Accessibility settings

This paper is in the following e-collection/theme issue:

Scoping Review Protocols (286) Nursing (143) Search Strategies and Retrieval for Systematic Reviews (20) Preoperative Measures for Prevention (43) Nursing in a Hospital Setting (142) Intensive Care Unit (ICU) (168)

Published on in Vol 15 (2026)

Preprints (earlier versions) of this paper are available at https://preprints.jmir.org/preprint/84080, first published .
Point-of-Care Ultrasound in the Assessment of Gastric Residual Volume: Protocol for a Scoping Review

Point-of-Care Ultrasound in the Assessment of Gastric Residual Volume: Protocol for a Scoping Review

Point-of-Care Ultrasound in the Assessment of Gastric Residual Volume: Protocol for a Scoping Review

Authors of this article:

Fernanda Raphael Escobar Gimenes1 Author Orcid Image ;   Renata Pinheiro Lopes1 Author Orcid Image ;   Mariana de Magalhaes Framartino1 Author Orcid Image ;   Rosana Aparecida Pereira1 Author Orcid Image ;   Priscilla Roberta Silva Rocha2 Author Orcid Image ;   Vinicius Batista Santos3 Author Orcid Image
Article Authors Cited by Tweetations Metrics

    1Department of General and Specialized Nursing, University of São Paulo at Ribeirão Preto College of Nursing, Avenida Bandeirantes, 3900, Ribeirão Preto, Brazil

    2Department of Nursing, University of Brasília, Faculty of Health Sciences and Technology, Brasilia, Brazil

    3Department of Clinical and Surgical Nursing, Federal University of São Paulo, Paulista School of Nursing, São Paulo, Brazil

    *these authors contributed equally

    Corresponding Author:

    Fernanda Raphael Escobar Gimenes, RN, PhD


    Background: Pulmonary aspiration of gastric contents is a serious clinical complication, particularly in patients receiving enteral nutrition or undergoing anesthesia. Gastric residual volume (GRV) is a commonly used surrogate marker that can identify delayed gastric emptying and enteral nutrition intolerance, both of which may increase the risk of aspiration. Traditional methods for measuring GRV are invasive and lack standardization. Point-of-care ultrasound (PoCUS) has emerged as a promising, noninvasive bedside alternative. Despite its growing clinical use, there is still no consolidated guidance on PoCUS procedures for GRV assessment in adult patients.

    Objective: This scoping review aims to map and synthesize the available evidence on procedural techniques, interpretation criteria, and decision-making applications related to PoCUS for GRV assessment.

    Methods: This scoping review will follow the JBI Collaboration methodology and will be reported in accordance with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols extension for Scoping Reviews) guidelines. The PCC (population, concept, and context) mnemonic guided the formulation of the research question. Systematic searches will be conducted in MEDLINE, CINAHL, Embase, Scopus, Cochrane Library, and LILACS, as well as in gray literature sources. Eligible sources will include primary studies, reviews, and clinical guidelines focused on PoCUS for GRV assessment in adults (aged ≥18 years). Two independent reviewers will perform study screening and data extraction. The synthesis will be structured using the I-AIM (indication, acquisition, interpretation, and medical decision-making) framework. Results will be summarized narratively, in tables, and through visual representations such as flowcharts and conceptual diagrams.

    Results: This protocol was registered on the Open Science Framework registry on August 21, 2025. The literature search began on April 3, 2026, with study selection and data extraction planned for May 2026. The final results are expected to be submitted for publication in July 2026. As this is a protocol study, no results are available yet.

    Conclusions: This review will identify and categorize the procedures, technical parameters, and clinical applications of PoCUS for GRV assessment in adult patients. By mapping the existing evidence, the findings may inform future research, educational curricula, and the development of clinical guidelines for nurses. In addition, the review will highlight methodological gaps and variations in practice that may affect the safe and effective use of PoCUS across diverse health care settings.

