sense also in the case of reviews. For systematic reviews, there is a trend towards including information about how the literature was searched (database, keywords, time limits) [20] .

How can you organize the flow of the main body of the review so that the reader will be drawn into and guided through it? It is generally helpful to draw a conceptual scheme of the review, e.g., with mind-mapping techniques. Such diagrams can help recognize a logical way to order and link the various sections of a review [21] . This is the case not just at the writing stage, but also for readers if the diagram is included in the review as a figure. A careful selection of diagrams and figures relevant to the reviewed topic can be very helpful to structure the text too [22] .

Rule 8: Make Use of Feedback

Reviews of the literature are normally peer-reviewed in the same way as research papers, and rightly so [23] . As a rule, incorporating feedback from reviewers greatly helps improve a review draft. Having read the review with a fresh mind, reviewers may spot inaccuracies, inconsistencies, and ambiguities that had not been noticed by the writers due to rereading the typescript too many times. It is however advisable to reread the draft one more time before submission, as a last-minute correction of typos, leaps, and muddled sentences may enable the reviewers to focus on providing advice on the content rather than the form.

Feedback is vital to writing a good review, and should be sought from a variety of colleagues, so as to obtain a diversity of views on the draft. This may lead in some cases to conflicting views on the merits of the paper, and on how to improve it, but such a situation is better than the absence of feedback. A diversity of feedback perspectives on a literature review can help identify where the consensus view stands in the landscape of the current scientific understanding of an issue [24] .

Rule 9: Include Your Own Relevant Research, but Be Objective

In many cases, reviewers of the literature will have published studies relevant to the review they are writing. This could create a conflict of interest: how can reviewers report objectively on their own work [25] ? Some scientists may be overly enthusiastic about what they have published, and thus risk giving too much importance to their own findings in the review. However, bias could also occur in the other direction: some scientists may be unduly dismissive of their own achievements, so that they will tend to downplay their contribution (if any) to a field when reviewing it.

In general, a review of the literature should neither be a public relations brochure nor an exercise in competitive self-denial. If a reviewer is up to the job of producing a well-organized and methodical review, which flows well and provides a service to the readership, then it should be possible to be objective in reviewing one's own relevant findings. In reviews written by multiple authors, this may be achieved by assigning the review of the results of a coauthor to different coauthors.

Rule 10: Be Up-to-Date, but Do Not Forget Older Studies

Given the progressive acceleration in the publication of scientific papers, today's reviews of the literature need awareness not just of the overall direction and achievements of a field of inquiry, but also of the latest studies, so as not to become out-of-date before they have been published. Ideally, a literature review should not identify as a major research gap an issue that has just been addressed in a series of papers in press (the same applies, of course, to older, overlooked studies (“sleeping beauties” [26] )). This implies that literature reviewers would do well to keep an eye on electronic lists of papers in press, given that it can take months before these appear in scientific databases. Some reviews declare that they have scanned the literature up to a certain point in time, but given that peer review can be a rather lengthy process, a full search for newly appeared literature at the revision stage may be worthwhile. Assessing the contribution of papers that have just appeared is particularly challenging, because there is little perspective with which to gauge their significance and impact on further research and society.

Inevitably, new papers on the reviewed topic (including independently written literature reviews) will appear from all quarters after the review has been published, so that there may soon be the need for an updated review. But this is the nature of science [27] – [32] . I wish everybody good luck with writing a review of the literature.

Acknowledgments

Many thanks to M. Barbosa, K. Dehnen-Schmutz, T. Döring, D. Fontaneto, M. Garbelotto, O. Holdenrieder, M. Jeger, D. Lonsdale, A. MacLeod, P. Mills, M. Moslonka-Lefebvre, G. Stancanelli, P. Weisberg, and X. Xu for insights and discussions, and to P. Bourne, T. Matoni, and D. Smith for helpful comments on a previous draft.

Funding Statement

This work was funded by the French Foundation for Research on Biodiversity (FRB) through its Centre for Synthesis and Analysis of Biodiversity data (CESAB), as part of the NETSEED research project. The funders had no role in the preparation of the manuscript.

Have a language expert improve your writing

Run a free plagiarism check in 10 minutes, automatically generate references for free.

• Knowledge Base
• Dissertation
• What is a Literature Review? | Guide, Template, & Examples

What is a Literature Review? | Guide, Template, & Examples

Published on 22 February 2022 by Shona McCombes . Revised on 7 June 2022.

What is a literature review? A literature review is a survey of scholarly sources on a specific topic. It provides an overview of current knowledge, allowing you to identify relevant theories, methods, and gaps in the existing research.

There are five key steps to writing a literature review:

• Search for relevant literature
• Evaluate sources
• Identify themes, debates and gaps
• Outline the structure
• Write your literature review

A good literature review doesn’t just summarise sources – it analyses, synthesises, and critically evaluates to give a clear picture of the state of knowledge on the subject.

Instantly correct all language mistakes in your text

Be assured that you'll submit flawless writing. Upload your document to correct all your mistakes.

Table of contents

Why write a literature review, examples of literature reviews, step 1: search for relevant literature, step 2: evaluate and select sources, step 3: identify themes, debates and gaps, step 4: outline your literature review’s structure, step 5: write your literature review, frequently asked questions about literature reviews, introduction.

• Quick Run-through
• Step 1 & 2

When you write a dissertation or thesis, you will have to conduct a literature review to situate your research within existing knowledge. The literature review gives you a chance to:

• Demonstrate your familiarity with the topic and scholarly context
• Develop a theoretical framework and methodology for your research
• Position yourself in relation to other researchers and theorists
• Show how your dissertation addresses a gap or contributes to a debate

You might also have to write a literature review as a stand-alone assignment. In this case, the purpose is to evaluate the current state of research and demonstrate your knowledge of scholarly debates around a topic.

The content will look slightly different in each case, but the process of conducting a literature review follows the same steps. We’ve written a step-by-step guide that you can follow below.

The only proofreading tool specialized in correcting academic writing

The academic proofreading tool has been trained on 1000s of academic texts and by native English editors. Making it the most accurate and reliable proofreading tool for students.

Correct my document today

Writing literature reviews can be quite challenging! A good starting point could be to look at some examples, depending on what kind of literature review you’d like to write.

• Example literature review #1: “Why Do People Migrate? A Review of the Theoretical Literature” ( Theoretical literature review about the development of economic migration theory from the 1950s to today.)
• Example literature review #2: “Literature review as a research methodology: An overview and guidelines” ( Methodological literature review about interdisciplinary knowledge acquisition and production.)
• Example literature review #3: “The Use of Technology in English Language Learning: A Literature Review” ( Thematic literature review about the effects of technology on language acquisition.)
• Example literature review #4: “Learners’ Listening Comprehension Difficulties in English Language Learning: A Literature Review” ( Chronological literature review about how the concept of listening skills has changed over time.)

You can also check out our templates with literature review examples and sample outlines at the links below.

Download Word doc Download Google doc

Before you begin searching for literature, you need a clearly defined topic .

If you are writing the literature review section of a dissertation or research paper, you will search for literature related to your research objectives and questions .

If you are writing a literature review as a stand-alone assignment, you will have to choose a focus and develop a central question to direct your search. Unlike a dissertation research question, this question has to be answerable without collecting original data. You should be able to answer it based only on a review of existing publications.

Make a list of keywords

Start by creating a list of keywords related to your research topic. Include each of the key concepts or variables you’re interested in, and list any synonyms and related terms. You can add to this list if you discover new keywords in the process of your literature search.

• Social media, Facebook, Instagram, Twitter, Snapchat, TikTok
• Body image, self-perception, self-esteem, mental health
• Generation Z, teenagers, adolescents, youth

Search for relevant sources

Use your keywords to begin searching for sources. Some databases to search for journals and articles include:

• Your university’s library catalogue
• Google Scholar
• Project Muse (humanities and social sciences)
• Medline (life sciences and biomedicine)
• EconLit (economics)
• Inspec (physics, engineering and computer science)

You can use boolean operators to help narrow down your search:

Read the abstract to find out whether an article is relevant to your question. When you find a useful book or article, you can check the bibliography to find other relevant sources.

To identify the most important publications on your topic, take note of recurring citations. If the same authors, books or articles keep appearing in your reading, make sure to seek them out.

You probably won’t be able to read absolutely everything that has been written on the topic – you’ll have to evaluate which sources are most relevant to your questions.

For each publication, ask yourself:

• What question or problem is the author addressing?
• What are the key concepts and how are they defined?
• What are the key theories, models and methods? Does the research use established frameworks or take an innovative approach?
• What are the results and conclusions of the study?
• How does the publication relate to other literature in the field? Does it confirm, add to, or challenge established knowledge?
• How does the publication contribute to your understanding of the topic? What are its key insights and arguments?
• What are the strengths and weaknesses of the research?

Make sure the sources you use are credible, and make sure you read any landmark studies and major theories in your field of research.

You can find out how many times an article has been cited on Google Scholar – a high citation count means the article has been influential in the field, and should certainly be included in your literature review.

The scope of your review will depend on your topic and discipline: in the sciences you usually only review recent literature, but in the humanities you might take a long historical perspective (for example, to trace how a concept has changed in meaning over time).

Remember that you can use our template to summarise and evaluate sources you’re thinking about using!

Take notes and cite your sources

As you read, you should also begin the writing process. Take notes that you can later incorporate into the text of your literature review.

It’s important to keep track of your sources with references to avoid plagiarism . It can be helpful to make an annotated bibliography, where you compile full reference information and write a paragraph of summary and analysis for each source. This helps you remember what you read and saves time later in the process.

You can use our free APA Reference Generator for quick, correct, consistent citations.

To begin organising your literature review’s argument and structure, you need to understand the connections and relationships between the sources you’ve read. Based on your reading and notes, you can look for:

• Trends and patterns (in theory, method or results): do certain approaches become more or less popular over time?
• Themes: what questions or concepts recur across the literature?
• Debates, conflicts and contradictions: where do sources disagree?
• Pivotal publications: are there any influential theories or studies that changed the direction of the field?
• Gaps: what is missing from the literature? Are there weaknesses that need to be addressed?

This step will help you work out the structure of your literature review and (if applicable) show how your own research will contribute to existing knowledge.

• Most research has focused on young women.
• There is an increasing interest in the visual aspects of social media.
• But there is still a lack of robust research on highly-visual platforms like Instagram and Snapchat – this is a gap that you could address in your own research.

There are various approaches to organising the body of a literature review. You should have a rough idea of your strategy before you start writing.

Depending on the length of your literature review, you can combine several of these strategies (for example, your overall structure might be thematic, but each theme is discussed chronologically).

Chronological

The simplest approach is to trace the development of the topic over time. However, if you choose this strategy, be careful to avoid simply listing and summarising sources in order.

Try to analyse patterns, turning points and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred.

If you have found some recurring central themes, you can organise your literature review into subsections that address different aspects of the topic.

For example, if you are reviewing literature about inequalities in migrant health outcomes, key themes might include healthcare policy, language barriers, cultural attitudes, legal status, and economic access.

Methodological

If you draw your sources from different disciplines or fields that use a variety of research methods , you might want to compare the results and conclusions that emerge from different approaches. For example:

• Look at what results have emerged in qualitative versus quantitative research
• Discuss how the topic has been approached by empirical versus theoretical scholarship
• Divide the literature into sociological, historical, and cultural sources

Theoretical

A literature review is often the foundation for a theoretical framework . You can use it to discuss various theories, models, and definitions of key concepts.

You might argue for the relevance of a specific theoretical approach, or combine various theoretical concepts to create a framework for your research.

Like any other academic text, your literature review should have an introduction , a main body, and a conclusion . What you include in each depends on the objective of your literature review.

The introduction should clearly establish the focus and purpose of the literature review.

If you are writing the literature review as part of your dissertation or thesis, reiterate your central problem or research question and give a brief summary of the scholarly context. You can emphasise the timeliness of the topic (“many recent studies have focused on the problem of x”) or highlight a gap in the literature (“while there has been much research on x, few researchers have taken y into consideration”).

Depending on the length of your literature review, you might want to divide the body into subsections. You can use a subheading for each theme, time period, or methodological approach.

As you write, make sure to follow these tips:

• Summarise and synthesise: give an overview of the main points of each source and combine them into a coherent whole.
• Analyse and interpret: don’t just paraphrase other researchers – add your own interpretations, discussing the significance of findings in relation to the literature as a whole.
• Critically evaluate: mention the strengths and weaknesses of your sources.
• Write in well-structured paragraphs: use transitions and topic sentences to draw connections, comparisons and contrasts.

In the conclusion, you should summarise the key findings you have taken from the literature and emphasise their significance.

If the literature review is part of your dissertation or thesis, reiterate how your research addresses gaps and contributes new knowledge, or discuss how you have drawn on existing theories and methods to build a framework for your research. This can lead directly into your methodology section.

A literature review is a survey of scholarly sources (such as books, journal articles, and theses) related to a specific topic or research question .

It is often written as part of a dissertation , thesis, research paper , or proposal .

There are several reasons to conduct a literature review at the beginning of a research project:

• To familiarise yourself with the current state of knowledge on your topic
• To ensure that you’re not just repeating what others have already done
• To identify gaps in knowledge and unresolved problems that your research can address
• To develop your theoretical framework and methodology
• To provide an overview of the key findings and debates on the topic

Writing the literature review shows your reader how your work relates to existing research and what new insights it will contribute.

The literature review usually comes near the beginning of your  dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the ‘Cite this Scribbr article’ button to automatically add the citation to our free Reference Generator.

McCombes, S. (2022, June 07). What is a Literature Review? | Guide, Template, & Examples. Scribbr. Retrieved 9 April 2024, from https://www.scribbr.co.uk/thesis-dissertation/literature-review/

Is this article helpful?

Shona McCombes

Other students also liked, how to write a dissertation proposal | a step-by-step guide, what is a theoretical framework | a step-by-step guide, what is a research methodology | steps & tips.

Harvey Cushing/John Hay Whitney Medical Library

• Collections
• Research Help

YSN Doctoral Programs: Steps in Conducting a Literature Review

• Biomedical Databases
• Global (Public Health) Databases
• Soc. Sci., History, and Law Databases
• Grey Literature
• Trials Registers
• Data and Statistics
• Public Policy
• Google Tips
• Recommended Books
• Steps in Conducting a Literature Review

What is a literature review?

A literature review is an integrated analysis -- not just a summary-- of scholarly writings and other relevant evidence related directly to your research question.  That is, it represents a synthesis of the evidence that provides background information on your topic and shows a association between the evidence and your research question.

A literature review may be a stand alone work or the introduction to a larger research paper, depending on the assignment.  Rely heavily on the guidelines your instructor has given you.

Why is it important?

A literature review is important because it:

• Explains the background of research on a topic.
• Demonstrates why a topic is significant to a subject area.
• Discovers relationships between research studies/ideas.
• Identifies major themes, concepts, and researchers on a topic.
• Identifies critical gaps and points of disagreement.
• Discusses further research questions that logically come out of the previous studies.

APA7 Style resources

APA Style Blog - for those harder to find answers

1. Choose a topic. Define your research question.

Your literature review should be guided by your central research question.  The literature represents background and research developments related to a specific research question, interpreted and analyzed by you in a synthesized way.

• Make sure your research question is not too broad or too narrow.  Is it manageable?
• Begin writing down terms that are related to your question. These will be useful for searches later.
• If you have the opportunity, discuss your topic with your professor and your class mates.

2. Decide on the scope of your review

How many studies do you need to look at? How comprehensive should it be? How many years should it cover? 

• This may depend on your assignment.  How many sources does the assignment require?

3. Select the databases you will use to conduct your searches.

Make a list of the databases you will search. 

Where to find databases:

• use the tabs on this guide
• Find other databases in the Nursing Information Resources web page
• More on the Medical Library web page
• ... and more on the Yale University Library web page

4. Conduct your searches to find the evidence. Keep track of your searches.

• Use the key words in your question, as well as synonyms for those words, as terms in your search. Use the database tutorials for help.
• Save the searches in the databases. This saves time when you want to redo, or modify, the searches. It is also helpful to use as a guide is the searches are not finding any useful results.
• Review the abstracts of research studies carefully. This will save you time.
• Use the bibliographies and references of research studies you find to locate others.
• Check with your professor, or a subject expert in the field, if you are missing any key works in the field.
• Ask your librarian for help at any time.
• Use a citation manager, such as EndNote as the repository for your citations. See the EndNote tutorials for help.

