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

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.

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.

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.

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.

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.