Ultrasound assessment of preoperative gastric volume in fasted diabetic surgical patients: A prospective observational cohort study on the effects of glucagon-like peptide-1 agonists on gastric emptying

Preoperative gastric ultrasound allows non-invasive qualitative and quantitative assessment of gastric contents aiding in preoperative risk assessment. We hypothesized that appropriately fasted diabetic surgical patients taking GLP-1 agonists would have higher gastric volumes than those not taking GLP-1 agonists. This prospective, observational cohort study enrolled diabetic patients undergoing elective surgery, comparing those taking (n = 106) and not taking (n = 100) GLP-1 agonists. The primary outcome was gastric volume assessed via gastric ultrasound in the right lateral decubitus position. Secondary outcomes included presence of a full stomach (solids/thick liquids or greater than 1.5 mL/kg clear liquid), need for surgery delay, Perlas grade, and occurrence of intraoperative aspiration. The impact of GLP-1 agonist type, duration of use, and timing of last dose on gastric volume was also examined. Diabetic patients on GLP-1 agonists had significantly higher median gastric volumes compared to patients not on GLP-1 agonists (0.61 mL/kg vs 0.16 mL/kg, P < 0.001) and increased odds of a full stomach (OR 11.3, 95 % CI 5.2-24.7, P < 0.0001). GLP-1 agonist use correlated with higher Perlas grades (P < 0.001). Gastric volumes were significantly higher with GLP-1 agonist use within 7 days of surgery relative to use within 7-14 days or more than 14 days from surgery (P < 0.001 for both comparisons). GLP-1 agonist therapy was associated with higher residual gastric volumes and higher risks of full stomachs in fasted diabetic patients. GLP-1 agonist use within 7 days of surgery was also associated with higher gastric volumes relative to holding therapy for over 7 days, supporting current consensus-based guidelines.