Review the literature

Some questions to help you analyze the research:

• What was the research question of the study you are reviewing? What were the authors trying to discover?
• Was the research funded by a source that could influence the findings?
• What were the research methodologies? Analyze its literature review, the samples and variables used, the results, and the conclusions.
• Does the research seem to be complete? Could it have been conducted more soundly? What further questions does it raise?
• If there are conflicting studies, why do you think that is?
• How are the authors viewed in the field? Has this study been cited? If so, how has it been analyzed?

Tips: 

• Review the abstracts carefully.  
• Keep careful notes so that you may track your thought processes during the research process.
• Create a matrix of the studies for easy analysis, and synthesis, across all of the studies.
• << Previous: Recommended Books
• Last Updated: Jan 4, 2024 10:52 AM
• URL: https://guides.library.yale.edu/YSNDoctoral

Reference management. Clean and simple.

Literature review

How to write a literature review in 6 steps

How do you write a good literature review? This step-by-step guide on how to write an excellent literature review covers all aspects of planning and writing literature reviews for academic papers and theses.

How to write a systematic literature review [9 steps]

How do you write a systematic literature review? What types of systematic literature reviews exist and where do you use them? Learn everything you need to know about a systematic literature review in this guide

What is a literature review? [with examples]

Not sure what a literature review is? This guide covers the definition, purpose, and format of a literature review.

Literature Reviews

What this handout is about.

This handout will explain what literature reviews are and offer insights into the form and construction of literature reviews in the humanities, social sciences, and sciences.

Introduction

OK. You’ve got to write a literature review. You dust off a novel and a book of poetry, settle down in your chair, and get ready to issue a “thumbs up” or “thumbs down” as you leaf through the pages. “Literature review” done. Right?

Wrong! The “literature” of a literature review refers to any collection of materials on a topic, not necessarily the great literary texts of the world. “Literature” could be anything from a set of government pamphlets on British colonial methods in Africa to scholarly articles on the treatment of a torn ACL. And a review does not necessarily mean that your reader wants you to give your personal opinion on whether or not you liked these sources.

What is a literature review, then?

A literature review discusses published information in a particular subject area, and sometimes information in a particular subject area within a certain time period.

A literature review can be just a simple summary of the sources, but it usually has an organizational pattern and combines both summary and synthesis. A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information. It might give a new interpretation of old material or combine new with old interpretations. Or it might trace the intellectual progression of the field, including major debates. And depending on the situation, the literature review may evaluate the sources and advise the reader on the most pertinent or relevant.

But how is a literature review different from an academic research paper?

The main focus of an academic research paper is to develop a new argument, and a research paper is likely to contain a literature review as one of its parts. In a research paper, you use the literature as a foundation and as support for a new insight that you contribute. The focus of a literature review, however, is to summarize and synthesize the arguments and ideas of others without adding new contributions.

Why do we write literature reviews?

Literature reviews provide you with a handy guide to a particular topic. If you have limited time to conduct research, literature reviews can give you an overview or act as a stepping stone. For professionals, they are useful reports that keep them up to date with what is current in the field. For scholars, the depth and breadth of the literature review emphasizes the credibility of the writer in his or her field. Literature reviews also provide a solid background for a research paper’s investigation. Comprehensive knowledge of the literature of the field is essential to most research papers.

Who writes these things, anyway?

Literature reviews are written occasionally in the humanities, but mostly in the sciences and social sciences; in experiment and lab reports, they constitute a section of the paper. Sometimes a literature review is written as a paper in itself.

Let’s get to it! What should I do before writing the literature review?

If your assignment is not very specific, seek clarification from your instructor:

• Roughly how many sources should you include?
• What types of sources (books, journal articles, websites)?
• Should you summarize, synthesize, or critique your sources by discussing a common theme or issue?
• Should you evaluate your sources?
• Should you provide subheadings and other background information, such as definitions and/or a history?

Find models

Look for other literature reviews in your area of interest or in the discipline and read them to get a sense of the types of themes you might want to look for in your own research or ways to organize your final review. You can simply put the word “review” in your search engine along with your other topic terms to find articles of this type on the Internet or in an electronic database. The bibliography or reference section of sources you’ve already read are also excellent entry points into your own research.

Narrow your topic

There are hundreds or even thousands of articles and books on most areas of study. The narrower your topic, the easier it will be to limit the number of sources you need to read in order to get a good survey of the material. Your instructor will probably not expect you to read everything that’s out there on the topic, but you’ll make your job easier if you first limit your scope.

Keep in mind that UNC Libraries have research guides and to databases relevant to many fields of study. You can reach out to the subject librarian for a consultation: https://library.unc.edu/support/consultations/ .

And don’t forget to tap into your professor’s (or other professors’) knowledge in the field. Ask your professor questions such as: “If you had to read only one book from the 90’s on topic X, what would it be?” Questions such as this help you to find and determine quickly the most seminal pieces in the field.

Consider whether your sources are current

Some disciplines require that you use information that is as current as possible. In the sciences, for instance, treatments for medical problems are constantly changing according to the latest studies. Information even two years old could be obsolete. However, if you are writing a review in the humanities, history, or social sciences, a survey of the history of the literature may be what is needed, because what is important is how perspectives have changed through the years or within a certain time period. Try sorting through some other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to consider what is currently of interest to scholars in this field and what is not.

Strategies for writing the literature review

Find a focus.

A literature review, like a term paper, is usually organized around ideas, not the sources themselves as an annotated bibliography would be organized. This means that you will not just simply list your sources and go into detail about each one of them, one at a time. No. As you read widely but selectively in your topic area, consider instead what themes or issues connect your sources together. Do they present one or different solutions? Is there an aspect of the field that is missing? How well do they present the material and do they portray it according to an appropriate theory? Do they reveal a trend in the field? A raging debate? Pick one of these themes to focus the organization of your review.

Convey it to your reader

A literature review may not have a traditional thesis statement (one that makes an argument), but you do need to tell readers what to expect. Try writing a simple statement that lets the reader know what is your main organizing principle. Here are a couple of examples:

The current trend in treatment for congestive heart failure combines surgery and medicine. More and more cultural studies scholars are accepting popular media as a subject worthy of academic consideration.

Consider organization

You’ve got a focus, and you’ve stated it clearly and directly. Now what is the most effective way of presenting the information? What are the most important topics, subtopics, etc., that your review needs to include? And in what order should you present them? Develop an organization for your review at both a global and local level:

First, cover the basic categories

Just like most academic papers, literature reviews also must contain at least three basic elements: an introduction or background information section; the body of the review containing the discussion of sources; and, finally, a conclusion and/or recommendations section to end the paper. The following provides a brief description of the content of each:

• Introduction: Gives a quick idea of the topic of the literature review, such as the central theme or organizational pattern.
• Body: Contains your discussion of sources and is organized either chronologically, thematically, or methodologically (see below for more information on each).
• Conclusions/Recommendations: Discuss what you have drawn from reviewing literature so far. Where might the discussion proceed?

Organizing the body

Once you have the basic categories in place, then you must consider how you will present the sources themselves within the body of your paper. Create an organizational method to focus this section even further.

To help you come up with an overall organizational framework for your review, consider the following scenario:

You’ve decided to focus your literature review on materials dealing with sperm whales. This is because you’ve just finished reading Moby Dick, and you wonder if that whale’s portrayal is really real. You start with some articles about the physiology of sperm whales in biology journals written in the 1980’s. But these articles refer to some British biological studies performed on whales in the early 18th century. So you check those out. Then you look up a book written in 1968 with information on how sperm whales have been portrayed in other forms of art, such as in Alaskan poetry, in French painting, or on whale bone, as the whale hunters in the late 19th century used to do. This makes you wonder about American whaling methods during the time portrayed in Moby Dick, so you find some academic articles published in the last five years on how accurately Herman Melville portrayed the whaling scene in his novel.

Now consider some typical ways of organizing the sources into a review:

• Chronological: If your review follows the chronological method, you could write about the materials above according to when they were published. For instance, first you would talk about the British biological studies of the 18th century, then about Moby Dick, published in 1851, then the book on sperm whales in other art (1968), and finally the biology articles (1980s) and the recent articles on American whaling of the 19th century. But there is relatively no continuity among subjects here. And notice that even though the sources on sperm whales in other art and on American whaling are written recently, they are about other subjects/objects that were created much earlier. Thus, the review loses its chronological focus.
• By publication: Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on biological studies of sperm whales if the progression revealed a change in dissection practices of the researchers who wrote and/or conducted the studies.
• By trend: A better way to organize the above sources chronologically is to examine the sources under another trend, such as the history of whaling. Then your review would have subsections according to eras within this period. For instance, the review might examine whaling from pre-1600-1699, 1700-1799, and 1800-1899. Under this method, you would combine the recent studies on American whaling in the 19th century with Moby Dick itself in the 1800-1899 category, even though the authors wrote a century apart.
• Thematic: Thematic reviews of literature are organized around a topic or issue, rather than the progression of time. However, progression of time may still be an important factor in a thematic review. For instance, the sperm whale review could focus on the development of the harpoon for whale hunting. While the study focuses on one topic, harpoon technology, it will still be organized chronologically. The only difference here between a “chronological” and a “thematic” approach is what is emphasized the most: the development of the harpoon or the harpoon technology.But more authentic thematic reviews tend to break away from chronological order. For instance, a thematic review of material on sperm whales might examine how they are portrayed as “evil” in cultural documents. The subsections might include how they are personified, how their proportions are exaggerated, and their behaviors misunderstood. A review organized in this manner would shift between time periods within each section according to the point made.
• Methodological: A methodological approach differs from the two above in that the focusing factor usually does not have to do with the content of the material. Instead, it focuses on the “methods” of the researcher or writer. For the sperm whale project, one methodological approach would be to look at cultural differences between the portrayal of whales in American, British, and French art work. Or the review might focus on the economic impact of whaling on a community. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed. Once you’ve decided on the organizational method for the body of the review, the sections you need to include in the paper should be easy to figure out. They should arise out of your organizational strategy. In other words, a chronological review would have subsections for each vital time period. A thematic review would have subtopics based upon factors that relate to the theme or issue.

Sometimes, though, you might need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you. Put in only what is necessary. Here are a few other sections you might want to consider:

• Current Situation: Information necessary to understand the topic or focus of the literature review.
• History: The chronological progression of the field, the literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
• Methods and/or Standards: The criteria you used to select the sources in your literature review or the way in which you present your information. For instance, you might explain that your review includes only peer-reviewed articles and journals.

Questions for Further Research: What questions about the field has the review sparked? How will you further your research as a result of the review?

Begin composing

Once you’ve settled on a general pattern of organization, you’re ready to write each section. There are a few guidelines you should follow during the writing stage as well. Here is a sample paragraph from a literature review about sexism and language to illuminate the following discussion:

However, other studies have shown that even gender-neutral antecedents are more likely to produce masculine images than feminine ones (Gastil, 1990). Hamilton (1988) asked students to complete sentences that required them to fill in pronouns that agreed with gender-neutral antecedents such as “writer,” “pedestrian,” and “persons.” The students were asked to describe any image they had when writing the sentence. Hamilton found that people imagined 3.3 men to each woman in the masculine “generic” condition and 1.5 men per woman in the unbiased condition. Thus, while ambient sexism accounted for some of the masculine bias, sexist language amplified the effect. (Source: Erika Falk and Jordan Mills, “Why Sexist Language Affects Persuasion: The Role of Homophily, Intended Audience, and Offense,” Women and Language19:2).

Use evidence

In the example above, the writers refer to several other sources when making their point. A literature review in this sense is just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence to show that what you are saying is valid.

Be selective

Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the review’s focus, whether it is thematic, methodological, or chronological.

Use quotes sparingly

Falk and Mills do not use any direct quotes. That is because the survey nature of the literature review does not allow for in-depth discussion or detailed quotes from the text. Some short quotes here and there are okay, though, if you want to emphasize a point, or if what the author said just cannot be rewritten in your own words. Notice that Falk and Mills do quote certain terms that were coined by the author, not common knowledge, or taken directly from the study. But if you find yourself wanting to put in more quotes, check with your instructor.

Summarize and synthesize

Remember to summarize and synthesize your sources within each paragraph as well as throughout the review. The authors here recapitulate important features of Hamilton’s study, but then synthesize it by rephrasing the study’s significance and relating it to their own work.

Keep your own voice

While the literature review presents others’ ideas, your voice (the writer’s) should remain front and center. Notice that Falk and Mills weave references to other sources into their own text, but they still maintain their own voice by starting and ending the paragraph with their own ideas and their own words. The sources support what Falk and Mills are saying.

Use caution when paraphrasing

When paraphrasing a source that is not your own, be sure to represent the author’s information or opinions accurately and in your own words. In the preceding example, Falk and Mills either directly refer in the text to the author of their source, such as Hamilton, or they provide ample notation in the text when the ideas they are mentioning are not their own, for example, Gastil’s. For more information, please see our handout on plagiarism .

Revise, revise, revise

Draft in hand? Now you’re ready to revise. Spending a lot of time revising is a wise idea, because your main objective is to present the material, not the argument. So check over your review again to make sure it follows the assignment and/or your outline. Then, just as you would for most other academic forms of writing, rewrite or rework the language of your review so that you’ve presented your information in the most concise manner possible. Be sure to use terminology familiar to your audience; get rid of unnecessary jargon or slang. Finally, double check that you’ve documented your sources and formatted the review appropriately for your discipline. For tips on the revising and editing process, see our handout on revising drafts .

Works consulted

We consulted these works while writing this handout. This is not a comprehensive list of resources on the handout’s topic, and we encourage you to do your own research to find additional publications. Please do not use this list as a model for the format of your own reference list, as it may not match the citation style you are using. For guidance on formatting citations, please see the UNC Libraries citation tutorial . We revise these tips periodically and welcome feedback.

Anson, Chris M., and Robert A. Schwegler. 2010. The Longman Handbook for Writers and Readers , 6th ed. New York: Longman.

Jones, Robert, Patrick Bizzaro, and Cynthia Selfe. 1997. The Harcourt Brace Guide to Writing in the Disciplines . New York: Harcourt Brace.

Lamb, Sandra E. 1998. How to Write It: A Complete Guide to Everything You’ll Ever Write . Berkeley: Ten Speed Press.

Rosen, Leonard J., and Laurence Behrens. 2003. The Allyn & Bacon Handbook , 5th ed. New York: Longman.

Troyka, Lynn Quittman, and Doug Hesse. 2016. Simon and Schuster Handbook for Writers , 11th ed. London: Pearson.

You may reproduce it for non-commercial use if you use the entire handout and attribute the source: The Writing Center, University of North Carolina at Chapel Hill

Make a Gift

• University of Texas Libraries

Literature Reviews

• What is a literature review?
• Steps in the Literature Review Process
• Define your research question
• Determine inclusion and exclusion criteria
• Choose databases and search
• Review Results
• Synthesize Results
• Analyze Results
• Librarian Support

What is a Literature Review?

A literature or narrative review is a comprehensive review and analysis of the published literature on a specific topic or research question. The literature that is reviewed contains: books, articles, academic articles, conference proceedings, association papers, and dissertations. It contains the most pertinent studies and points to important past and current research and practices. It provides background and context, and shows how your research will contribute to the field. 

A literature review should: 

• Provide a comprehensive and updated review of the literature;
• Explain why this review has taken place;
• Articulate a position or hypothesis;
• Acknowledge and account for conflicting and corroborating points of view

From  S age Research Methods

Purpose of a Literature Review

A literature review can be written as an introduction to a study to:

• Demonstrate how a study fills a gap in research
• Compare a study with other research that's been done

Or it can be a separate work (a research article on its own) which:

• Organizes or describes a topic
• Describes variables within a particular issue/problem

Limitations of a Literature Review

Some of the limitations of a literature review are:

• It's a snapshot in time. Unlike other reviews, this one has beginning, a middle and an end. There may be future developments that could make your work less relevant.
• It may be too focused. Some niche studies may miss the bigger picture.
• It can be difficult to be comprehensive. There is no way to make sure all the literature on a topic was considered.
• It is easy to be biased if you stick to top tier journals. There may be other places where people are publishing exemplary research. Look to open access publications and conferences to reflect a more inclusive collection. Also, make sure to include opposing views (and not just supporting evidence).

Source: Grant, Maria J., and Andrew Booth. “A Typology of Reviews: An Analysis of 14 Review Types and Associated Methodologies.” Health Information & Libraries Journal, vol. 26, no. 2, June 2009, pp. 91–108. Wiley Online Library, doi:10.1111/j.1471-1842.2009.00848.x.

Meryl Brodsky : Communication and Information Studies

Hannah Chapman Tripp : Biology, Neuroscience

Carolyn Cunningham : Human Development & Family Sciences, Psychology, Sociology

Larayne Dallas : Engineering

Janelle Hedstrom : Special Education, Curriculum & Instruction, Ed Leadership & Policy ​

Susan Macicak : Linguistics

Imelda Vetter : Dell Medical School

For help in other subject areas, please see the guide to library specialists by subject .

