Fact-check: the Anesthesia Patient Safety Foundation on GLP-1s before anaesthesia

What the video covers

APSF's podcast revisits two earlier episodes on an October 2023 newsletter article by Mayo Clinic anaesthesiologists. Two cases: a patient on semaglutide for a month, last dose seven days earlier, fasted more than 18 hours, with solid food seen on gastric ultrasound and the sedation cancelled; and a patient on tirzepatide, last dose two days earlier, presenting for surgery. The episode then reads through the June 2023 American Society of Anesthesiologists consensus guidance and ends with one author's view that fasting rules, a clear-liquid period and routine gastric ultrasound may be better tools than holding a drug with a one-week half-life.

What it gets right

The pharmacology is correct: GLP-1 receptor agonists delay gastric emptying, semaglutide's half-life is about a week, so withholding for five half-lives is impractical, and aspiration is among the top three airway-related adverse events in the ASA closed-claims data. The ASA guidance is summarised accurately: for elective procedures, hold daily agents on the day and weekly agents one week before, regardless of indication; on the day, delay if there are GI symptoms; if the drug was not held, treat as full stomach or check gastric volume by ultrasound; do not delay urgent surgery. The episode is equally clear that the evidence base was case reports and that the optimal fasting duration was unknown.

The Wegovy and Zepbound labels have since added language about delayed gastric emptying and aspiration under anaesthesia, which confirms the concern the article raised.

What it leaves out or overstates

The main gap is what happened afterward. In October 2024 the ASA, the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery and others issued joint guidance that most patients can continue their GLP-1 through the perioperative period, and that those at elevated risk of retained contents (escalation phase, higher doses, weekly dosing, GI symptoms, other conditions slowing the gut) should follow a liquid diet for 24 hours before the procedure, with gastric ultrasound where symptoms persist (PubMed 39482213). That is a different default from "hold for a week", and it is closer to the closing opinion in this episode than to the guidance the episode reads out. Anyone acting on this video should know that both documents exist and that institutions vary.

The episode also cannot tell you how often retained contents actually occur. Studies since have found increased residual gastric content on ultrasound in GLP-1 users, but aspiration events remain rare, and the balance between that risk and the harm of stopping a diabetes drug is why the 2024 guidance moved.

Where to go next

Surgery and anaesthesia planning, including the label aspiration language and what to tell the team, has its own guide on FormBlends Guides. The missed-dose helpers on the Semaglutide Hub and Tirzepatide Hub cover restarting after a planned hold, per label. FormBlends dispenses compounded GLP-1s (formblends.com); they are not FDA approved and the same gastric effects apply.