Gastric ultrasound in patients receiving semaglutide: a prospective, multicentre, matched control study

Delayed gastric emptying is a known effect of glucagon-like peptide-1 receptor agonists, such as semaglutide. While tachyphylaxis has been reported, recent clinical data indicate an increased risk of residual gastric content on pre-operative gastric ultrasound in patients who are fasted. However, the limited available data do not control for several important potential confounders.

We conducted a prospective, multicentre, matched case-control study, enrolling patients receiving semaglutide treatment for diabetes mellitus or weight loss and having elective surgery. For each patient receiving semaglutide treatment, we included a matched control based on age, BMI and diabetes mellitus status in a 1:1 ratio. In both cohorts, gastric ultrasound was performed in the supine position, followed by the right lateral decubitus position. A patient was considered to have a 'full stomach' if solid gastric content was visible in any position or if the calculated gastric volume in the right lateral decubitus position exceeded 1.5 ml.kg^-1 of total body weight.

We enrolled 44 patients receiving semaglutide treatment and 44 matched controls. A full stomach was observed in 21/43 (49%) of patients receiving semaglutide treatment compared with 8/44 (18%) of controls (odds ratio 4.29, 95%CI 1.63-11.29, p = 0.003). Solid gastric contents were significantly more frequent in patients receiving semaglutide treatment (18/43 (42%)) compared with controls (3/44 (7%), odds ratio 9.85, 95%CI 2.57-37.76, p < 0.001). Calculated gastric volume did not differ significantly.

This study compared gastric ultrasound findings in patients receiving semaglutide treatment with matched controls, thereby accounting directly for baseline delayed gastric emptying. Our findings highlight a persistently elevated pulmonary aspiration risk, even after withholding one administration of semaglutide and accounting for age, diabetes mellitus status and obesity. Where available, gastric ultrasound should be used to guide individualised anaesthetic management and optimise peri-operative safety.