Periodically, UT Libraries runs a workshop covering the basics and library support for literature reviews. While we try to offer these once per academic year, we find providing the recording to be helpful to community members who have missed the session. Following is the most recent recording of the workshop, Conducting a Literature Review. To view the recording, a UT login is required.

• October 26, 2022 recording
• Last Updated: Oct 26, 2022 2:49 PM
• URL: https://guides.lib.utexas.edu/literaturereviews

Libraries | Research Guides

Literature reviews, what is a literature review, learning more about how to do a literature review.

• Planning the Review
• The Research Question
• Choosing Where to Search
• Organizing the Review
• Writing the Review

A literature review is a review and synthesis of existing research on a topic or research question. A literature review is meant to analyze the scholarly literature, make connections across writings and identify strengths, weaknesses, trends, and missing conversations. A literature review should address different aspects of a topic as it relates to your research question. A literature review goes beyond a description or summary of the literature you have read. 

• Sage Research Methods Core Collection This link opens in a new window SAGE Research Methods supports research at all levels by providing material to guide users through every step of the research process. SAGE Research Methods is the ultimate methods library with more than 1000 books, reference works, journal articles, and instructional videos by world-leading academics from across the social sciences, including the largest collection of qualitative methods books available online from any scholarly publisher. – Publisher

• Next: Planning the Review >>
• Last Updated: Jan 17, 2024 10:05 AM
• URL: https://libguides.northwestern.edu/literaturereviews

News alert: UC Berkeley has announced its next university librarian

Secondary menu

• Log in to your Library account
• Hours and Maps
• Connect from Off Campus
• UC Berkeley Home

Search form

Conducting a literature review: why do a literature review, why do a literature review.

• How To Find "The Literature"
• Found it -- Now What?

Besides the obvious reason for students -- because it is assigned! -- a literature review helps you explore the research that has come before you, to see how your research question has (or has not) already been addressed.

You identify:

• core research in the field
• experts in the subject area
• methodology you may want to use (or avoid)
• gaps in knowledge -- or where your research would fit in

It Also Helps You:

• Publish and share your findings
• Justify requests for grants and other funding
• Identify best practices to inform practice
• Set wider context for a program evaluation
• Compile information to support community organizing

Great brief overview, from NCSU

Want To Know More?

• Next: How To Find "The Literature" >>
• Last Updated: Dec 8, 2023 10:11 AM
• URL: https://guides.lib.berkeley.edu/litreview

• USC Libraries
• Research Guides

Organizing Your Social Sciences Research Paper

• 5. The Literature Review
• Purpose of Guide
• Design Flaws to Avoid
• Independent and Dependent Variables
• Glossary of Research Terms
• Reading Research Effectively
• Narrowing a Topic Idea
• Broadening a Topic Idea
• Extending the Timeliness of a Topic Idea
• Academic Writing Style
• Applying Critical Thinking
• Choosing a Title
• Making an Outline
• Paragraph Development
• Research Process Video Series
• Executive Summary
• The C.A.R.S. Model
• Background Information
• The Research Problem/Question
• Theoretical Framework
• Citation Tracking
• Content Alert Services
• Evaluating Sources
• Primary Sources
• Secondary Sources
• Tiertiary Sources
• Scholarly vs. Popular Publications
• Qualitative Methods
• Quantitative Methods
• Insiderness
• Using Non-Textual Elements
• Limitations of the Study
• Common Grammar Mistakes
• Writing Concisely
• Avoiding Plagiarism
• Footnotes or Endnotes?
• Further Readings
• Generative AI and Writing
• USC Libraries Tutorials and Other Guides
• Bibliography

A literature review surveys prior research published in books, scholarly articles, and any other sources relevant to a particular issue, area of research, or theory, and by so doing, provides a description, summary, and critical evaluation of these works in relation to the research problem being investigated. Literature reviews are designed to provide an overview of sources you have used in researching a particular topic and to demonstrate to your readers how your research fits within existing scholarship about the topic.

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . Fourth edition. Thousand Oaks, CA: SAGE, 2014.

Importance of a Good Literature Review

A literature review may consist of simply a summary of key sources, but in the social sciences, a literature review usually has an organizational pattern and combines both summary and synthesis, often within specific conceptual categories . A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information in a way that informs how you are planning to investigate a research problem. The analytical features of a literature review might:

• Give a new interpretation of old material or combine new with old interpretations,
• Trace the intellectual progression of the field, including major debates,
• Depending on the situation, evaluate the sources and advise the reader on the most pertinent or relevant research, or
• Usually in the conclusion of a literature review, identify where gaps exist in how a problem has been researched to date.

Given this, the purpose of a literature review is to:

• Place each work in the context of its contribution to understanding the research problem being studied.
• Describe the relationship of each work to the others under consideration.
• Identify new ways to interpret prior research.
• Reveal any gaps that exist in the literature.
• Resolve conflicts amongst seemingly contradictory previous studies.
• Identify areas of prior scholarship to prevent duplication of effort.
• Point the way in fulfilling a need for additional research.
• Locate your own research within the context of existing literature [very important].

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . Los Angeles, CA: SAGE, 2011; Knopf, Jeffrey W. "Doing a Literature Review." PS: Political Science and Politics 39 (January 2006): 127-132; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012.

Types of Literature Reviews

It is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the primary studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally among scholars that become part of the body of epistemological traditions within the field.

In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews. Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are a number of approaches you could adopt depending upon the type of analysis underpinning your study.

Argumentative Review This form examines literature selectively in order to support or refute an argument, deeply embedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to make summary claims of the sort found in systematic reviews [see below].

Integrative Review Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses or research problems. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication. This is the most common form of review in the social sciences.

Historical Review Few things rest in isolation from historical precedent. Historical literature reviews focus on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.

Methodological Review A review does not always focus on what someone said [findings], but how they came about saying what they say [method of analysis]. Reviewing methods of analysis provides a framework of understanding at different levels [i.e. those of theory, substantive fields, research approaches, and data collection and analysis techniques], how researchers draw upon a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection, and data analysis. This approach helps highlight ethical issues which you should be aware of and consider as you go through your own study.

Systematic Review This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyze data from the studies that are included in the review. The goal is to deliberately document, critically evaluate, and summarize scientifically all of the research about a clearly defined research problem . Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?" This type of literature review is primarily applied to examining prior research studies in clinical medicine and allied health fields, but it is increasingly being used in the social sciences.

Theoretical Review The purpose of this form is to examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review helps to establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.

NOTE : Most often the literature review will incorporate some combination of types. For example, a review that examines literature supporting or refuting an argument, assumption, or philosophical problem related to the research problem will also need to include writing supported by sources that establish the history of these arguments in the literature.

Baumeister, Roy F. and Mark R. Leary. "Writing Narrative Literature Reviews."  Review of General Psychology 1 (September 1997): 311-320; Mark R. Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147; Petticrew, Mark and Helen Roberts. Systematic Reviews in the Social Sciences: A Practical Guide . Malden, MA: Blackwell Publishers, 2006; Torracro, Richard. "Writing Integrative Literature Reviews: Guidelines and Examples." Human Resource Development Review 4 (September 2005): 356-367; Rocco, Tonette S. and Maria S. Plakhotnik. "Literature Reviews, Conceptual Frameworks, and Theoretical Frameworks: Terms, Functions, and Distinctions." Human Ressource Development Review 8 (March 2008): 120-130; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

Structure and Writing Style

I.  Thinking About Your Literature Review

The structure of a literature review should include the following in support of understanding the research problem :

• An overview of the subject, issue, or theory under consideration, along with the objectives of the literature review,
• Division of works under review into themes or categories [e.g. works that support a particular position, those against, and those offering alternative approaches entirely],
• An explanation of how each work is similar to and how it varies from the others,
• Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research.

The critical evaluation of each work should consider :

• Provenance -- what are the author's credentials? Are the author's arguments supported by evidence [e.g. primary historical material, case studies, narratives, statistics, recent scientific findings]?
• Methodology -- were the techniques used to identify, gather, and analyze the data appropriate to addressing the research problem? Was the sample size appropriate? Were the results effectively interpreted and reported?
• Objectivity -- is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
• Persuasiveness -- which of the author's theses are most convincing or least convincing?
• Validity -- are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?

II.  Development of the Literature Review

Four Basic Stages of Writing 1.  Problem formulation -- which topic or field is being examined and what are its component issues? 2.  Literature search -- finding materials relevant to the subject being explored. 3.  Data evaluation -- determining which literature makes a significant contribution to the understanding of the topic. 4.  Analysis and interpretation -- discussing the findings and conclusions of pertinent literature.

Consider the following issues before writing the literature review: Clarify If your assignment is not specific about what form your literature review should take, seek clarification from your professor by asking these questions: 1.  Roughly how many sources would be appropriate to include? 2.  What types of sources should I review (books, journal articles, websites; scholarly versus popular sources)? 3.  Should I summarize, synthesize, or critique sources by discussing a common theme or issue? 4.  Should I evaluate the sources in any way beyond evaluating how they relate to understanding the research problem? 5.  Should I provide subheadings and other background information, such as definitions and/or a history? Find Models Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature review sections. Read them to get a sense of the types of themes you might want to look for in your own research or to identify ways to organize your final review. The bibliography or reference section of sources you've already read, such as required readings in the course syllabus, are also excellent entry points into your own research. Narrow the Topic The narrower your topic, the easier it will be to limit the number of sources you need to read in order to obtain a good survey of relevant resources. Your professor will probably not expect you to read everything that's available about the topic, but you'll make the act of reviewing easier if you first limit scope of the research problem. A good strategy is to begin by searching the USC Libraries Catalog for recent books about the topic and review the table of contents for chapters that focuses on specific issues. You can also review the indexes of books to find references to specific issues that can serve as the focus of your research. For example, a book surveying the history of the Israeli-Palestinian conflict may include a chapter on the role Egypt has played in mediating the conflict, or look in the index for the pages where Egypt is mentioned in the text. Consider Whether Your Sources are Current Some disciplines require that you use information that is as current as possible. This is particularly true in disciplines in medicine and the sciences where research conducted becomes obsolete very quickly as new discoveries are made. However, when writing a review in the social sciences, a survey of the history of the literature may be required. In other words, a complete understanding the research problem requires you to deliberately examine how knowledge and perspectives have changed over time. Sort through other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to explore what is considered by scholars to be a "hot topic" and what is not.

III.  Ways to Organize Your Literature Review

Chronology of Events If your review follows the chronological method, you could write about the materials according to when they were published. This approach should only be followed if a clear path of research building on previous research can be identified and that these trends follow a clear chronological order of development. For example, a literature review that focuses on continuing research about the emergence of German economic power after the fall of the Soviet Union. By Publication Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on environmental studies of brown fields if the progression revealed, for example, a change in the soil collection practices of the researchers who wrote and/or conducted the studies. Thematic [“conceptual categories”] A thematic literature review is the most common approach to summarizing prior research in the social and behavioral sciences. Thematic reviews are organized around a topic or issue, rather than the progression of time, although the progression of time may still be incorporated into a thematic review. For example, a review of the Internet’s impact on American presidential politics could focus on the development of online political satire. While the study focuses on one topic, the Internet’s impact on American presidential politics, it would still be organized chronologically reflecting technological developments in media. The difference in this example between a "chronological" and a "thematic" approach is what is emphasized the most: themes related to the role of the Internet in presidential politics. Note that more authentic thematic reviews tend to break away from chronological order. A review organized in this manner would shift between time periods within each section according to the point being made. Methodological A methodological approach focuses on the methods utilized by the researcher. For the Internet in American presidential politics project, one methodological approach would be to look at cultural differences between the portrayal of American presidents on American, British, and French websites. Or the review might focus on the fundraising impact of the Internet on a particular political party. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed.

Other Sections of Your Literature Review Once you've decided on the organizational method for your literature review, the sections you need to include in the paper should be easy to figure out because they arise from your organizational strategy. In other words, a chronological review would have subsections for each vital time period; a thematic review would have subtopics based upon factors that relate to the theme or issue. However, sometimes you may need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you. However, only include what is necessary for the reader to locate your study within the larger scholarship about the research problem.

Here are examples of other sections, usually in the form of a single paragraph, you may need to include depending on the type of review you write:

• Current Situation : Information necessary to understand the current topic or focus of the literature review.
• Sources Used : Describes the methods and resources [e.g., databases] you used to identify the literature you reviewed.
• History : The chronological progression of the field, the research literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
• Selection Methods : Criteria you used to select (and perhaps exclude) sources in your literature review. For instance, you might explain that your review includes only peer-reviewed [i.e., scholarly] sources.
• Standards : Description of the way in which you present your information.
• Questions for Further Research : What questions about the field has the review sparked? How will you further your research as a result of the review?

IV.  Writing Your Literature Review

Once you've settled on how to organize your literature review, you're ready to write each section. When writing your review, keep in mind these issues.

Use Evidence A literature review section is, in this sense, just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence [citations] that demonstrates that what you are saying is valid. Be Selective Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the research problem, whether it is thematic, methodological, or chronological. Related items that provide additional information, but that are not key to understanding the research problem, can be included in a list of further readings . Use Quotes Sparingly Some short quotes are appropriate if you want to emphasize a point, or if what an author stated cannot be easily paraphrased. Sometimes you may need to quote certain terminology that was coined by the author, is not common knowledge, or taken directly from the study. Do not use extensive quotes as a substitute for using your own words in reviewing the literature. Summarize and Synthesize Remember to summarize and synthesize your sources within each thematic paragraph as well as throughout the review. Recapitulate important features of a research study, but then synthesize it by rephrasing the study's significance and relating it to your own work and the work of others. Keep Your Own Voice While the literature review presents others' ideas, your voice [the writer's] should remain front and center. For example, weave references to other sources into what you are writing but maintain your own voice by starting and ending the paragraph with your own ideas and wording. Use Caution When Paraphrasing When paraphrasing a source that is not your own, be sure to represent the author's information or opinions accurately and in your own words. Even when paraphrasing an author’s work, you still must provide a citation to that work.

V.  Common Mistakes to Avoid

These are the most common mistakes made in reviewing social science research literature.

• Sources in your literature review do not clearly relate to the research problem;
• You do not take sufficient time to define and identify the most relevant sources to use in the literature review related to the research problem;
• Relies exclusively on secondary analytical sources rather than including relevant primary research studies or data;
• Uncritically accepts another researcher's findings and interpretations as valid, rather than examining critically all aspects of the research design and analysis;
• Does not describe the search procedures that were used in identifying the literature to review;
• Reports isolated statistical results rather than synthesizing them in chi-squared or meta-analytic methods; and,
• Only includes research that validates assumptions and does not consider contrary findings and alternative interpretations found in the literature.

Cook, Kathleen E. and Elise Murowchick. “Do Literature Review Skills Transfer from One Course to Another?” Psychology Learning and Teaching 13 (March 2014): 3-11; Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . London: SAGE, 2011; Literature Review Handout. Online Writing Center. Liberty University; Literature Reviews. The Writing Center. University of North Carolina; Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: SAGE, 2016; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012; Randolph, Justus J. “A Guide to Writing the Dissertation Literature Review." Practical Assessment, Research, and Evaluation. vol. 14, June 2009; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016; Taylor, Dena. The Literature Review: A Few Tips On Conducting It. University College Writing Centre. University of Toronto; Writing a Literature Review. Academic Skills Centre. University of Canberra.

Writing Tip

Break Out of Your Disciplinary Box!

Thinking interdisciplinarily about a research problem can be a rewarding exercise in applying new ideas, theories, or concepts to an old problem. For example, what might cultural anthropologists say about the continuing conflict in the Middle East? In what ways might geographers view the need for better distribution of social service agencies in large cities than how social workers might study the issue? You don’t want to substitute a thorough review of core research literature in your discipline for studies conducted in other fields of study. However, particularly in the social sciences, thinking about research problems from multiple vectors is a key strategy for finding new solutions to a problem or gaining a new perspective. Consult with a librarian about identifying research databases in other disciplines; almost every field of study has at least one comprehensive database devoted to indexing its research literature.

Frodeman, Robert. The Oxford Handbook of Interdisciplinarity . New York: Oxford University Press, 2010.

Another Writing Tip

Don't Just Review for Content!

While conducting a review of the literature, maximize the time you devote to writing this part of your paper by thinking broadly about what you should be looking for and evaluating. Review not just what scholars are saying, but how are they saying it. Some questions to ask:

• How are they organizing their ideas?
• What methods have they used to study the problem?
• What theories have been used to explain, predict, or understand their research problem?
• What sources have they cited to support their conclusions?
• How have they used non-textual elements [e.g., charts, graphs, figures, etc.] to illustrate key points?