    Trial Registration: OSF Registry CQ8S3; https://osf.io/cq8s3/overview

    International Registered Report Identifier (IRRID): PRR1-10.2196/84080

    JMIR Res Protoc 2026;15:e84080

    doi:10.2196/84080

    Keywords

    point-of-care ultrasonography; gastric residual volume; scoping review; pulmonary aspiration; I-AIM framework 


    Pulmonary aspiration, defined as the entry of oropharyngeal or gastric contents into the lower airways [1], is a serious complication that can lead to aspiration pneumonia and other potentially fatal conditions [2-4]. Older male patients, those with enteral feeding tubes, and those with neurological, gastrointestinal, or pulmonary disorders are at increased risk for this event [4,5]. In anesthetic settings, aspiration of gastric contents is associated with high mortality and permanent injury, particularly when it results from failures in implementing safe practices [6].

    Previous studies have reported an aspiration incidence of 2 to 7 per 20,000 anesthetic procedures, reaching 0.5% in emergency surgeries performed in operating rooms, and rising to 2.7% in emergency procedures performed outside surgical settings [7]. Among patients receiving enteral nutrition, aspiration pneumonia is also common, with prevalence ranging from 4% to 95% and mortality rates from 17% to 62% [5].

    One of the main risk factors for aspiration is elevated gastric residual volume (GRV), which indicates impaired gastrointestinal motility, enteral nutrition intolerance, and delayed gastric emptying [5,8]. These conditions contribute to reflux and vomiting, thereby increasing the risk of pulmonary aspiration, especially in patients with a BMI greater than 30 kg/m2 and in those with type 2 diabetes mellitus undergoing anesthetic induction [5]. Traditional GRV measurement involves active aspiration with a syringe or passive drainage by gravity. However, these techniques are limited by variability in results and a lack of standardization [8,9].

    In this context, point-of-care ultrasound (PoCUS) has emerged as a promising alternative for GRV assessment. PoCUS refers to the use of portable ultrasound performed directly by health care professionals at the bedside for real-time diagnostic or monitoring purposes. It is an objective, focused approach integrated into clinical reasoning that may support faster and safer decision-making in acute and dynamic settings [10].

    For GRV estimation, PoCUS enables assessment of gastric contents by visualizing the gastric antrum in the transverse plane, typically with the patient in the right lateral decubitus position. This structure (Figure 1), located between the left lobe of the liver and the aorta or superior mesenteric artery, can be measured and converted into an estimated volume using validated formulas, such as that proposed by Perlas [11], providing a noninvasive and effective alternative to traditional methods. In addition, this approach may support aspiration risk stratification and improve the safety of enteral nutrition and preoperative fasting [5,8,11,12].

    ‎
    Figure 1. Point-of-care ultrasound (PoCUS) illustration of the gastric antrum.

    A recent study showed that ultrasound examinations performed by nurses in intensive care units for GRV assessment and verification of nasogastric tube position correlated strongly with conventional methods, and were safe, simple, and effective [13]. Although GRV thresholds commonly used to interrupt enteral nutrition range from 200 to 250 mL [14], current American Society for Parenteral and Enteral Nutrition guidelines recommend interrupting enteral nutrition in critically ill patients only when GRV exceeds 500 mL in the absence of other signs of intolerance [15]. Similarly, the European Society for Clinical Nutrition and Metabolism (ESPEN) recommends delaying enteral nutrition in patients with GRV greater than 500 mL, without distinguishing among patient populations [16].

    Despite advances in the clinical use of PoCUS, important gaps remain in the literature regarding the specific techniques used to assess GRV in adults. A preliminary search of PROSPERO, OSF, Web of Science, and the Cochrane Library identified no review protocols on this topic. Moreover, no consolidated guidelines or standardized protocols currently support the safe and effective use of PoCUS by nurses for this purpose. Therefore, this scoping review is proposed to map and synthesize the available evidence on procedures used to assess GRV with PoCUS in adult patients. Specifically, the review aims to identify the clinical indications, image acquisition techniques, sonographic interpretation methods, and medical decision-making application related to GRV estimation using PoCUS across diverse clinical settings. Secondary objectives are as follows:

    • To classify the reported procedural techniques according to the I-AIM framework (indication, acquisition, interpretation, and medical decision-making) framework [17].
    • To identify gaps in the literature regarding standardization and training for PoCUS-based GRV assessment.
    • To inform future guidelines and educational strategies for the safe and effective implementation of PoCUS in nursing and other health care professions.

