GASTRIC ULTRASOUND FOR ASPIRATION-RISK STRATIFICATION IN PATIENTS RECEIVING GLP-1 RECEPTOR AGONISTS: AN INTEGRATED SYSTEMATIC REVIEW AND EVIDENCE UPDATE OF ULTRASONOGRAPHIC, ENDOSCOPIC, AND ANESTHETIC OUTCOMES

Abstract

DOI: https://doi.org/10.46296/yc.v10i18.0915

Abstract

Background: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual GLP-1/GIP agonists delay gastric emptying. Observational endoscopy data consistently show more retained gastric content (RGC), but pulmonary aspiration remains rare and the role of gastric ultrasound as an individualized preprocedural triage tool has not been integrateld with endoscopic and anesthetic outcomes. Methods: We performed an integrated systematic review and structured evidence update. The endoscopy evidence base was anchored to a systematic review that searched MEDLINE and the Cochrane Library through 7 July 2025 and included 24 comparative studies. A targeted PubMed/citation update through 27 August 2026 expanded eligibility to gastric-ultrasound studies and newly published endoscopy/anesthesia studies. Adults receiving GLP-1 RA or GLP-1/GIP therapy were eligible when objective gastric content was assessed by ultrasound or upper endoscopy, or when aspiration/anesthetic outcomes were reported. A random-effects exploratory meta-analysis pooled four controlled gastric-ultrasound cohorts with compatible definitions of increased RGC/full stomach. Results: The integrated evidence set comprised 35 primary studies (24 carried forward and 11 newly integrated). The predecessor endoscopy synthesis (184,707 participants) found higher RGC (OR 4.82, 95% CI 3.66-6.35) and procedure discontinuation (OR 3.93, 95% CI 2.42-6.39), without a statistically significant increase in aspiration (OR 1.10, 95% CI 0.84-1.48). In four controlled ultrasound cohorts (n=461), GLP-1 RA exposure was associated with increased RGC/full stomach (pooled crude OR 9.31, 95% CI 3.68-23.57; I²=60.0%). The 2026 OCULUS randomized trial (n=60) found clinically significant residual gastric volume in 25.0% of patients continuing therapy versus 3.1% withholding one dose. No eligible same-patient diagnostic-accuracy study directly validated gastric ultrasound against subsequent EGD findings in GLP-1-treated patients. Conclusions: GLP-1-based therapy is strongly associated with RGC detected by both ultrasound and endoscopy, whereas evidence for increased aspiration is inconsistent and limited by rare events. Gastric ultrasound is a promising individualized risk-stratification adjunct, but its diagnostic agreement with endoscopic findings and its ability to reduce clinically important aspiration events require prospective paired validation.

Keywords: GLP-1 receptor agonist; semaglutide; gastric ultrasound; POCUS; retained gastric content; upper gastrointestinal endoscopy; aspiration; anesthesia; sedation.