When you begin to write your literature review section, you'll be glad you dug deeper into how the research was designed and constructed because it establishes a means for developing more substantial analysis and interpretation of the research problem.

Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1 998.

Yet Another Writing Tip

When Do I Know I Can Stop Looking and Move On?

Here are several strategies you can utilize to assess whether you've thoroughly reviewed the literature:

• Look for repeating patterns in the research findings . If the same thing is being said, just by different people, then this likely demonstrates that the research problem has hit a conceptual dead end. At this point consider: Does your study extend current research?  Does it forge a new path? Or, does is merely add more of the same thing being said?
• Look at sources the authors cite to in their work . If you begin to see the same researchers cited again and again, then this is often an indication that no new ideas have been generated to address the research problem.
• Search Google Scholar to identify who has subsequently cited leading scholars already identified in your literature review [see next sub-tab]. This is called citation tracking and there are a number of sources that can help you identify who has cited whom, particularly scholars from outside of your discipline. Here again, if the same authors are being cited again and again, this may indicate no new literature has been written on the topic.

Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: Sage, 2016; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

• << Previous: Theoretical Framework
• Next: Citation Tracking >>
• Last Updated: Apr 11, 2024 1:27 PM
• URL: https://libguides.usc.edu/writingguide

What Is A Literature Review?

A plain-language explainer (with examples).

By:  Derek Jansen (MBA) & Kerryn Warren (PhD) | June 2020 (Updated May 2023)

If you’re faced with writing a dissertation or thesis, chances are you’ve encountered the term “literature review” . If you’re on this page, you’re probably not 100% what the literature review is all about. The good news is that you’ve come to the right place.

Literature Review 101

• What (exactly) is a literature review
• What’s the purpose of the literature review chapter
• How to find high-quality resources
• How to structure your literature review chapter
• Example of an actual literature review

What is a literature review?

The word “literature review” can refer to two related things that are part of the broader literature review process. The first is the task of  reviewing the literature  – i.e. sourcing and reading through the existing research relating to your research topic. The second is the  actual chapter  that you write up in your dissertation, thesis or research project. Let’s look at each of them:

Reviewing the literature

The first step of any literature review is to hunt down and  read through the existing research  that’s relevant to your research topic. To do this, you’ll use a combination of tools (we’ll discuss some of these later) to find journal articles, books, ebooks, research reports, dissertations, theses and any other credible sources of information that relate to your topic. You’ll then  summarise and catalogue these  for easy reference when you write up your literature review chapter. 

The literature review chapter

The second step of the literature review is to write the actual literature review chapter (this is usually the second chapter in a typical dissertation or thesis structure ). At the simplest level, the literature review chapter is an  overview of the key literature  that’s relevant to your research topic. This chapter should provide a smooth-flowing discussion of what research has already been done, what is known, what is unknown and what is contested in relation to your research topic. So, you can think of it as an  integrated review of the state of knowledge  around your research topic. 

What’s the purpose of a literature review?

The literature review chapter has a few important functions within your dissertation, thesis or research project. Let’s take a look at these:

Purpose #1 – Demonstrate your topic knowledge

The first function of the literature review chapter is, quite simply, to show the reader (or marker) that you  know what you’re talking about . In other words, a good literature review chapter demonstrates that you’ve read the relevant existing research and understand what’s going on – who’s said what, what’s agreed upon, disagreed upon and so on. This needs to be  more than just a summary  of who said what – it needs to integrate the existing research to  show how it all fits together  and what’s missing (which leads us to purpose #2, next). 

Purpose #2 – Reveal the research gap that you’ll fill

The second function of the literature review chapter is to  show what’s currently missing  from the existing research, to lay the foundation for your own research topic. In other words, your literature review chapter needs to show that there are currently “missing pieces” in terms of the bigger puzzle, and that  your study will fill one of those research gaps . By doing this, you are showing that your research topic is original and will help contribute to the body of knowledge. In other words, the literature review helps justify your research topic.  

Purpose #3 – Lay the foundation for your conceptual framework

The third function of the literature review is to form the  basis for a conceptual framework . Not every research topic will necessarily have a conceptual framework, but if your topic does require one, it needs to be rooted in your literature review. 

For example, let’s say your research aims to identify the drivers of a certain outcome – the factors which contribute to burnout in office workers. In this case, you’d likely develop a conceptual framework which details the potential factors (e.g. long hours, excessive stress, etc), as well as the outcome (burnout). Those factors would need to emerge from the literature review chapter – they can’t just come from your gut! 

So, in this case, the literature review chapter would uncover each of the potential factors (based on previous studies about burnout), which would then be modelled into a framework. 

Purpose #4 – To inform your methodology

The fourth function of the literature review is to  inform the choice of methodology  for your own research. As we’ve  discussed on the Grad Coach blog , your choice of methodology will be heavily influenced by your research aims, objectives and questions . Given that you’ll be reviewing studies covering a topic close to yours, it makes sense that you could learn a lot from their (well-considered) methodologies.

So, when you’re reviewing the literature, you’ll need to  pay close attention to the research design , methodology and methods used in similar studies, and use these to inform your methodology. Quite often, you’ll be able to  “borrow” from previous studies . This is especially true for quantitative studies , as you can use previously tried and tested measures and scales. 

How do I find articles for my literature review?

Finding quality journal articles is essential to crafting a rock-solid literature review. As you probably already know, not all research is created equally, and so you need to make sure that your literature review is  built on credible research . 

We could write an entire post on how to find quality literature (actually, we have ), but a good starting point is Google Scholar . Google Scholar is essentially the academic equivalent of Google, using Google’s powerful search capabilities to find relevant journal articles and reports. It certainly doesn’t cover every possible resource, but it’s a very useful way to get started on your literature review journey, as it will very quickly give you a good indication of what the  most popular pieces of research  are in your field.

One downside of Google Scholar is that it’s merely a search engine – that is, it lists the articles, but oftentimes  it doesn’t host the articles . So you’ll often hit a paywall when clicking through to journal websites. 

Thankfully, your university should provide you with access to their library, so you can find the article titles using Google Scholar and then search for them by name in your university’s online library. Your university may also provide you with access to  ResearchGate , which is another great source for existing research. 

Remember, the correct search keywords will be super important to get the right information from the start. So, pay close attention to the keywords used in the journal articles you read and use those keywords to search for more articles. If you can’t find a spoon in the kitchen, you haven’t looked in the right drawer. 

Need a helping hand?

How should I structure my literature review?

Unfortunately, there’s no generic universal answer for this one. The structure of your literature review will depend largely on your topic area and your research aims and objectives.

You could potentially structure your literature review chapter according to theme, group, variables , chronologically or per concepts in your field of research. We explain the main approaches to structuring your literature review here . You can also download a copy of our free literature review template to help you establish an initial structure.

In general, it’s also a good idea to start wide (i.e. the big-picture-level) and then narrow down, ending your literature review close to your research questions . However, there’s no universal one “right way” to structure your literature review. The most important thing is not to discuss your sources one after the other like a list – as we touched on earlier, your literature review needs to synthesise the research , not summarise it .

Ultimately, you need to craft your literature review so that it conveys the most important information effectively – it needs to tell a logical story in a digestible way. It’s no use starting off with highly technical terms and then only explaining what these terms mean later. Always assume your reader is not a subject matter expert and hold their hand through a journe y of the literature while keeping the functions of the literature review chapter (which we discussed earlier) front of mind.

Example of a literature review

In the video below, we walk you through a high-quality literature review from a dissertation that earned full distinction. This will give you a clearer view of what a strong literature review looks like in practice and hopefully provide some inspiration for your own. 

Wrapping Up

In this post, we’ve (hopefully) answered the question, “ what is a literature review? “. We’ve also considered the purpose and functions of the literature review, as well as how to find literature and how to structure the literature review chapter. If you’re keen to learn more, check out the literature review section of the Grad Coach blog , as well as our detailed video post covering how to write a literature review . 

Psst… there’s more!

This post is an extract from our bestselling Udemy Course, Literature Review Bootcamp . If you want to work smart, you don't want to miss this .

You Might Also Like:

16 Comments

Thanks for this review. It narrates what’s not been taught as tutors are always in a early to finish their classes.

Thanks for the kind words, Becky. Good luck with your literature review 🙂

This website is amazing, it really helps break everything down. Thank you, I would have been lost without it.

This is review is amazing. I benefited from it a lot and hope others visiting this website will benefit too.

Timothy T. Chol [email protected]

Thank you very much for the guiding in literature review I learn and benefited a lot this make my journey smooth I’ll recommend this site to my friends

This was so useful. Thank you so much.

Hi, Concept was explained nicely by both of you. Thanks a lot for sharing it. It will surely help research scholars to start their Research Journey.

The review is really helpful to me especially during this period of covid-19 pandemic when most universities in my country only offer online classes. Great stuff

Great Brief Explanation, thanks

So helpful to me as a student

GradCoach is a fantastic site with brilliant and modern minds behind it.. I spent weeks decoding the substantial academic Jargon and grounding my initial steps on the research process, which could be shortened to a couple of days through the Gradcoach. Thanks again!

This is an amazing talk. I paved way for myself as a researcher. Thank you GradCoach!

Well-presented overview of the literature!

This was brilliant. So clear. Thank you

Submit a Comment Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

• Print Friendly

Why is it important to do a literature review in research?

The importance of scientific communication in the healthcare industry

The Importance and Role of Biostatistics in Clinical Research

 “A substantive, thorough, sophisticated literature review is a precondition for doing substantive, thorough, sophisticated research”. Boote and Baile 2005

Authors of manuscripts treat writing a literature review as a routine work or a mere formality. But a seasoned one knows the purpose and importance of a well-written literature review.  Since it is one of the basic needs for researches at any level, they have to be done vigilantly. Only then the reader will know that the basics of research have not been neglected.

The aim of any literature review is to summarize and synthesize the arguments and ideas of existing knowledge in a particular field without adding any new contributions.   Being built on existing knowledge they help the researcher to even turn the wheels of the topic of research.  It is possible only with profound knowledge of what is wrong in the existing findings in detail to overpower them.  For other researches, the literature review gives the direction to be headed for its success. 

The common perception of literature review and reality:

As per the common belief, literature reviews are only a summary of the sources related to the research. And many authors of scientific manuscripts believe that they are only surveys of what are the researches are done on the chosen topic.  But on the contrary, it uses published information from pertinent and relevant sources like

• Scholarly books
• Scientific papers
• Latest studies in the field
• Established school of thoughts
• Relevant articles from renowned scientific journals

and many more for a field of study or theory or a particular problem to do the following:

• Summarize into a brief account of all information
• Synthesize the information by restructuring and reorganizing
• Critical evaluation of a concept or a school of thought or ideas
• Familiarize the authors to the extent of knowledge in the particular field
• Encapsulate
• Compare & contrast

By doing the above on the relevant information, it provides the reader of the scientific manuscript with the following for a better understanding of it:

• It establishes the authors’  in-depth understanding and knowledge of their field subject
• It gives the background of the research
• Portrays the scientific manuscript plan of examining the research result
• Illuminates on how the knowledge has changed within the field
• Highlights what has already been done in a particular field
• Information of the generally accepted facts, emerging and current state of the topic of research
• Identifies the research gap that is still unexplored or under-researched fields
• Demonstrates how the research fits within a larger field of study
• Provides an overview of the sources explored during the research of a particular topic

Importance of literature review in research:

The importance of literature review in scientific manuscripts can be condensed into an analytical feature to enable the multifold reach of its significance.  It adds value to the legitimacy of the research in many ways:

• Provides the interpretation of existing literature in light of updated developments in the field to help in establishing the consistency in knowledge and relevancy of existing materials
• It helps in calculating the impact of the latest information in the field by mapping their progress of knowledge.
• It brings out the dialects of contradictions between various thoughts within the field to establish facts
• The research gaps scrutinized initially are further explored to establish the latest facts of theories to add value to the field
• Indicates the current research place in the schema of a particular field
• Provides information for relevancy and coherency to check the research
• Apart from elucidating the continuance of knowledge, it also points out areas that require further investigation and thus aid as a starting point of any future research
• Justifies the research and sets up the research question
• Sets up a theoretical framework comprising the concepts and theories of the research upon which its success can be judged
• Helps to adopt a more appropriate methodology for the research by examining the strengths and weaknesses of existing research in the same field
• Increases the significance of the results by comparing it with the existing literature
• Provides a point of reference by writing the findings in the scientific manuscript
• Helps to get the due credit from the audience for having done the fact-finding and fact-checking mission in the scientific manuscripts
• The more the reference of relevant sources of it could increase more of its trustworthiness with the readers
• Helps to prevent plagiarism by tailoring and uniquely tweaking the scientific manuscript not to repeat other’s original idea
• By preventing plagiarism , it saves the scientific manuscript from rejection and thus also saves a lot of time and money
• Helps to evaluate, condense and synthesize gist in the author’s own words to sharpen the research focus
• Helps to compare and contrast to  show the originality and uniqueness of the research than that of the existing other researches
• Rationalizes the need for conducting the particular research in a specified field
• Helps to collect data accurately for allowing any new methodology of research than the existing ones
• Enables the readers of the manuscript to answer the following questions of its readers for its better chances for publication
• What do the researchers know?
• What do they not know?
• Is the scientific manuscript reliable and trustworthy?
• What are the knowledge gaps of the researcher?

22. It helps the readers to identify the following for further reading of the scientific manuscript:

• What has been already established, discredited and accepted in the particular field of research
• Areas of controversy and conflicts among different schools of thought
• Unsolved problems and issues in the connected field of research
• The emerging trends and approaches
• How the research extends, builds upon and leaves behind from the previous research

A profound literature review with many relevant sources of reference will enhance the chances of the scientific manuscript publication in renowned and reputed scientific journals .

References:

http://www.math.montana.edu/jobo/phdprep/phd6.pdf

journal Publishing services  |  Scientific Editing Services  |  Medical Writing Services  |  scientific research writing service  |  Scientific communication services

Related Topics:

Meta Analysis

Scientific Research Paper Writing

Medical Research Paper Writing

Scientific Communication in healthcare

pubrica academy

Related posts.

Statistical analyses of case-control studies

PUB - Selecting material (e.g. excipient, active pharmaceutical ingredient) for drug development

Selecting material (e.g. excipient, active pharmaceutical ingredient, packaging material) for drug development

PUB - Health Economics of Data Modeling

Health economics in clinical trials

Comments are closed.

• SUGGESTED TOPICS
• The Magazine
• Newsletters
• Managing Yourself
• Managing Teams
• Work-life Balance
• The Big Idea
• Data & Visuals
• Reading Lists
• Case Selections
• HBR Learning
• Topic Feeds
• Account Settings
• Email Preferences

What Needs to Change About DEI — and What Doesn’t

As DEI faces social, political, and legal backlash, leaders need to take stock of their efforts.

As DEI work faces increasing scrutiny socially, politically, and legally, organizations are taking extra care to re-evaluate their DEI efforts. Leaders are right to consider change, not as a reaction to backlash, but to work toward a more accountable, transparent, and successful vision of what DEI could be. The author identifies three things that need to change: 1) Clumsy, jargon-heavy communication, 2) disconnected and decoupled DEI goals and programs, and 3) nonexistent or vanity DEI measurement. They also identify three things that should be maintained: 1) Responsiveness to broader society, 2) commitment to healthy organizations, and 3) the belief that we can be better.

Organizations and their leaders have endeavored to create more diverse, equitable, and inclusive organizations in one way or another since the mid-1960s , even as the sociopolitical climate around these efforts has fluctuated.

• Lily Zheng  is a diversity, equity, and inclusion strategist, consultant, and speaker   who works with organizations to achieve the DEI impact and outcomes they need.   They are the author of DEI Deconstructed: Your No-Nonsense Guide to Doing the Work and Doing it Right. 

Partner Center

• Case Report
• Open access
• Published: 06 April 2024

Super-refractory status epilepticus, rhabdomyolysis, central hyperthermia and cardiomyopathy attributable to spinal anesthesia: a case report and review of literature

• N. D.B. Ehelepola   ORCID: orcid.org/0000-0001-9133-2307 1 ,
• R. M.D.C. Ranathunga 1 ,
• A. B. Abeysundara 1 , 2 ,
• H. M.R.P. Jayawardana 1 &
• P. S.K. Nanayakkara 1 , 2  

BMC Anesthesiology volume  24 , Article number:  132 ( 2024 ) Cite this article

234 Accesses

Metrics details

There are only six past reports of super-refractory status epilepticus induced by spinal anesthesia. None of those patients have died. Only < 15 mg of bupivacaine was administered to all six of them and to our case. Pathophysiology ensuing such cases remains unclear.