    Protocol and Registration

    This scoping review will be conducted in accordance with JBI Collaboration methodology [18] and reported in accordance with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines [19].

    The review protocol was registered on the OSF platform [20].

    Research Question

    The Population, Concept, and Context (PCC) mnemonic was used to formulate the research question. Within this framework, the Population (P) comprised adults and older adults (aged ≥18 years), the Concept (C) involves assessment of GRV using PoCUS, and the Context (C) included the various clinical settings in which PoCUS is used for this purpose. Accordingly, the central question guiding this scoping review is as follows: What procedures are used when applying PoCUS to assess gastric residual volume in adult patients across clinical care settings?

    Eligibility Criteria

    Eligible sources will include primary studies, reviews, and clinical guidelines focused on the use of PoCUS for GRV assessment in adult patients (aged ≥18 y). Exclusion criteria will include: (1) studies involving children or animals; (2) abstracts, letters, or expert opinion; (3) protocols and trial registrations; and (4) studies not focused on the stomach (eg, ultrasound of other organs). No date or language restrictions will be applied.

    Information Sources

    Systematic searches will be conducted in the following databases: PubMed (via National Institutes of Health), CINAHL (via EBSCOhost), Embase (via Elsevier), Scopus (via Elsevier), the Cochrane Library (via Wiley), LILACS (via the Virtual Health Library, in Portuguese, Biblioteca Virtual de Saúde), and Web of Science Core Collection (via Clarivate). Gray literature will be searched through OpenAlex, ProQuest Dissertations & Theses Global (via Clarivate), and institutional websites. To ensure comprehensive identification of relevant evidence, additional search strategies will also be used. Specifically, backward citation tracking will be conducted by manually screening the reference lists of all included studies, reviews, and guidelines to identify additional eligible sources that may not have been retrieved in the initial database search.

    Search Strategy

    The search strategy was developed to address the research question using the PCC framework by combining MeSH (Medical Subject Headings) terms and Health Sciences Descriptors in Portuguese (Descritores em Ciências da Saúde) descriptors with relevant keywords and synonyms (Table 1 and Multimedia Appendix 1). Terms were refined using Boolean operators. The initial search was conducted in PubMed.

    Table 1. Population, concept, and context (PCC) framework applied to the research question and search terms.
    PCC elementsDescriptionSearch terms used
    PopulationAdults and older adults (aged ≥18 years)(“Adult”[MeSH Terms] AND “Aged”[MeSH Terms])
    ConceptAssessment of GRVa using PoCUSb(Ultrasound OR Ultrasonography OR “Diagnostic Ultrasounds” OR “Ultrasound Imaging” OR “Bedside Test” OR “Bedside Testing” OR “Bedside Technology” OR “Bedside Technologies” OR “Point of Care” OR “Point-of-Care” OR “Point of Care Systems” OR “Point-of-Care Systems” OR “Point-of-Care System” OR “Point of Care System” OR “Point of Care Technology” OR “Point-of-Care Technology” OR “Point of Care Testing” OR POCUS OR “Point-of-care ultrasonography” OR “Point of care ultrasonography” OR “Point-Of-Care Ultrasound” OR “Point Of Care Ultrasound” OR Sonography OR Ultrasonic* OR ultrasso* AND “Gastrointestinal Contents” OR “Gastric Residual Volume” OR “residual gastric volume” OR “gastric volume” OR “gastric content” OR “Gastric residuals” OR antrum OR “antral area”) AND (assess* OR Evaluation OR avalia*)
    ContextAny clinical settings where PoCUS is used for GRV assessmentPerioperative care, intensive care, emergency, anesthesia, critical care, and others.

    aGRV: gastric residual volume.

    bPoCUS: point-of-care ultrasound.

    A search validation procedure was also used. A set of known key studies relevant to the use of PoCUS for GRV assessment in adult patients was identified in advance by the review team based on prior knowledge and preliminary exploration of the literature (Multimedia Appendix 2 [11,21,22]). These studies served as benchmark references to validate the comprehensiveness and sensitivity of the search strategy. The initial search was tested to ensure the retrieval of these benchmark studies. If any benchmark studies were not retrieved, the search strategy was refined accordingly by adjusting keywords, controlled vocabulary (eg, MeSH terms and Descritores em Ciências da Saúde), and Boolean operators until all key studies were successfully captured.

