Assessment of Gastric Content Using Gastric Ultrasound in Patients on Glucagon-Like Peptide-1 Receptor Agonists Before Anesthesia

BACKGROUND: The use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has significantly increased in recent years. GLP-1 RAs delay gastric emptying, resulting in early satiety and weight loss. This may increase the risk of pulmonary aspiration of residual gastric contents (RGC) during anesthesia delivery. Evidence is urgently needed to guide perioperative anesthesia management for patients taking GLP-1 RAs. This study evaluated preoperative factors that may be associated with high RGC. METHODS: Adult patients who were taking GLP-1 RAs and scheduled to receive anesthesia at 3 hospitals between June 30, 2023, and August 15, 2024, were evaluated via preoperative point-of-care gastric ultrasonography (GUS). The primary outcome was high RGC, defined by the presence of solids food or >1.5 mL/kg of clear liquids on GUS, and its association with preoperative factors (eg, existing medical conditions, indication and route of taking GLP-1 RAs, length of taking GLP-1 RAs, days of withholding GLP-1 RAs before surgery, and preoperative fasting periods). Data are presented as median (interquartile range [IQR]). RESULTS: Among the 316 patients (60.9 years [52.1-68.9] of age; 167 [52.8%] females) included in the study, 113 (35.8%) had high RGC. A higher percentage (5.3%; 6/113) of patients in the high RGC group had an opioid prescription for pain management within 3 months of the GUS assessment compared to the low RGC group (1.0%; 2/203; P = .027). No statistical difference was found between the groups in other existing medical conditions, indication and route of taking GLP-1 RAs, and length of taking GLP-1 RAs. Of the 294 patients taking weekly injections, there were 187 (63.6%) with low RGC and 107 (36.4%) with high RGC. Patients with low RGC withheld their GLP-1 RAs for 8 days [5-10], while patients with high RGC withheld for 6 days [3-9] ( P = .003). Receiver operating characteristic (ROC) analysis found ≤7.5 days of withholding the medication as cutoff for increased prevalence of high RGC in patients taking GLP-1 RA injections. Patients with low RGC fasted from solid food for 20.0 hours [14.8-40.8], and patients with high RGC fasted from solid food for 15.0 hours [12.8-19.0] ( P < .001). ROC found ≤21.3 hours of fasting from solid food as the cutoff for increased prevalence of high RGC. CONCLUSIONS: GLP-1 RA usage may delay gastric emptying. In preoperatively fasting adults, ≤7.5 days of withholding injections and ≤21.3 hours of fasting from solid food are associated with high RGC.