New GLP-1 guidance urges longer fasting before anesthesia

Editor's Note

Patients taking GLP-1 receptor agonists (GLP-1 RAs) do not need to discontinue these medications before undergoing anesthesia but should follow extended preoperative fasting protocols to reduce aspiration risk, according to a June 5 article in Medscape. As detailed in the article, this recommendation comes from a new multidisciplinary consensus statement led by the Society for Perioperative Assessment and Quality Improvement and endorsed by the American Association of Clinical Endocrinology.

Authors note this is the first guidance based on a systematic literature review of both perioperative clinical studies and gastric emptying data. Published in the British Journal of Anaesthesia, the consensus advises patients without significant gastrointestinal symptoms to fast from solid foods for 24 hours. Patients should also avoid high-glucose clear liquids (10% glucose or more) for eight hours and stop all liquid intake four hours prior to the procedure. Both inpatients and outpatients can resume GLP-1 RAs upon return to their usual diet. The authors recommend that patients with severe gastrointestinal symptoms postpone elective procedures and consult with their prescribing physician for management.

The Medscape article reviews earlier guidance issued by the American Society of Anesthesiologists (ASA) in June 2023, which recommended holding GLP-1 RAs for one half-life due to concerns about aspiration events, though such events were rare. At that time, standard ASA fasting guidelines—eight hours after a full meal—remained in place. The new consensus states that halting GLP-1 RAs for a single half-life is insufficient to reverse delayed gastric emptying, especially with long-acting drugs like dulaglutide, semaglutide, and tirzepatide.

According to Medscape, discontinuing these medications for several weeks may be required to normalize gastric motility. However, doing so in patients with type 2 diabetes could impair glycemic control, a factor linked to poorer postoperative outcomes. For patients using GLP-1 RAs for weight loss, stopping and restarting the medications may lead to gastrointestinal side effects or necessitate gradual dose reescalation, which can be logistically difficult.

The article notes that updated guidance issued in October 2024 by ASA and other professional societies allowed GLP-1 RA continuation in patients without elevated risk. Patients at higher risk were defined as those in the escalation phase, on higher doses or weekly dosing, and with active gastrointestinal symptoms. These patients were advised to follow a 24-hour liquid diet. However, some experts questioned this stratification, citing a lack of evidence correlating dose regimen or treatment phase with increased gastric content, and noted that the absence of symptoms does not guarantee gastric emptying.