    For the purposes of this scoping review, PoCUS was defined as the use of portable ultrasound performed directly by a health care provider at the point of care, for real-time diagnostic or clinical monitoring purposes [23]. Gastric residual volume is widely recognized as a surrogate parameter for identifying gastrointestinal motility disorders, particularly delayed gastric emptying. Its measurement has traditionally been used in clinical practice as an indirect indicator of enteral nutrition intolerance and increased risk of complications such as pulmonary aspiration [24].

    Screening and Selection Process of Included Studies

    Search results will be imported into Rayyan for deduplication and blinded screening. Two reviewers will independently screen titles and abstracts, followed by full-text screening, and any disagreement will be resolved by a third reviewer. Reasons for full-text exclusion will be recorded and reported in a PRISMA-ScR flow diagram [19].

    Study authors will be contacted when clarification is needed regarding study eligibility, missing or unclear methodological details, or incomplete data relevant to the review objectives. Initial contact will be made by email using a standardized message template adapted from the OSF repository [25]. Authors will be given two weeks to respond. If no reply is received, a single follow-up message will be sent.

    Consultation with content experts in clinical nutrition, PoCUS, and nursing will be undertaken to identify unpublished data, practice guidelines, or ongoing research that may contribute to the review will also be performed.

    Data Items and Extraction Process

    A customized data charting form, adapted from the JBI template [26], will be used. Two reviewers will independently extract data, followed by reconciliation. Pilot extraction will be conducted on a sample of studies to refine the form and ensure consistency. Extracted data will include the following:

    • Bibliographic information; title, authors, year, and country
    • Study characteristics; design, setting, sample, and operator profession
    • Alignment of PoCUS procedures with I-AIM [17], including
      • indication (clinical context for GRV assessment)
      • acquisition (patient positioning, transducer type, scanning windows, and ultrasound settings)
      • interpretation (sonographic markers, grading scales, and formulas)
      • medical decision-making (use of findings to adjust care, eg, feeding, fasting, and aspiration risk)
    • Other information; training protocols, facilitators or barriers, and guideline recommendations

    Incomplete or partially reported data will not be used as exclusion criteria. Data will be extracted as reported, and missing information will be coded as “not reported” in the extraction tables. No imputation will be performed. The extent and patterns of missing reporting will be described narratively and summarized in tables to enhance transparency and allow readers to interpret the evidence map appropriately.

    Data Synthesis

    The analysis will include both quantitative descriptive summaries and qualitative synthesis. Quantitative data will be summarized using descriptive statistics, including frequencies, proportions, ranges, and measures of central tendency when applicable. Because of substantial heterogeneity in study designs, outcome measures, and reporting formats, no meta-analysis is planned. Heterogeneous measures (eg, different GRV thresholds, measurement techniques, and patient positioning) will be grouped and presented in structured tables to allow comparison across studies.

    For the qualitative synthesis, a thematic analysis approach will be used. Extracted data will be coded inductively and organized into categories aligned with the I-AIM framework domains: indication, acquisition, interpretation, and medical decision-making. Two reviewers will independently code the extracted data. Disagreements will be resolved through discussion, and when consensus cannot be reached, a third reviewer will be consulted.

    The I-AIM framework will be operationalized as an analytic matrix during both data extraction and synthesis. Each included study will be mapped according to the following:

    • Indication; clinical contexts and purposes for GRV assessment using PoCUS
    • Acquisition; technical procedures, equipment, patient positioning, and operator-related aspects
    • Interpretation; criteria used to estimate GRV and define intolerance risk
    • Medical decision-making: how PoCUS findings informed clinical management

    Findings will be synthesized narratively and presented in tables and visual diagrams to identify patterns, variations, and evidence gaps across studies.

    No risk-of-bias appraisal and no meta-analysis are planned, in line with JBI methodological guidance for scoping reviews. The findings will therefore be synthesized using narrative description and structured tabular presentation only.


