Fat loss medication linked to surgery risk in new study

Safety concerns have been revealed in a University of Texas Health (UTHealth) Houston study, for patients using glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and going under anaesthesia.

GLP-1 RAs are medications approved for diabetes and weight management, that have recently seen a spike in interest from the public, with celebrities using injectables like semaglutide to maintain and lose weight.

UTHealth Houston revealed its findings in JAMA Surgery, published today, showing a link between GLP-1 RA drugs and potential aspiration risk under anaesthesia.

The study was led by first author Sudipta Sen, associate professor, and senior author Omonele Nwokolo, professor, both in the Department of Anaesthesiology, Critical Care and Pain Medicine at McGovern Medical School at UTHealth Houston.

“Our findings were quite surprising. More than half of the patients on a GLP-1 RA had significant gastric contents on gastric ultrasound before an elective procedure, despite adhering to preoperative fasting,” said Sen: “This incidence was significantly higher compared to patients not on a GLP-1 RA, showing a strong link between GLP-1 RA drugs and potential aspiration risk under anaesthesia.”

Designed by Paul Potnuru, assistant professor, the study examined more than 120 patients scheduled for elective procedures between June and July 2023. Findings revealed that 56% of patients using GLP-1 RAs exhibited increased residual gastric content, compared to 19% of those who did not take the medication. The study further indicated a 30.5% prevalence of increased residual gastric content with the use of GLP-1 RAs.

The study was prompted by internal quality reviews led by Nwokolo and Srikanth Sridhar, associate professor in the department, after anecdotal cases of aspiration under anaesthesia were reported by staff for patients taking this class of medications for weight loss, despite adequate fasting before the procedure.

Sen and study co-authors Nadia Hernandez, associate professor, and Christina Goehl, assistant professor, are subspecialised anaesthesiologists with expertise in point-of-care ultrasound, which allows bedside assessment of stomach contents. One mechanism of GLP-1 RA medications central to weight loss and glycaemic control is slowing of the emptying of gastric contents from the stomach. This increase in residual gastric volumes is identified as a “full stomach” on gastric ultrasound.

McGovern Medical School student Caroline Praestholm, also contributed to the study.
With the increasing use of GLP-1 RA medications, and their expanding indications for treating various conditions, Sen said conventional fasting times for this patient subset may need to be re-examined.
“Patients must ensure they disclose their use of this medication to their surgeons and anesthesiologists,” Sen said. “This information is crucial for us to provide appropriate recommendations, such as adjusting drug administration before elective procedures, recommending extended fasting, or rescheduling an elective procedure if necessary.”