Case presentation

A 27 year old gravida 2, para 1, mother at 37 weeks of gestation came to the operating theater for an elective cesarean section. She had no significant medical history other than controlled hypothyroidism and one episode of food allergy. Her current pregnancy was uneventful. Her American Society of Anesthesiologists (ASA) grade was 2. She underwent spinal anesthesia and adequate anesthesia was achieved. After 5–7 min she developed a progressive myoclonus. After delivery of a healthy baby, she developed generalized tonic clonic seizures that continued despite the induction of general anesthesia. She had rhabdomyolysis, one brief cardiac arrest and resuscitation, followed by stress cardiomyopathy and central hyperthermia. She died on day four. There were no significant macroscopic or histopathological changes in her brain that explain her super refractory status epilepticus. Heavy bupivacaine samples of the same batch used for this patient were analyzed by two specialized laboratories. National Medicines Quality Assurance Laboratory of Sri Lanka reported that samples failed to confirm United States Pharmacopeia (USP) dextrose specifications and passed other tests. Subsequently, Therapeutic Goods Administration of Australia reported that the drug passed all standard USP quality tests applied to it. Nonetheless, they have detected an unidentified impurity in the medicine.

Conclusions

After reviewing relevant literature, we believe that direct neurotoxicity by bupivacaine is the most probable cause of super-refractory status epilepticus. Super-refractory status epilepticus would have led to her other complications and death. We discuss probable patient factors that would have made her susceptible to neurotoxicity. The impurity in the drug detected by one laboratory also would have contributed to her status epilepticus. We propose several possible mechanisms that would have led to status epilepticus and her death. We discuss the factors that shall guide investigators on future such cases. We suggest ways to minimize similar future incidents. This is an idiosyncratic reaction as well.

Graphical Abstract

Peer Review reports

There are only a few past reports on status epilepticus attributed to drugs used for spinal anesthesia [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Out of those, six past reports are of super-refractory status epilepticus cases attributed to bupivacaine and those patients have recovered [ 1 , 2 , 3 , 4 , 5 , 6 ]. Pathophysiology resulting in such cases notwithstanding only < 15 mg of bupivacaine administered, remains unclear. A status epilepticus that continues for ≥ 24 h despite anesthetic treatment, or recurs on an attempted wean of the anesthetic drugs is defined as super-refractory status epilepticus [ 5 , 8 ]. There are no past reports of the combination of super-refractory status epilepticus, rhabdomyolysis, central hyperthermia and cardiomyopathy resulting in the death of a previously healthy person attributed to a spinal anesthetic agent. This death and a few other subsequent deaths due to drug side effects and the alleged poor quality of the responsible drugs generated a huge outcry in most national news media. Many social media sensationalized the issue and it was debated in Sri Lanka’s parliament as well. That resulted in anxiety among patients undergoing anesthesia, anesthesiology doctors and people utilizing public hospitals. There were some public protests in Sri Lanka in 2023 regarding this issue. This crisis was in the news in some other countries as well [ 9 ].

A 27 year old pregnant woman, height 151 cm, weight 78 kg (Body Mass Index 34.2), in 37 weeks of gestation, came to the operating theater for an elective cesarean section (EL/LSCS) after routine preparation. She is the mother of a five year old child and this is her second pregnancy. Other than hypothyroidism controlled with thyroxin for the past three months she had no significant medical history or history of substance abuse. However, after the below mentioned incident her father told doctors that she had one allergic reaction to pineapple during her childhood which did not require hospital care. Therefore, her ASA grade was 2. She underwent spinal anesthesia in the sitting position, lumbar 4–5 level. A 25G pencil point needle was used. After verification, 2.5 cc of 0.5% heavy bupivacaine = 12.5 mg of bupivacaine (ZUPIVAC H, batch No.DP2203) without adjuvants was administered. Adequate analgesia was achieved up to thoracic dermatome7 level and surgery was started. After 5–7 min, she complained of a backache and a “discomfort” which she could not explain. Then she developed occasional myoclonus in her upper limbs and upper trunk and that once involved legs as well. Myoclonus was momentarily controlled by 2 mg of intravenous (IV) midazolam. Myoclonus progressed in magnitude and frequency. When asked, she denied any circumoral numbness and power of the grip of her both hands was normal. A crying baby was delivered 10 min after anesthesia. Oxytocin was administered and the mother could verbally communicate with the medical officer-anesthesiology. Then her eyes deviated upwards, she could not respond verbally and developed generalized tonic clonic seizures (GTCS). General anesthesia was inducted using thiopentone, she was intubated with suxamethonium and ventilated. Her blood pressure remained 130/80 mmHg − 140/90 mmHg, heart rate in 110–140/min range, ECG(EKG) showed sinus tachycardia, and her peripheries were warm and flushed. ETCO 2 was 55–65 mmHg. Her both pupils were 3 mm and sluggishly reacting to light. Her random blood sugar level was 134 mg/dl. As she developed some bilateral rhonchi (lungs), intravenous (IV) hydrocortisone, chlorpheniramine was administered and she was nebulized with ipratropium. There was uterine atony and bleeding. IV oxyticin, intramuscular ergometrin and per rectal misoprostol were administered and one unit of blood was transfused. Two and a half hours after anesthesia she was taken to the ICU and electively ventilated. Her arterial blood pH was 7.03 and her lactate level was 9.6 mmol/l. Acidosis was corrected with IV sodium bicarbonate. Her chest X ray (CXR) showed a globular heart and haziness in the left lung field, NCCT did not show any abnormality in the brain, protein was +++ in urine; and there was no proteinuria before surgery (many public hospital laboratories of Sri Lanka report proteinuria in a scale from trace to +++. Three + means very high levels). She developed hypotension and norepinephrine infusion was started at 0.3 µg/kg/min rate. She was assessed by consultants/professors in anesthesiology, obstetrics, internal medicine and neurology and by other doctors on the same day. The differential diagnoses of the multi-disciplinary team were an adverse reaction to bupivacaine, amniotic fluid embolism, normotensive eclampsia and previously undiagnosed brain pathology. Our primary goal was to control her seizures while providing life support therapy. She was administered thiopentone, midazolam, MgSO4, levetiracetam, morphine, mannitol and antibiotics etc. Approximately once in four hours thiopentone infusion was withheld to assess her for seizures and to avoid myocardial depression. Atracurium was administered as 25 mg boluses. Whenever the effect of atracurium was weaning she had continuous GTCS on days 1–3 sometimes even while thiopentone was being infused. 20% fat emulsion was not available at our and nearby hospitals at that period of time. Her ETCO 2 remained in 34 -40mmHg range after admission to the ICU.

On the following morning (day 2) she had an episode of bradycardia followed by cardiac arrest and was successfully resuscitated within five minutes. Epinephrine and dopamine infusions were added after this. A 2D echocardiogram performed by one of the ICU doctors did not show hypokinesia in the ventricular walls. Her tachycardia persisted and she developed fever spikes. ST elevations appeared in lead 1, aVL of the ECG(EKG). Therefore, aspirin, clopidogrel and atorvastatin were added. Status epilepticus continued thus levetiracetam dose was increased, IV phenytoin and NG lacosamide were added.

On day3,the seizure frequency decreased. Repeated NCCT did not show any hemorrhages or infarcts in the brain. ST elevations were seen in leads I, aVL, V5-V6 in ECG and troponin I was > 50 ng/ml. Hence, cardiologists opinion was obtained. Creatine kinase (CK) level was 21,420 U/L and alkaline diuresis was started. She had two high fever spikes per day, each > 40 0 C on day 2 and day3.

On day 4, she was seizure free but had hyperpyrexia (once 42.8 0 C) despite active cooling. Lumbar puncture was done and CSF analysis did not show evidence of infection. Same morning she suffered a cardiac arrest, resuscitation was continued for more than an hour but was unsuccessful.

After the drop in day 2, her blood pressure was maintained with three inotropes infused at the following rates. Norepinephrine at 0.3–0.6 µg/kg/min, epinephrine at 0.3–0.6 µg/kg/min and dopamine at 20 − 10 µg/kg/min. Her SpO 2 remained > 92%, her urine output was 40-100 ml/hour and serum creatinine levels were 87–123 micromoles/l during her ICU stay. Her day 1 prothrombin time was 19.2 s and INR was 1.62. Thiopentone would have contributed to this prolongation of INR [ 10 ]. INR was ≤ 1.5 after day 2. Her activated partial thromboplastin time was 26.5 s on day1 and remained normal. EEG and MRI brain could not be done before her death.

The autopsy was performed by a consultant judicial medical officer. Both lungs were congested and exuded frothy fluid on sectioning and the liver was enlarged and soft. No other remarkable abnormalities were detected including in the brain and heart. However, spinal cord was not dissected.

Cerebrum and cerebellum histopathology were unremarkable. Widespread early ischemic changes were seen in the myocardium. Centrilobular necrosis with occasional bridging necrosis in 20% of the liver and mild acute tubular necrosis in the kidneys were seen. Extensive degenerative changes were seen in skeletal muscles. Pulmonary edema, evidence of mild pneumonia and focal hemorrhages were seen in the lungs. Multiple bone marrow emboli were seen in the lungs and heart, consistent with changes associated with prolonged CPR. All changes seen were acute changes.

Samples from all three batches of ZUPIVAC H at our hospital were analyzed by the National Medicines Quality Assurance Laboratory (NMQAL) of Sri Lanka. Samples confirmed USP bupivacaine and other specifications but batch No.s DP 2203 and DP 2202 failed to confirm dextrose specifications. Thereafter, samples were re-analyzed at the Therapeutic Goods Administration (TGA) laboratories of the Australian government. When batch No. DP 2203 was tested according to the relevant USP monograph to validate the medicine and its ingredients, the medicine passed the tests applied to it (it passed the quality test). However, there is no impurity test in the USP monograph. Considering the very unusual and lethal nature of this adverse drug reaction we have requested TGA-Australia look for any impurities as well. Fulfilling our request, they have identified an impurity that is suspected to be structurally related to bupivacaine in batch No. DP 2203. It’s content was estimated to be 0.9% relative to bupivacaine. They have confirmed that this impurity is not mepivacaine. This impurity was not specifically identified in any of the pharmacopoeias available at TGA-Australia. Despite further testing, they were unable to identify what exactly this impurity is. TGA-Australia has noticed another unusual thing. That is although the ZUPIVAC H label claims compliance with the USP for the finished product, they claim compliance with the Indian Pharmacopoeia (IP) for raw materials. The full report is given as a supplementary file.

Discussion and conclusions

Our discussion has eight subheadings. Those are; key facts of the case report, how did we conducted a systematic literature review to find similar reported cases, the relationship of the presented case with the existing literature, circumstantial evidence for and against suspecting heavy bupivacaine (ZUPIVAC H) as the cause of her seizures, explanation of the patient’s clinical and autopsy findings, differential diagnoses we considered at different stages, discussion of central nervous system toxicity by bupivacaine and possible mechanisms of toxicity and lessons to be learned and the way forward.

Key facts of the case report

An ASA grade 2 pregnant mother underwent a routine a spinal anesthesia for a cesarean section and adequate anesthesia was achieved. After 5–7 min, she developed a progressive myoclonus that evolved into generalized tonic clonic seizures after delivery. Her seizures continued despite administering general anesthesia plus multiple anticonvulsants. She had rhabdomyolysis, one brief cardiac arrest, stress cardiomyopathy, central hyperthermia and died on day four. There were no significant radiological, macroscopic or histopathological changes in her brain or biochemical changes that explained her super refractory status epilepticus. Heavy bupivacaine samples from the same batch used for this patient were analyzed by two specialized laboratories. One laboratory reported that samples failed to confirm USP dextrose specifications. Bupivacaine samples passed all standard USP quality tests at the other laboratory. Nevertheless, they managed to detect an unidentified impurity in the medicine.

How did we conducted a systematic literature review to find similar reported cases

Super-refractory status epilepticus is rare and many doctors we know do not use that term. Thus, we decided to search for the word “status epilepticus” and select super-refractory status epilepticus cases out of those. We conducted a literature survey in several online databases in February 2024 for the keywords “status epilepticus”,“spinal anesthesia” and “case report” combined using the Boolean operator “AND”. Those databases were Google Scholar, PubMed, Europe PubMed Central, CNKI, ScienceDirect and DOAJ. A total of 576 articles were identified. Abstracts of each were read and 564 irrelevant articles were excluded. We used the PICO (P: patient/population/problem, I: intervention, C: comparison/control—O: outcome) framework to determine inclusion criteria [ 11 ]. Accordingly, we selected patients undergoing spinal anesthesia as our population, spinal anesthesia as intervention and super-refractory status epilepticus cases as the outcome. Out of the remaining 12, duplicates were removed, full articles were read and five cases that fulfill the definition of super-refractory status epilepticus attributed to a spinal anesthesia drug were identified. They were our references 2,3,5 and 6. The snowballing of those led to identification of our reference1. First and third authors independently did this process and obtained the same results.

The flowchart of the process is shown in Fig.  1 .

The flowchart of systematic literature review process

In cases of reference1 and 6 the duration of seizures was not clearly mentioned, but their authors state that seizures continued despite the administering of anesthetic drugs. Super-refractory status epilepticus is primarily defined by failure to respond to appropriate treatment, not by seizure duration [ 12 ]. Hence, we included those two cases. The case of reference 7 has seizures for a few hours; hence we did not include that. Nonetheless, it is the first report (1994) of a status epilepticus (refractory status epilepticus) case following spinal anesthesia we found [ 7 ]. That patient had a history of seizures and tertracaine was used for anesthesia.

Earlier, we did a nonsystematic literature survey employing various strings. Among results for the string “local anesthetic systemic toxicity” AND “case reports” we have identified our reference 4. Key findings from past six reports of super-refractory status epilepticus attributable to spinal anesthesia are summarized in Table  1 . The authors of some of those papers do not classify their cases as super-refractory status epilepticus cases.

Relationship of the presented case with the existing literature

Similar to our case, all six cases were anesthetized using heavy bupivacaine. Only < 15 mg of bupivacaine was administered to all of them. However, sufentanil was added to heavy bupivacaine in two cases unlike us. None of them or our patient had any history of past seizures. Interestingly, 5/6 patients were women. Three past cases like our patient, had seizures minutes after spinal anesthesia while undergoing cesarean sections. One of them had a history of preeclampsia unlike our case. 3/6 had discomfort in the perineum or coccyx region before seizures and our patient complained of a discomfort that she could not describe. Like in our case, 3/6 had myoclonus or tremors prior to seizures. All past cases survived. None of the past cases had the combination of rhabdomyolysis, a brief cardiac arrest followed by stress cardiomyopathy and central hyperthermia.

There are several other reports of seizures associated with spinal anesthesia [ 3 , 13 , 14 , 15 ]. Only two cases of seizures following spinal anesthesia was reported between 1945 and 1962 according to one author [ 13 ]. Reports have become more frequent lately (Table  1 ). A recent paper summarized 30 publications describing 31 patients and two cats who had had GTCS or myoclonus following spinal anesthesia [ 15 ]. Out of those cases, 64% resolved spontaneously and promptly and in 71% of cases neurotoxicity manifested 30 min after spinal anesthesia, in contrast to our case [ 15 ]. In the literature, there is a spectrum of cases varying from mild self-limiting myoclonus probably originating at the spinal cord level, to super-refractory status epilepticus cases like our case. We think the likely explanation for our case as follows. Initially, she would have had spinal myoclonus which was momentarily controlled by Midazolam. Although its density was higher than that of the CSF (as explained later), a minute fraction of administered ZUPIVAC H would have gradually reached the brain due to movement of cerebrospinal fluid and diffusion [ 16 ]. Then the drug acting on the brain would have initiated GTCS.

Circumstantial evidence for and against suspecting heavy bupivacaine (ZUPIVAC H) as the cause of her seizures

Our hospital uses about 400–450 ampoules of heavy bupivacaine per month at present. No similar incident happened at our hospital during the past 23 years to our knowledge. ZUPIVAC H brand arrived at our hospital for the first time, 45 days before this incident. Ampoules of batch No. DP2203 arrived at our hospital eight days before this incident. Another patient in our hospital developed refractory status epilepticus to ZUPIVAC H three days apart, arousing suspicion of something unique to ZUPIVAC H contributing to these events. Moreover, our patient had undergone spinal anesthesia with heavy bupivacaine (without adjuvants) five years before for her first LSCS, without complications. Therefore, we suspect that the impurity in the drug also contributed to her seizures. Nevertheless, there are reports of patients who had undergone uneventful spinal anesthesia, developing neurotoxicity during subsequent spinal anesthesia [ 15 , 17 ]. Forty five patients in our hospital and more patients in other hospitals have undergone spinal anesthesia with ZUPIVAC H of the same batch without a problem on the same day and within the previous seven days. That fact is against suspecting a factor unique to ZUPIVAC H causing this event. Considering all this, we believe that ZUPIVAC H was the likely reason for her side effects and certain patient factors would have made our patient and the other patient of our hospital susceptible to the side effects of ZUPIVAC H.