    This scoping review protocol was registered in the OSF on August 21, 2025, and received funding on August 8, 2025 (process number 305617/2024‐9), and February 6, 2026 (process number 2025/21327‐5). The literature search began on April 3, 2026. Screening and data extraction will occur in May 2026. Data analysis has not yet begun, and the synthesis of results is expected to be finalized by June 2026. The final manuscript is expected to be submitted for publication in July 2026.


    Overview

    This protocol outlines a structured approach to systematically map how PoCUS has been used to assess GRV in adult patients. Its anticipated main contribution is the identification and organization of procedural techniques, interpretation criteria, and clinical decision-making applications across different care settings. Although results are not yet available, this review is expected to provide an integrated overview of how PoCUS for GRV assessment is currently described and operationalized in the literature, while also highlighting areas of variability, gaps, and emerging practices.

    Principal Expected Contributions

    The primary anticipated contribution of this scoping review is the development of a comprehensive map of how PoCUS has been applied to assess GRV, structured according to the I-AIM framework domains: indication, acquisition, interpretation, and medical decision-making [11]. By organizing the evidence in this way, the review is expected to clarify how technical procedures are reported, which clinical contexts most commonly support their use, and how findings are incorporated into care decisions such as enteral nutrition management and aspiration risk assessment. This structured synthesis may help to reduce conceptual fragmentation and provide a clearer reference for clinical and research.

    Comparison With Existing Knowledge

    Existing literature suggests growing interest in PoCUS as a noninvasive bedside method for evaluating gastric contents and supporting clinical decision-making. However, descriptions of procedural details, measurement approaches, and interpretation thresholds appear to be dispersed across disciplines and clinical contexts [12,27,28]. The anticipated findings of this review are expected to extend previous narrative and empirical work by systematically compiling how these procedures are operationalized, rather than focusing exclusively on effectiveness. This may help identify inconsistencies in terminology, heterogeneity in acquisition techniques, and differences in how PoCUS findings are translated into clinical actions.

    Strengths and Limitations

    This protocol has several methodological strengths. It follows JBI methodology for scoping reviews, applies the PRISMA-ScR reporting framework, and includes a comprehensive search strategy across multiple databases and gray literature sources. The use of the I-AIM framework [11] as an analytic structure is expected to support a consistent, theory-informed synthesis of heterogeneous data.

    Future Directions and Implications

    By identifying gaps in procedural reporting, training approaches, and clinical integration, this review is expected to inform future research priorities, including the need for standardized protocols and competency frameworks. The findings may also support the development of educational strategies and guide future validation studies focused on reliability, implementation, and clinical outcomes associated with PoCUS-based GRV assessment.

    Dissemination Plan

    The results of this review will be disseminated through peer-reviewed publications, conference presentations, and the sharing of extracted datasets and synthesis materials via the OSF platform. These strategies aim to promote transparency, facilitate knowledge translation, and support the incorporation of evidence into clinical education and practice, particularly in multidisciplinary and nursing-led care settings.

    Conclusions

    This protocol describes a systematic and transparent approach to mapping the available evidence on the use of PoCUS for GRV assessment in adult patients. By organizing the literature according to procedural domains and clinical applications, the planned review aims to clarify how this technique is currently used, identify areas of variation, and highlight gaps that may guide future research and practice development. As a scoping review protocol, the study does not seek to determine effectiveness but rather to provide a structured overview that may support future standardization efforts, training initiatives, and evidence-informed integration of PoCUS into clinical care.

    Acknowledgments

    We used the generative AI tool ChatGPT (OpenAI) to improve the clarity, grammar, readability, and organization of text drafted by the authors. The authors confirm that generative AI was not used to develop scientific ideas, interpret data, formulate research hypotheses, select or analyze the literature, draw conclusions, or make substantive intellectual contributions to the manuscript. All content, revisions, and final wording were reviewed, edited, and approved by the authors. The authors retain full responsibility for the scientific content, accuracy, and integrity of the manuscript.

