Semaglutide and Preoperative Residual Gastric Volumes

Given the pharmacodynamic and pharmacokinetic properties of glucagon-like peptide-1 (GLP-1) agonists, the Canadian Anesthesiologists' Society has recognized that patients on GLP-1 agonists may have an increased aspiration risk due to a 'full stomach,' even after following preoperative fasting guidelines. In other words, safe fasting timelines are not known in individuals taking GLP-1 agonists, as demonstrated by recent case reports of patients who either retained or regurgitated stomach contents despite being adequately fasted.

To address this gap, we plan to measure preoperative residual gastric volumes with point-of-care ultrasound (POCUS) in patients taking this medication. The priority is to first gather data to identify which patient populations need risk stratification and to then use this data to support the development of specific guidelines that reduce anesthetic complications, such as aspiration pneumonia.

Our primary objective is to use POCUS preoperatively to assess gastric volumes of fasted patients to demonstrate if there is a clinically significant increase in residual gastric volumes in patients on semaglutide.