Explanation of the patient’s clinical and autopsy findings

Rapid onset of high fever, marked temperature fluctuations ending in death usually occur in central hyperthermia [ 18 ]. We think she had central hyperthermia owing to brain damage due to super-refractory status epilepticus plus possibly due to ZUPIVAC H [ 19 , 20 , 21 ]. Heat generated in muscles during seizures would have contributed to her fever initially, but when her temperature was highest (day 4) there were no seizures. High fever notwithstanding antipyretics and antibiotics, decline in CRP level from day 2 to day 4, normal CSF analysis results and negative central venous catheter blood and urine culture results indicate that infection is unlikely to be the cause of her hyperpyrexia. However, her neutrophil count was very high on day1 but gradually dropped. Her high neutrophil counts can be attributed to status epilepticus [ 20 ].

Neurocardiogenic pulmonary edema following status epilepticus is well documented [ 20 , 21 ]. That explains her first day CXR changes. Our patient had a cardiac arrest on day 2 and resuscitated and on day 4 undergone a prolonged (> 1 h) cardiopulmonary resuscitation (CPR) before her death was confirmed. Respiratory tract infections (pneumonia) is the most common infection associated with status epilepticus [ 20 ].Those would have contributed to the changes in lungs observed at autopsy [ 20 , 21 , 22 ].

Rhabdomyolysis following status epilepticus is common and well known [ 20 , 21 ]. Some drugs given to her like phenytoin and levetiracetam and pre-existing hypothyroidism may have aggravated rhabdomyolysis [ 23 , 24 ].

Sudden unexpected cardiac arrest and death can happen in uncontrolled epilepsy [ 25 ]. Her cardiac arrest on day 2 may be attributable to status epilepticus [ 25 ]. The combination of effects of infused thiopentone and any bupivacaine cardiotoxicity also may have contributed to this. Although the echocardiogram did not depict characteristic left ventricular apical akinesia and ballooning, considering ST elevations in her ECG that appeared after doing the echocardiogram, very high troponin I levels and no blocks in coronaries observed at autopsy we think she may have had Takotsubo cardiomyopathy (stress cardiomyopathy) later. The stress of severe illness, first cardiac arrest and being on three inotropes also would have contributed to this. About 50 Takotsubo cardiomyopathy cases have been reported related to seizure activity, including 15 associated with status epilepticus [ 26 ]. Interestingly, there are reports of ischemic ECG changes, elevated troponin I with normal coronary angiography without seizures resulting after spinal anesthesia described as bupivacaine induced cardiac toxicity by reporting authors [ 27 , 28 ].

Histopathological changes in her kidneys and liver are likely to be due to hypoxemia during prolonged resuscitation after the second cardiac arrest. Liver dysfunctions occur in 25% of patients with rhabdomyolysis by various mechanisms including the released proteases causing liver inflammation [ 29 ]. This explains her high liver enzyme levels. Drugs like levetiracetam also might have contributed to kidney injury [ 30 ]. Her proteinuria is likely to be due to myoglobinuria.

A CSF analysis depicting chemical meningitis was reported in a past patient who had seizures following spinal anesthesia [ 31 ]. Nevertheless, our case and some similar cases did not show CSF evidence of chemical meningitis [ 1 , 2 , 3 , 5 ].

As explained above, her rhabdomyolysis, central hyperthermia, cardiomyopathy and postmortem changes observed in her lungs, kidneys and liver may be largely due to her super refractory status epilepticus with contributions from other factors. Her status epilepticus was due to ZUPIVAC H. That initiated the train of events leading directly to her death. Hence, the side effect of ZUPIVAC H most probably was her underlying cause of death [ 32 ]. However, we do not have adequate information to specifically identify the responsible component(s) of ZUPIVAC H.

Differential diagnoses we considered at different stages

We initially suspected a high spinal or local anesthetic systemic toxicity (LAST). In a patient with short stature and obesity, a high spinal can occur with a regular dose of heavy bupivacaine. The presence of a clear sensory level with preserved handgrip, the absence of any bloody tap, administering only 12.5 mg of bupivacaine, absence of other symptoms of LAST and no initial cardiac involvement indicated that those two possibilities are unlikely. At the end of the day1 and thereafter an adverse reaction to ZUPIVAC H, amniotic fluid embolism, normotensive eclampsia and previously undiagnosed brain pathology were the differential diagnoses. Amniotic fluid embolism is unlikely as at the onset there was no hypoxia with severe respiratory symptoms or cardiovascular collapse. Myoclonus is not the first sign of amniotic fluid embolism. Laboratory tests did not show significant coagulopathy. Later histopathology of the lungs also did not show evidence of amniotic fluid embolism [ 33 ]. Normotensive eclampsia is unlikely because there were no prior proteinuria, excess edema, or prodromal symptoms and onset of super-refractory status epilepticus after the delivery that did not respond to vigorous treatment [ 34 ]. Normal NCCT brain and later autopsy findings excluded previously undiagnosed brain pathology. Malignant hyperthermia (in addition to seizures) after giving suxamethonium is another possibility. However, reduction of ETCO 2 to 34-40mmHg range after admission to the ICU, fever spikes appearing on the following day (after the decrease of ETCO 2 ) and peaking on day 4 were against this possibility. Meningoencephalitis (infection) was also suspected as a reason for the high fever. The CSF analysis and autopsy findings excluded that possibility. At the end of both institutional death reviews, the final consensus was that this was an idiosyncratic reaction to ZUPIVAC H. After the extensive literature review by the first author, considering all available information, we now believe that this is most probably a case of direct local on-target type (mechanism-based) neurotoxicity on the CNS. As explained later, this can be categorized as an idiosyncratic reaction to ZUPIVAC H as well.

Discussion of central nervous system toxicity by bupivacaine and possible mechanisms of toxicity

The International Union of Basic and Clinical Pharmacology (IUPHAR) defines an adverse drug reaction (ADR) as an unwanted or harmful reaction experienced following the administration of a drug or combination of drugs under normal conditions of use and is suspected to be related to the drug [ 35 ]. Accordingly, this is an ADR. IUPHAR defines a side-effect as any effect caused by a drug other than the intended therapeutic effect [ 35 ]. The cesarean section was performed up to the delivery of the baby under spinal anesthesia induced by this drug alone (therapeutic effect was there). Additionally, there was this fatal side effect [ 35 ]. The United States Food and Drug Administration (FDA) use the terms adverse reactions and side effects as synonyms [ 36 ]. The IUPHAR defines drug toxicity as adverse effects of a drug that occur because the dose or plasma concentration has risen above the therapeutic range, either unintentionally or intentionally [ 35 ]. Accordingly, this is very unlikely to be drug toxicity due to the following reasons. She was given a therapeutic dose that has been in use worldwide for a long time [ 37 ]. Spinal anesthesia was working well during the onset of the seizures indicating that a certain percentage of drug molecules were bound to spinal cord receptors. Normally, the peak plasma concentration increase is approximately 0.4 mg/l (0.4 µg/ml) for every 100 mg of bupivacaine injected intrathecally and that peak takes about 50 min to occur [ 38 ]. Considering that there was no bloody tap, the maximum plasma concentration that possibly would have been achieved in 10–15 min after injection was very much lower than 2–3 µg/ml toxic threshold [ 38 , 39 ]. Some authors of past similar case reports considered their cases as LAST [ 3 , 4 ]. Nevertheless, LAST is a term to be used if plasma concentration exceeds the therapeutic range [ 4 , 39 , 40 , 41 , 42 ]. Anesthesiology trainees in Sri Lanka and elsewhere learn > 2 mg/kg as the toxic dose of bupivacaine unless it accidentally gets injected intravascularly [ 40 , 42 ]. Our patient was administered a far lower dose. Hence, LAST may not be an appropriate categorization for cases like this. Local neurotoxicity by local anesthetics is mentioned by a few past authors [ 41 , 43 ]. We think our case and similar cases following spinal anesthesia are more likely to be due to a category of direct local on-target type (mechanism-based) neurotoxicity on the CNS [ 44 ]. This category of toxicity appears to be occurring at unexpectedly low plasma and CSF concentrations, happens very rarely, thus, patient factors may also be playing a role. A case of cardiac toxicity (without seizures) following only 1.1 mg/kg of bupivacaine, injected cutaneously, was reported in a l-carnitine deficient patient [ 45 ]. This is one example of patient factors increasing the risk of bupivacaine toxicity. An experiment demonstrated that administration of supplemental l-carnitine could reverse this risk in rats [ 46 ]. Interestingly, l-carnitine deficiency is associated with seizures, cardiomyopathy, rhabdomyolysis, etc. as well [ 47 , 48 ]. We could not screen her for l-carnitine deficiency.

Toxic reactions usually occurs when the plasma concentration of total (bound and unbound) bupivacaine rise ≥ 2–3 µg/ml (generally ≥ 4 µg/ml) and when the unbound concentration ≥ 0.1–0.2 µg/ml [ 41 , 50 ]. Nonetheless, there is a report of an experiment where a similar aged healthy woman was slowly intravenously infused with bupivacaine and developed GTCS at a plasma concentration of ≥ 1.1 µg/ml [ 49 ]. Cases like ours may have been liable to develop seizures at even lower thresholds due to unidentified factors peculiar to the patient.

Further investigations into future similar cases, for patient factors like l-carnitine and alpha-1-acid glycoprotein deficiency (bupivacaine mostly binds to this protein) etc. would be helpful to clarify the pathophysiology of such events.

Another possible patient factor was either abnormal function or concentration of cell membrane receptors or both. We give an example. In one study, GIRK:Kir3 potassium channels of cell membranes were inhibited within seconds of bupivacaine application [ 50 ]. Other voltage-gated potassium channels are also inhibited by bupivacaine [ 50 ]. Those channels inhibition increase membrane excitability, which can result in seizures [ 50 ]. In one experiment, mice were genetically modified resulting in a lack of similar GIRK2 receptors [ 51 ]. They had spontaneous seizures and were prone to pharmacologically induced seizures as well [ 51 ]. Had her brain GIRK:Kir3 receptors been sparse, inhibition of existing ones by bupivacaine would have contributed to her seizures [ 50 ]. We do not have facilities for further investigation in that line. The impurity appeared to be structurally related to bupivacaine. Thus, it is reasonable to speculate that the impurity might also have inhibited those receptors, perhaps even stronger than bupivacaine. Further studies are necessary to clarify this matter.

Bupivacaine (regular) used for spinal anesthesia comes as a racemic mixture. Had bupivacaine administered to this patient contained more R-(+)-enantiomer, which is more potent that could have been more toxic at a lower dose [ 52 , 53 ]. We could not test ZUPIVAC H for enantiomers.

95% of bupivacaine in plasma is protein bound [ 40 ]. Bupivacaine binds to alpha-1-acid glycoprotein and to a lesser extent to albumin in plasma and in the CSF and unbound bupivacaine is responsible toxic effects [ 40 , 41 ]. If this patient’s CSF had very low levels of above the proteins due to genetic factors, the unbound bupivacaine concentration would have been higher. Serum alpha-1-acid glycoprotein levels decrease during pregnancy and serum levels are correlated with CSF levels [ 52 , 53 ]. This is another patient factor that would have facilitated neurotoxicity. Acidosis decreases protein binding of bupivacaine [ 50 ]. Initial acidosis would have raised unbound bupivacaine in her CSF. We could not test her plasma and CSF for those two proteins. Her preserved handgrip power and finding a sensory level at Th 7 indicate a considerable fraction of the drug injected remained attached to the spinal cord at the initiation of myoclonus/seizures (only a fraction has ascended to brain level). We could not find literature on the safe ceiling of CSF bupivacaine concentration. Future studies on safe CSF ceilings for local anesthetics would be worthy. Our patient never regained consciousness. No significant histopathological changes were seen in her brain. Several such past cases had changes in their EEG and/or MRI and took several days for neurological recovery [ 1 , 2 , 3 , 4 , 5 ]. Those indicate that some damage to brain neurons which are difficult detect in routine histopathology and take long time to recover, has happened in our patient and probably in other similar cases too.

Our patient had an extremely rarely occurring (novel) reaction likely to be due to bupivacaine that is very difficult to explain by the dose and known pharmacology of the drug. Considering the IUPHAR description of idiosyncrasy (type B ADRs) this is an idiosyncratic reaction as well [ 35 ]. Idiosyncratic liver damage due to bupivacaine has been reported [ 54 ]. Therefore, our and similar cases described in references 1–7 and 9 may be categorized as idiosyncrasies to bupivacaine. Nonetheless, Idiosyncratic reactions usually do not occur in a few minutes [ 55 ]. Immune reaction is a known reason behind idiosyncrasy.

This patient underwent uneventful spinal anesthesia for her first LSCS with bupivacaine five years ago. One plausible explanation is that the impurity may have played a role in precipitating seizures. Another possibility is that the patient factor(s) that made her susceptible to status epilepticus would have become clinically relevant in the recent past, even though those may be hereditary factors. For example, l-carnitine deficiency onset at age 39 has been reported [ 56 ].

We believe our analysis of possible patient factors would be helpful to investigators of future such cases to determine the pathophysiology of such seizures /status epilepticus. That will be helpful to improve the management and outcome of such cases.

2.5 ml of 0.5% bupiavacaine without dextrose is also used for spinal anesthesia without problems. As explained above, in this patient anesthesia worked as expected without a high spinal block. According to test results, the density of the batch No.DP2203 samples was 1.026 g/ml (at 20 0 C). Which is much higher than the density of CSF of pregnant women at term (about 1.00030 g/ml) [ 57 ]. Therefore, despite of standard dextrose concentration was not there (as pronounced by NMQAL), only a small fraction of administered bupivacaine would have ascended to her brain level and caused seizures. In one study, CSF bupivacaine concentrations for the same spinal block level differed between patients by sixfold after standardized administration of plain bupivacaine 20 mg [ 58 ]. That underscores the importance of patient factors in shaping CSF bupivacaine concentrations.

Our patient’s CSF bupivacaine concentration (especially unbound bupivacaine concentration) immediately after injection would have been on the higher side due to patient factors. In combination of other patient factors and probably with the impurity it would have caused direct neurotoxicity (seizures). Seizures resulted in other complications and ultimately her death.

Another possible reason for status epilepticus in our patient is the presence of epileptogenic impurities in the bupivacaine ampoule. We would like to give two examples. Pipecolic acid is used in bupivacaine synthesis [ 59 ]. The increase of pipecolic acid and correlated metabolites levels in the brain results in pyridoxine-dependent epilepsy [ 60 , 61 ]. Interestingly, pyridoxine-dependent epilepsy can result in super refractory status epilepticus [ 61 ]. Considering the possibility that some pipecolic acid remained in ZUPIVAC H used for our patient contributing to her seizures, we requested from TGA-Australia to look for that. They did not have facilities to perform relevant tests.

During the process of manufacturing heavy bupivacaine, due to heat, variety of glucose degradation products like 5-Hydroxymethylfurfural could be formed from dextrose [ 62 ]. Some of them have neurotoxic and cytotoxic properties after parenteral administration [ 62 , 63 ]. TGA-Australia, on our request tested for 5-Hydroxymethylfurfural and related substances and their levels in the sample were within the permitted levels as per British Pharmacopeia (BP). TGA-Australia looked for the toxic impurity 2,6-dimethylaniline specified in the BP and Indian Pharmacopoeia, but did not detect this compound in the sample.