    Funding

    This study is supported by the National Council for Scientific and Technological Development, under Call 18/2024 – Research Productivity Fellowship (grant 305617/2024-9), and by the São Paulo Research Foundation (Fundação de Amparo à Pesquisa do Estado de São Paulo [FAPESP]), Scientific Initiation Scholarship (grant 2025/21327-5).

    Data Availability

    The full review protocol, including the search strategies and supporting documents, is publicly available on the Open Science Framework [23]. The datasets generated or analyzed during this study are available from the corresponding author on reasonable request.

    Conflicts of Interest

    None declared.

    Multimedia Appendix 1

    Search strategy and results.

    DOCX File, 12 KB

    Multimedia Appendix 2

    Key papers.

    DOCX File, 12 KB
    1. Herdman TH, Kamitsuru S, Lopes CT. NANDA-I International Nursing Diagnoses: Definitions & Classification, 2024-2026. 13th ed. Thieme Medical Publishers; 2024. ISBN: 9781684206025
    2. Gupte T, Knack A, Cramer JD. Mortality from aspiration pneumonia: incidence, trends, and risk factors. Dysphagia. Dec 2022;37(6):1493-1500. [CrossRef] [Medline]
    3. Shin D, Lebovic G, Lin RJ. In-hospital mortality for aspiration pneumonia in a tertiary teaching hospital: a retrospective cohort review from 2008 to 2018. J Otolaryngol Head Neck Surg. Mar 7, 2023;52(1):23. [CrossRef] [Medline]
    4. Lidetu T, Muluneh EK, Wassie GT. Incidence and predictors of aspiration pneumonia among stroke patients in Western Amhara region, North-West Ethiopia: a retrospective follow up study. Int J Gen Med. 2023;16:1303-1315. [CrossRef] [Medline]
    5. Elmahdi A, Eisa M, Omer E. Aspiration pneumonia in enteral feeding: a review on risks and prevention. Nutr Clin Pract. Dec 2023;38(6):1247-1252. [CrossRef] [Medline]
    6. Warner MA, Meyerhoff KL, Warner ME, Posner KL, Stephens L, Domino KB. Pulmonary aspiration of gastric contents: a closed claims analysis. Anesthesiology. Aug 1, 2021;135(2):284-291. [CrossRef] [Medline]
    7. Zdravkovic M, Berger-Estilita J, Kovacec JW, Sorbello M, Mekis D. A way forward in pulmonary aspiration incidence reduction: ultrasound, mathematics, and worldwide data collection. Braz J Anesthesiol. 2023;73(3):301-304. [CrossRef] [Medline]
    8. Chaitra TS, Palta S, Saroa R, Jindal S, Jain A. Assessment of residual gastric volume using point-of-care ultrasonography in adult patients who underwent elective surgery. Ultrasound J. Feb 8, 2023;15(1):7. [CrossRef] [Medline]
    9. Lindner M, Padar M, Mändul M, et al. Current practice of gastric residual volume measurements and related outcomes of critically ill patients: a secondary analysis of the intestinal-specific organ function assessment study. JPEN J Parenter Enteral Nutr. Jul 2023;47(5):614-623. [CrossRef] [Medline]
    10. Ultrasound guidelines: emergency, point-of-care and clinical ultrasound guidelines in medicine. Ann Emerg Med. May 2017;69(5):e27-e54. [CrossRef] [Medline]
    11. Perlas A, Mitsakakis N, Liu L, et al. Validation of a mathematical model for ultrasound assessment of gastric volume by gastroscopic examination. Anesth Analg. Feb 2013;116(2):357-363. [CrossRef] [Medline]
    12. Santos VB, Silva WP, Apablaza MF, Silva TV, Gimenes FR. The use of point-of-care ultrasound in nurses’ clinical practice as a foundation for patient safety. Rev Bras Enferm. Mar 11, 2024;77Suppl 2(Suppl 2):e77suppl0201. [CrossRef] [Medline]
    13. Brotfain E, Erblat A, Luft P, et al. Nurse-performed ultrasound assessment of gastric residual volume and enteral nasogastric tube placement in the general intensive care unit. Intensive Crit Care Nurs. Apr 2022;69:103183. [CrossRef] [Medline]