Lessons to be learned and the way forward

Ours is a rare and extreme case, and only six similar cases are in the literature. Nonetheless, there are more published milder cases of likely central nervous neurotoxicity occurring after spinal anesthesia [ 15 ]. Published cases are usually the tip of the iceberg. As mentioned in the background, this single case had a big negative impact on the Sri Lankan healthcare system, Sri Lankan society and the reputation of pharmaceutical industry [ 9 ]. All considered, it is crucial to do further studies on the broad subject. Also, it is essential to take actions to prevent recurrences considering existing evidence. We do not know whether the impurity detected in ZUPIVAC H has epileptogenic properties when injected into the CSF. Extraction of the impurity, identification and test injection to laboratory animals CSF may be helpful to determine whether that was responsible for seizures in our patient. Early spinal anesthetic agents have not undergone considerable controlled testing for neurotoxicity according to a review article [ 64 ]. Such studies done according to present standards on spinal anesthetic agents used currently, especially bupivacaine, may throw light on the pathophysiology of similar cases and potential treatments. Previously, we discussed possible mechanisms that can result in cases like ours. We hope that will give a good idea to investigators of future cases where to focus their attention. If an international body takes the initiative to introduce clear consensus definitions to common terms like drug toxicity, LAST and direct neurotoxicity by local anesthetics, that would benefit the medical community. Initiation of a discussion among anesthesiology community to categorize CNS toxicity after subarachnoid injection of local anesthetics as a special category of side effects is worthy. The risk of similar incidents is not mentioned in some manufacturers’ literature. There is no manufacturer’s literature leaflet in the five ampoule packs of ZUPIVAC H. We think the availability of manufacturer’s literature and mentioning the remote risk of such side effects in the manufacturer’s literature of heavy bupivacaine are essential. Although we are from a different country, TGA-Australia kindly analyzed our ZUPIVAC H samples generating information that would be valuable to healthcare community worldwide. It is a good example of the usefulness of international cooperation in investigating such cases. One recent study shows that impurities (contamination) are the commonest cause of defective medicines in Sri Lanka [ 65 ]. Continuous maintenance of a strict quality control process from raw materials to the end product level and adherence to good manufacturing practice protocols by manufacturers can prevent impurities from contaminating bupivacaine. Enhancement of capabilities and effectiveness of the National Medicines Regulatory Authority (NMRA) of Sri Lanka and fully implementation of quality assurance mechanisms always (even during emergency drug procurements and accepting donations of medicines by the Health Ministry) would be useful to ensure the quality, safety and efficacy of bupivacaine at hospitals [ 65 ]. Strengthening post marketing surveillance work on anesthetic drugs by NMRA-Sri Lanka is also worthy. Looking for impurities in heavy bupivacaine in the case of an incident like our case is not in the USP monographs for quality tests. We believe if relevant authorities can consider the inclusion of testing for impurities for quality tests it would be worthy. Administration of 20% fat emulsion to act as an intravenous sink to remove bupivacaine from neurons was one therapy we could have used and that had been used to manage similar cases [ 4 , 40 , 42 ]. 20% fat emulsion was unavailable locally. We suggest to keep at least one bottle of 20% fat emulsion in every operating theater to be used in cases like this. Some readers may think that we could have used propofol to induce and maintain general anesthesia because that contains lipid as well. However, reported cases of seizures due to propofol came to the minds of the team members desperately managing status epilepticus at that time and we used time tested thiopentone (thiopental) [ 66 ]. Propofol was used to manage several similar patients who survived [ 1 , 2 , 3 , 4 , 5 , 14 ]. Thus, we retrospectively think that its benefits might outweigh the risk of aggravated seizures. However, one case treated with thiopentone also survived [ 7 ]. Further studies may clarify this issue. Research to develop an antidote for bupivacaine neurotoxicity with better efficacy would be meritorious. During our literature survey, we noticed that several similar cases (seizures) and several deaths had occurred related to spinal anesthesia by accidental administration of tranexamic acid instead of bupivacaine [ 67 ]. We have excluded that possibility in our case. However, we would like to draw the attention of the anesthesiology community to that issue and reiterate the importance of always adhering to standard safety procedures when administering spinal anesthesia to avoid such medication errors.

Neurotoxicity by bupivacaine (ZUPIVAC H) at spinal cord level would have started myoclonus in this patient. After the drug traveled to the brain, neurotoxicity would have resulted in the super-refractory status epilepticus. Super-refractory status epilepticus would have led to the other complications ending in her death. Patient factors are likely to have made her susceptible to neurotoxicity. There are several such potential factors. The impurity in the drug would also have contributed to her status epilepticus. There are several possible mechanisms that would have led to status epilepticus and her death, which we discussed. Awareness of those mechanisms would be useful to investigators in such future cases. Implementation of our aforementioned suggestions would be helpful to minimize similar future incidents.

Data availability

All relevant data is incorporated in to the manuscript.

Abbreviations

American Society of Anesthesiologists

Central nervous system

Elective lower segment Cesarean section

Intravenous

Generalized tonic clonic seizures

Electrocardiogram

Chest X ray

Intensivecare unit

Nasogastric (tube)

Non-contrast CT scan

Cerebrospinal fluid

Electroencephalogram

International normalized ratio

Magnetic resonance imaging

Cardiopulmonary resuscitation

United States Pharmacopeia

National Medicines Quality Assurance Laboratory

Therapeutic Goods Administration

C-reactive protein

International Union of Basic and Clinical Pharmacology

Adverse drug reaction

Food and Drug Administration

Local anesthetic systemic toxicity

Indian pharmacopoeia

British pharmacopeia

Akıl E, Varol S, Güzel A, Göçmez C. Status epilepticus induced by intrathecal bupivacaine use: A case report. J Clin Exp Invest www.jceionline. org Vol. 2014;5(1). https://pdfs.semanticscholar.org/ba7f/a509a440b236ec0488475229b0a0d1167df4.pdf

Kaur J, Gill SK, Kumari A, Walia C, Kaur H. Generalized tonic-clonic seizures following spinal anesthesia using bupivacaine for cesarean section: a case report. AMEI’s Curr Trends Diagn Treat. 2020;4(1):29–30. https://doi.org/10.5005/jp-journals-10055-0081 . https://web.archive.org/web/20220119111632id_/https://www.ctdt.co.in/doi/pdf/

Article   Google Scholar  

Vanmarcke A, Lormans P, Vandewaeter C. Status Epilepticus following Intrathecal Administration of Bupivacaine: a Case Report. J Investig Med High Impact Case Rep. 2022;10:23247096221090841. https://doi.org/10.1177/23247096221090841 . https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9024154/

Article   PubMed   PubMed Central   Google Scholar  

Lavado P, Carvalho E, Almeida M, Taveira I, Pádua F. A myriad of symptoms after spinal anesthesia: a Case Report of local anesthetic systemic toxicity. Cureus. 2022;14(10):e29902. https://doi.org/10.7759/cureus.29902 . Published 2022 Oct 4.

Thakur AK, Rathour K, Lall R, Satija S, Gupta S. Super refractory status epilepticus in a parturient with preeclampsia undergoing cesarean delivery under spinal anesthesia. 2022 Jun 4:134–6. https://doi.org/10.32677/ijcr.v8i5.3401

Patel AK, Verma N. Status Epilepticus Following Intrathecal Administration Of 0.5% Heavybupivacaine: A Case Report. NeuroQuantology.2022;20:19. Page 2012–2016. https://doi.org/10.48047/nq.2022.20.19.NQ99173

Lee HW, Chang SH. Postoperative idiopathic generalized Convulsion Conversed to Generalized Status Epilepticus following spinal anesthesia. Korean J Anesthesiology. 1994;27(6):649–54. https://doi.org/10.4097/kjae.1994.27.6.649

Dubey D, Kalita J, Misra UK. Status epilepticus: refractory and super-refractory. Neurol India. 2017;65(Supplement):S12–7. https://doi.org/10.4103/neuroindia.NI_958_16

Article   PubMed   Google Scholar  

Sirinivasan M. Indian medicines under lens in Sri Lanka over a series of adverse events. Hindu World June 19, 2023. https://www.thehindu.com/news/international/indian-drugs-under-lens-in-sri-lanka-over-adverse-events/article66982831.ece

Dundee JW, THIOPENTONE AS A FACTOR IN, THE PRODUCTION OF LIVER DYSFUNCTION. Br J Anaesth. 1955;27:14–23. https://pubmed.ncbi.nlm.nih.gov/13230358/

Article   CAS   PubMed   Google Scholar  

D’Andria Ursoleo J, Licheri M, Barucco G, Breggion S, De Simone F, Monaco F. Management of microvascular bleeding after On-Pump cardiac surgery in a patient with Perioperative diagnosis of impairment of platelet responses to Adenosine Diphosphate: a Case Report and a literature review. J Clin Med. 2023;12:6372.

Malter MP, Neuneier J. Super-refractory status epilepticus in adults. Neurol Res Pract. 2022;4:35.

Dumitru AP. Garcia ER,Burkhart SE,Potter JK.Convulsive Seizure following spinal anesthesia for cesarean section: possible etiologic factors. Anesth Analg. 1962;41:4. Page 423.

Kim HJ, Kwon MY, Kang HJ, Koo MS, Park JC, Lee M. Generalized tonic-clonic seizure following spinal anesthesia for cesarean section with bupivacaine: a case report. Anesth Pain Med. 2011;6(4):393–6. https://anesth-pain-med.org/journal/view.php?number=549

Google Scholar  

Song W, Zhang H, Li X, Yu C, Zhou Y, Li Y et al. Delayed lethal central nervous system toxicity induced by a low-dose intrathecal administration of bupivacaine: case report. Front Anesthesiol. 2023;2.

Ray B, Baidya D, Gregory D, Sunder R. Intraoperative neurological event during cesarean section under spinal anesthesia with fentanyl and bupivacaine: case report and review of literature. J Anaesthesiol Clin Pharmacol. 2012;28:374.

Article   CAS   PubMed   PubMed Central   Google Scholar  

Sakka L, Coll G, Chazal J. Anatomy and physiology of cerebrospinal fluid. Eur Ann Otorhinolaryngol Head Neck Dis. 2011;128:309–16.

Sung CY, Lee TH, Chu NS. Central hyperthermia in acute stroke. Eur Neurol. 2009;62(2):86–92. https://doi.org/10.1159/000222778

Hanin A, Lambrecq V, Denis JA, et al. Cerebrospinal fluid and blood biomarkers of status epilepticus. Epilepsia. 2020;61(1):6–18. https://doi.org/10.1111/epi.16405

Hawkes MA, Hocker SE. Systemic complications following Status Epilepticus. Curr Neurol Neurosci Rep. 2018;18(2):7. https://doi.org/10.1007/s11910-018-0815-9 . Published 2018 Feb 7.

Sutter R, Dittrich T, Semmlack S, Rüegg S, Marsch S, Kaplan PW. Acute systemic complications of Convulsive Status Epilepticus-A systematic review. Crit Care Med. 2018;46(1):138–45. https://doi.org/10.1097/CCM.0000000000002843

Kang DH, Kim J, Rhee JE, et al. The risk factors and prognostic implication of acute pulmonary edema in resuscitated cardiac arrest patients. Clin Exp Emerg Med. 2015;2(2):110–6. https://doi.org/10.15441/ceem.14.016 . Published 2015 Jun 30.

Siniscalchi A, Mintzer S, De Sarro G, Gallelli L. Myotoxicity Induced by antiepileptic drugs: could be a rare but serious adverse event? Psychopharmacol Bull. 2021;51(4):105–16.

PubMed   PubMed Central   Google Scholar  

Ehelepola NDB, Sathkumara SMBY, Bandara HMPAGS, Kalupahana KLR. Atorvastatin-Diltiazem Combination Induced Rhabdomyolysis leading to diagnosis of Hypothyroidism. Case Rep Med. 2017;2017:8383251. https://doi.org/10.1155/2017/8383251

Centers for Disease Control and Prevention (USA). Epilepsy. About epilepsy. Sudden unexpected death in Epilepsy (SUDEP). CDC September 30, 2020. https://www.cdc.gov/epilepsy/about/sudep/index.htm

Nandal S, Castles A, Asrar Ul Haq M, van Gaal W. Takotsubo cardiomyopathy triggered by status epilepticus: case report and literature review. BMJ Case Rep. 2019;12(1):e225924. Published 2019 Jan 29. https://doi.org/10.1136/bcr-2018-225924

Ryu HY, Kim JY, Lim HK, et al. Bupivacaine induced cardiac toxicity mimicking an acute non-ST segment elevation myocardial infarction. Yonsei Med J. 2007;48(2):331–6. https://doi.org/10.3349/ymj.2007.48.2.331

Park JY, Kang HR, Kim JH, Kim HW, Kim SM, Chang YJ, Choe KH, Lee KM, An JY. Fatal Peripartum Cardiomyopathy after Bupivacaine Local Injection in Elective Cesarean section: a Case Report. J Korean Soc Emerg Med. 2016;27(2):214–8.

Zutt R, van der Kooi AJ, Linthorst GE, Wanders RJ, de Visser M. Rhabdomyolysis: review of the literature. Neuromuscul Disord. 2014;24(8):651–9. https://doi.org/10.1016/j.nmd.2014.05.005

Erdinc B, Ghanta S, Andreev A, Elkholy KO, Sahni S. Acute kidney Injury caused by Levetiracetam in a patient with Status Epilepticus. Cureus. 2020;12(6):e8814. https://doi.org/10.7759/cureus.8814 . Published 2020 Jun 24.

Predrijevac A, Šustić A, Antončić I, Dunatov S, Župan Ž, Kuharić J, Dangubić B, Sotošek Tokmadžić V. Chemical Meningitis following spinal analgesia with levobupivacaine in Labor and Delivery: a Case Report. Anesth Pain Res. 2017;1(1):1–3. https://doi.org/10.33425/2639-846X.1004

World Health Organization. International Classification of Diseases (ICD). Cause of death. Reporting cause of death. 2022. WHO. https://www.who.int/standards/classifications/classification-of-diseases/cause-of-death

Kaur K, Bhardwaj M, Kumar P, Singhal S, Singh T, Hooda S. Amniotic fluid embolism. J Anaesthesiol Clin Pharmacol. 2016;32:153.

Magley M, Hinson MR, Eclampsia. 2024. https://www.ncbi.nlm.nih.gov/books/NBK554392/

International Union of Basic and Clinical Pharmacology. The Pharmacology Education Project. Adverse drug reactions. IUPHAR. https://www.pharmacologyeducation.org/clinical-pharmacology/adverse-drug-reactions

United States Food and Drug Administration. Resources for You | Drugs. Finding and Learning about Side Effects (adverse reactions). 08/08/2022. https://www.fda.gov/drugs/information-consumers-and-patients-drugs/finding-and-learning-about-side-effects-adverse-reactions#:~:text=A side effect is considered,during pregnancy caused birth defect.&text=increase or decrease the dose,a drug that you take

Białowolska K, Horosz B, Sękowska A, Malec-Milewska M. Fixed dose versus height-adjusted conventional dose of Intrathecal hyperbaric bupivacaine for caesarean delivery: a prospective, double-blinded Randomised Trial. J Clin Med. 2020;9(11):3600. https://doi.org/10.3390/jcm9113600 . Published 2020 Nov 8.

Electronic medicines compendium (of U.K.). Bupivacaine Heavy 5 mg/ml Solution for Injection. Pharmacological properties. 5.2 Pharmacokinetic properties. EMC. 2020 https://www.medicines.org.uk/emc/product/11160/smpc#gref

Dontukurthy S, Tobias JD. Update on local anesthetic toxicity, Prevention and Treatment during Regional Anesthesia in infants and children. J Pediatr Pharmacol Ther. 2021;26(5):445–54. https://doi.org/10.5863/1551-6776-26.5.445

Taylor A, McLeod G. Basic pharmacology of local anaesthetics [published correction appears in BJA Educ. 2020;20(4):140]. BJA Educ. 2020;20(2):34–41. https://doi.org/10.1016/j.bjae.2019.10.002

El-Boghdadly K, Pawa A, Chin KJ. Local anesthetic systemic toxicity: current perspectives. Local Reg Anesth. 2018;11:35–44. https://doi.org/10.2147/LRA.S154512 . Published 2018 Aug 8.

Gitman M, Fettiplace M, Weinberg G. Local Anesthetic Systemic Toxicity. New York School of Regional Anesthesia. https://www.nysora.com/topics/complications/local-anesthetic-systemic-toxicity/

Dippenaar JM. Local anaesthetic toxicity. South Afr J Anaesth Analgesia. 2007;13(3):23–8. https://www.ajol.info/index.php/sajaa/article/view/62175

Guengerich FP. Mechanisms of drug toxicity and relevance to pharmaceutical development. Drug Metab Pharmacokinet. 2011;26(1):3–14. https://doi.org/10.2133/dmpk.dmpk-10-rv-062

Weinberg GL, Laurito CE, Geldner P, Pygon BH, Burton BK. Malignant ventricular dysrhythmias in a patient with isovaleric acidemia receiving general and local anesthesia for suction lipectomy. J Clin Anesth. 1997;9(8):668–70. https://doi.org/10.1016/s0952-8180(97)00187-6

Wong GK, Crawford MW. Carnitine deficiency increases susceptibility to bupivacaine-induced cardiotoxicity in rats. Anesthesiology. 2011;114(6):1417–24. https://doi.org/10.1097/ALN.0b013e31821a8d46

Kumar P, Chauhan L, Vohra R, Garg A. Primary carnitine deficiency presenting as intractable seizures. Neurol India. 2015;63(2):272–4. https://doi.org/10.4103/0028-3886.156308

Dahash BA, Sankararaman S. Carnitine deficiency. InStatPearls [Internet] 2022 May 1. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK559041/

Hasselstrom L, Mogensen T. Toxic reaction of bupivacaine at low plasma concentration. Anesthesiology. 1984;61:99–100.

Zhou W, Arrabit C, Choe S, Slesinger PA. Mechanism underlying bupivacaine inhibition of G protein-gated inwardly rectifying K + channels. Proc Natl Acad Sci U S A. 2001;98(11):6482–7. https://doi.org/10.1073/pnas.111447798

Signorini S, Liao YJ, Duncan SA, Jan LY, Stoffel M. Normal cerebellar development but susceptibility to seizures in mice lacking G protein-coupled, inwardly rectifying K + channel GIRK2. Proc Natl Acad Sci U S A. 1997;94(3):923–7. https://doi.org/10.1073/pnas.94.3.923

Zapata-Sudo G, Trachez MM, Sudo RT, Nelson TE. Is comparative cardiotoxicity of S(-) and R(+) bupivacaine related to enantiomer-selective inhibition of L-type ca(2+) channels? Anesth Analg. 2001;92(2):496–501. https://doi.org/10.1097/00000539-200102000-00040

Souza MCO, Marques MP, Duarte G, Lanchote VL. Analysis of bupivacaine enantiomers in plasma as total and unbound concentrations using LC-MS/MS: application in a pharmacokinetic study of a parturient with placental transfer. J Pharm Biomed Anal. 2019;164:268–75.

Ahmed ST, Patel S, Kamal S, et al. Drug-Induced Liver Injury caused by Bupivacaine. Am J Ther. 2020;28(6):e785–8. https://doi.org/10.1097/MJT.0000000000001132 . Published 2020 Jan 23.

Uetrecht J, Naisbitt DJ. Idiosyncratic adverse drug reactions: current concepts. Pharmacol Rev. 2013;65(2):779–808. https://doi.org/10.1124/pr.113.007450 . Published 2013 Mar 8.

Levitan MD, Murphy JT, Sherwood WG, Deck J, Sawa GM. Adult onset systemic carnitine deficiency: favorable response to L-carnitine supplementation [published correction appears in Can J Neurol Sci 1987;14(2):189]. Can J Neurol Sci. 1987;14(1):50–4. https://doi.org/10.1017/s0317167100026172

Richardson MG, Wissler RN. Density of lumbar cerebrospinal fluid in pregnant and nonpregnant humans. Anesthesiology. 1996;85(2):326–30. https://doi.org/10.1097/00000542-199608000-00014

Ruppen W, Steiner LA, Drewe J, Hauenstein L, Brugger S, Seeberger MD. Bupivacaine concentrations in the lumbar cerebrospinal fluid of patients during spinal anaesthesia. Br J Anaesth. 2009;102(6):832–8. https://doi.org/10.1093/bja/aep049

Kumar S, Ramachandran U. Studies directed towards asymmetric synthesis of levobupivacaine. Tetrahedron Lett. 2005;46(1):19–21.

Article   CAS   Google Scholar  

Coughlin CR 2nd, Tseng LA, Abdenur JE, Ashmore C, Boemer F, Bok LA, Boyer M, Buhas D, Clayton PT, Das A, Dekker H, Evangeliou A, Feillet F, Footitt EJ, Gospe SM Jr, Hartmann H, Kara M, Kristensen E, Lee J, Lilje R, Longo N, Lunsing RJ, Mills P, Papadopoulou MT, Pearl PL, Piazzon F, Plecko B, Saini AG, Santra S, Sjarif DR, Stockler-Ipsiroglu S, Striano P, Van Hove JLK, Verhoeven-Duif NM, Wijburg FA, Zuberi SM, van Karnebeek CDM. Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency. J Inherit Metab Dis. 2021;44(1):178–92. https://doi.org/10.1002/jimd.12332 . Epub 2020 Dec 1.

Kaminiów K, Pająk M, Pająk R, Paprocka J. Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency resulting in neonatal-onset refractory seizures. Brain Sci. 2021;12(1):65. https://doi.org/10.3390/brainsci12010065

Leitzen S, Vogel M, Engels A, Zapf T, Brandl M. Identification and quantification of glucose degradation products in heat-sterilized glucose solutions for parenteral use by thin-layer chromatography. PLoS ONE. 2021;16(7):e0253811. https://doi.org/10.1371/journal.pone.0253811 . Published 2021 Jul 2.

Wang C, Liu Z, Hu T, Li Y, Liu R, Zhang J, He H. Potential neurotoxicity of 5-hydroxymethylfurfural and its oligomers: widespread substances in carbohydrate-containing foods. Food Funct. 2020;11(5):4216–23. https://doi.org/10.1039/c9fo02526j

Hodgson PS, Neal JM, Pollock JE, Liu SS. The neurotoxicity of drugs given intrathecally (spinal). Anesth Analg. 1999;88:797–809.

CAS   PubMed   Google Scholar  

Tharmalinga Sharma JJ, Ketharam M, Herath KB, Shobia SS. Quality of medicines in Sri Lanka: a retrospective review of safety alerts. BMC Health Serv Res. 2023;23:980.

Finley GA, MacManus B, Sampson SE, Fernandez CV, Retallick R. Delayed seizures following sedation with propofol. Can J Anaesth. 1993;40(9):863–5. https://doi.org/10.1007/BF03009258 . –prpofol seizures.

Patel S. Tranexamic acid-associated intrathecal toxicity during spinal anaesthesia. Eur J Anaesthesiol. 2023;40:334–42.

Download references

Acknowledgements

Authors sincerely thank all doctors and all other healthcare workers who contributed to manage this patient, conducted postmortem and histopathology work, death review and analysis of drug samples. We thank all who helped us to publish this article. Special thanks to Amanda Kalachoff and her team of the Therapeutic Goods Administration of Australia who analyzed drug samples and the director of our hospital who co-operated in this endeavor.

No funding received.

Author information

Authors and affiliations.

Teaching (General) Hospital – Peradeniya, Peradeniya, Sri Lanka

N. D.B. Ehelepola, R. M.D.C. Ranathunga, A. B. Abeysundara, H. M.R.P. Jayawardana & P. S.K. Nanayakkara

Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka

A. B. Abeysundara & P. S.K. Nanayakkara

You can also search for this author in PubMed   Google Scholar

Contributions

NDBE-Conducted institutional death review meeting of this maternal death, literature survey, conceptualization of this study, wrote the original draft and final manuscript. RMDCR- Initial management of patient, review the original draft. HMRPJ–administered spinal anesthesia, initial management of complications, review the original draft. ABA- Late management of the patient, systematic literature survey verification, review the original draft. PSKN- Late management of the patient, review the original draft. All authors read and approved the final manuscript.

Corresponding author

Correspondence to N. D.B. Ehelepola .

Ethics declarations

Ethics approval and consent to participate.

Not applicable.

Consent for publication

The authors declare that the patient died. Therefore written informed consent for publication was obtained from the patients’ husband.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Supplementary material 2, rights and permissions.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/ ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article.

Ehelepola, N.D., Ranathunga, R.M., Abeysundara, A.B. et al. Super-refractory status epilepticus, rhabdomyolysis, central hyperthermia and cardiomyopathy attributable to spinal anesthesia: a case report and review of literature. BMC Anesthesiol 24 , 132 (2024). https://doi.org/10.1186/s12871-024-02485-x

Download citation

Received : 21 December 2023

Accepted : 07 March 2024

Published : 06 April 2024

DOI : https://doi.org/10.1186/s12871-024-02485-x

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Bupivacaine
• Spinal anesthesia
• Status epilepticus
• Rhabdomyolysis
• Hyperthermia
• Idiosyncrasy
• Cardiomyopathy
• Side effect
• Case report

BMC Anesthesiology

ISSN: 1471-2253

• Submission enquiries: [email protected]
• General enquiries: [email protected]

• International edition
• Australia edition
• Europe edition

Gender medicine ‘built on shaky foundations’, Cass review finds

Analysis finds most research underpinning clinical guidelines, hormone treatments and puberty blockers to be low quality

Review of gender services has major implications for mental health services

The head of the world’s largest review into children’s care has said that gender medicine is “built on shaky foundations”.

Dr Hilary Cass, the paediatrician commissioned to conduct a review of the services provided by the NHS to children and young people questioning their gender identity, said that while doctors tended to be cautious in implementing new findings in emerging areas of medicine, “quite the reverse happened in the field of gender care for children”.

Cass commissioned the University of York to conduct a series of analyses as part of her review.

Two papers examined the quality and development of current guidelines and recommendations for managing gender dysphoria in children and young people. Most of the 23 clinical guidelines reviewed were not independent or evidence based, the researchers found.

A third paper on puberty blockers found that of 50 studies, only one was of high quality.

Similarly, of 53 studies included in a fourth paper on the use of hormone treatment, only one was of sufficiently high quality, with little or only inconsistent evidence on key outcomes.

Here are the main findings of the reviews:

Clinical guidelines

Increasing numbers of children and young people experiencing gender dysphoria are being referred to specialist gender services. There are various guidelines outlining approaches to the clinical care of these children and adolescents.

In the first two papers, the York researchers examined the quality and development of published guidelines or clinical guidance containing recommendations for managing gender dysphoria in children and young people up to the age of 18.

They studied a total of 23 guidelines published in different countries between 1998 and 2022. All but two were published after 2010.

Most of them lacked “an independent and evidence-based approach and information about how recommendations were developed”, the researchers said.

Few guidelines were informed by a systematic review of empirical evidence and they lack transparency about how their recommendations were developed. Only two reported consulting directly with children and young people during their development, the York academics found.

“Healthcare services and professionals should take into account the poor quality and interrelated nature of published guidance to support the management of children and adolescents experiencing gender dysphoria/incongruence,” the researchers wrote.

Writing in the British Medical Journal (BMJ) , Cass said that while medicine was usually based on the pillars of integrating the best available research evidence with clinical expertise, and patient values and preferences, she “found that in gender medicine those pillars are built on shaky foundations”.

She said the World Professional Association of Transgender Healthcare (WPATH) had been “highly influential in directing international practice, although its guidelines were found by the University of York’s appraisal to lack developmental rigour and transparency”.

In the foreword to her report, Cass said while doctors tended to be cautious in implementing new findings “quite the reverse happened in the field of gender care for children”.

In one example, she said a single Dutch medical study, “suggesting puberty blockers may improve psychological wellbeing for a narrowly defined group of children with gender incongruence”, had formed the basis for their use to “spread at pace to other countries”. Subsequently, there was a “greater readiness to start masculinising/feminising hormones in mid-teens”.

She added: “Some practitioners abandoned normal clinical approaches to holistic assessment, which has meant that this group of young people have been exceptionalised compared to other young people with similarly complex presentations. They deserve very much better.”

Both papers repeatedly pointed to a key problem in this area of medicine: a dearth of good data.

She said: “Filling this knowledge gap would be of great help to the young people wanting to make informed choices about their treatment.”

Cass said the NHS should put in place a “full programme of research” looking at the characteristics, interventions and outcomes of every young person presenting to gender services, with consent routinely sought for enrolment in a research study that followed them into adulthood.

Gender medicine was “an area of remarkably weak evidence”, her review found, with study results also “exaggerated or misrepresented by people on all sides of the debate to support their viewpoint”.

Alongside a puberty blocker trial, which could be in place by December, there should be research into psychosocial interventions and the use of the masculinising and feminising hormones testosterone and oestrogen, the review found.

Hormone treatment

Many trans people who seek medical intervention in their transition opt to take hormones to masculinise or feminise their body, an approach that has been used in transgender adults for decades.

“It is a well-established practice that has transformed the lives of many transgender people,” the Cass review notes, adding that while these drugs are not without long-term problems and side-effects, for many they are dramatically outweighed by the benefits.

For birth-registered females, the approach means taking testosterone, which brings about changes including the growth of facial hair and a deepening of the voice, while for birth-registered males, it involves taking hormones including oestrogen to promote changes including the growth of breasts and an increase in body fat. Some of these changes may be irreversible.

However, in recent years a growing proportion of adolescents have begun taking these cross-sex, or gender-affirming, hormones, with the vast majority who are prescribed puberty blockers subsequently moving on to such medication.

This growing take-up among young people has led to questions over the impact of these hormones in areas ranging from mental health to sexual functioning and fertility.

Now researchers at the University of York have carried out a review of the evidence, comprising an analysis of 53 previously published studies, in an attempt to set out what is known – and what is not – about the risks, benefits and possible side-effects of such hormones on young people.

All but one study, which looked at side-effects, were rated of moderate or low quality, with the researchers finding limited evidence for the impact of such hormones on trans adolescents with respect to outcomes, including gender dysphoria and body satisfaction.

The researchers noted inconsistent findings around the impact of such hormones on growth, height, bone health and cardiometabolic effects, such as BMI and cholesterol markers. In addition, they found no study assessed fertility in birth-registered females, and only one looked at fertility in birth-registered males.

“These findings add to other systematic reviews in concluding there is insufficient and/or inconsistent evidence about the risks and benefits of hormone interventions in this population,” the authors write.

However, the review did find some evidence that masculinising or feminising hormones might help with psychological health in young trans people. An analysis of five studies in the area suggested hormone treatment may improve depression, anxiety and other aspects of mental health in adolescents after 12 months of treatment, with three of four studies reporting an improvement around suicidality and/or self-harm (one reported no change).

But unpicking the precise role of such hormones is difficult. “Most studies included adolescents who received puberty suppression, making it difficult to determine the effects of hormones alone,” the authors write, adding that robust research on psychological health with long-term follow-up was needed.

The Cass review has recommended NHS England should review the current policy on masculinising or feminising hormones, advising that while there should be the option to provide such drugs from age 16, extreme caution was recommended, and there should be a clear clinical rationale for not waiting until an individual reached 18.

Puberty blockers

Treatments to suppress puberty in adolescents became available through routine clinical practice in the UK a decade ago.

While the drugs have long been used to treat precocious puberty – when children start puberty at an extremely young age – they have only been used off-label in children with gender dysphoria or incongruence since the late 1990s. The rationale for giving puberty blockers, which originated in the Netherlands, was to buy thinking time for young people and improve their ability to smooth their transition in later life.

Data from gender clinics reported in the Cass review showed the vast majority of people who started puberty suppression went on to have masculinising or feminising hormones, suggesting that puberty blockers did not buy people time to think.

To understand the broader effects of puberty blockers, researchers at the University of York identified 50 papers that reported on the effects of the drugs in adolescents with gender dysphoria or incongruence. According to their systematic review, only one of these studies was high quality, with a further 25 papers regarded as moderate quality. The remaining 24 were deemed too weak to be included in the analysis.

Many of the reports looked at how well puberty was suppressed and the treatment’s side-effects, but fewer looked at whether the drugs had their intended benefits.

Of two studies that investigated gender dysphoria and body satisfaction, neither found a change after receiving puberty blockers. The York team found “very limited” evidence that puberty blockers improved mental health.

Overall, the researchers said “no conclusions” could be drawn about the impact on gender dysphoria, mental and psychosocial health or cognitive development, though there was some evidence bone health and height may be compromised during treatment.

Based on the York work, the Cass review finds that puberty blockers offer no obvious benefit in helping transgender males to help their transition in later life, particularly if the drugs do not lead to an increase in height in adult life. For transgender females, the benefits of stopping irreversible changes such as a deeper voice and facial hair have to be weighed up against the need for penile growth should the person opt for vaginoplasty, the creation of a vagina and vulva.

In March, NHS England announced that children with gender dysphoria would no longer receive puberty blockers as routine practice. Instead, their use will be confined to a trial that the Cass review says should form part of a broader research programme into the effects of masculinising and feminising hormones.

• Transgender
• Young people

More on this story

Five thousand children with gender-related distress awaiting NHS care in England

Ban on children’s puberty blockers to be enforced in private sector in England

What Cass review says about surge in children seeking gender services

Adult transgender clinics in England face inquiry into patient care

‘Children are being used as a football’: Hilary Cass on her review of gender identity services

Thousands of children unsure of gender identity ‘let down by NHS’, report finds

What are the key findings of the NHS gender identity review?

Mother criticises ‘agenda from above’ after release of Cass report

Cass review set to confirm shift in NHS care for children with gender dysphoria

Most viewed.