    14. Metheny NA, Mills AC, Stewart BJ. Monitoring for intolerance to gastric tube feedings: a national survey. Am J Crit Care. Mar 2012;21(2):e33-e40. [CrossRef] [Medline]
    15. Boullata JI, Carrera AL, Harvey L, et al. ASPEN safe practices for enteral nutrition therapy [formula: see text]. JPEN J Parenter Enteral Nutr. Jan 2017;41(1):15-103. [CrossRef] [Medline]
    16. Singer P, Blaser AR, Berger MM, et al. ESPEN guideline on clinical nutrition in the intensive care unit. Clin Nutr. Feb 2019;38(1):48-79. [CrossRef] [Medline]
    17. Perlas A, Van de Putte P, Van Houwe P, Chan VWS. I-AIM framework for point-of-care gastric ultrasound. Br J Anaesth. Jan 2016;116(1):7-11. [CrossRef] [Medline]
    18. Aromataris E, Lockwood C, Porritt K, Pilla B, Jordan Z. JBI Manual for Evidence Synthesis. JBI; 2024. [CrossRef]
    19. Tricco AC, Lillie E, Zarin W, et al. PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med. Oct 2, 2018;169(7):467-473. [CrossRef] [Medline]
    20. Gimenes FR, Lopes RP, Framartino MD, Pereira RA, Rocha PR, Santos VB. Point-of-care ultrasound in the assessment of gastric residual volume: a protocol of scoping review. JMIR Res Protoc. Preprint posted online on Sep 15, 2025. [CrossRef]
    21. Perlas A, Chan VWS, Lupu CM, Mitsakakis N, Hanbidge A. Ultrasound assessment of gastric content and volume. Anesthesiology. Jul 2009;111(1):82-89. [CrossRef] [Medline]
    22. Perlas A, Davis L, Khan M, Mitsakakis N, Chan VWS. Gastric sonography in the fasted surgical patient: a prospective descriptive study. Anesth Analg. Jul 2011;113(1):93-97. [CrossRef] [Medline]
    23. Blaivas M. A new point of care ultrasound journal. Crit Ultrasound J. Oct 2009;1:1-2. [CrossRef]
    24. Elke G, Felbinger TW, Heyland DK. Gastric residual volume in critically ill patients: a dead marker or still alive? Nutr Clin Pract. Feb 2015;30(1):59-71. [CrossRef] [Medline]
    25. Meta-analysis templates and materials. OSF. URL: https://osf.io/q8stz/ [Accessed 2026-04-20]
    26. Aromataris E, Lockwood C, Porritt K, Pilla B, Jordan Z. Appendix 3.3: JBI qualitative data extraction tool. In: JBI Manual for Evidence Synthesis. JBI; 2024:111. [CrossRef]
    27. Abrokwa SK, Ruby LC, Heuvelings CC, Bélard S. Task shifting for point of care ultrasound in primary healthcare in low- and middle-income countries-a systematic review. EClinicalMedicine. Mar 2022;45:101333. [CrossRef] [Medline]
    28. Shaddock L, Smith T. Potential for use of portable ultrasound devices in rural and remote settings in Australia and other developed countries: a systematic review. J Multidiscip Healthc. 2022;15:605-625. [CrossRef] [Medline]

    ‎
    GRV: gastric residual volume
    I-AIM: indication, acquisition, interpretation, and medical decision-making
    MeSH: Medical Subject Headings
    PCC: population, concept, and context
    PoCUS: point-of-care ultrasound
    PRISMA-ScR: Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews

    Edited by Javad Sarvestan; submitted 15.Sep.2025; peer-reviewed by Ahmed Ramzi; final revised version received 26.Feb.2026; accepted 27.Feb.2026; published 27.Apr.2026.

    Copyright

    © Fernanda Raphael Escobar Gimenes, Renata Pinheiro Lopes, Mariana de Magalhaes Framartino, Rosana Aparecida Pereira, Priscilla Roberta Silva Rocha, Vinicius Batista Santos. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 27.Apr.2026.

    This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Research Protocols, is properly cited. The complete bibliographic information, a link to the original publication on https://www.researchprotocols.org, as well as this copyright and license information must be included.