GLP-1 and Surgery: The Updated Anesthesia Guidelines Your Surgeon Might Not Know

Why the Old Rule Changed

In June 2023, the American Society of Anesthesiologists (ASA) issued guidance recommending that patients stop daily GLP-1 medications one day before surgery and weekly formulations one full week before. The concern was that GLP-1 drugs delay gastric emptying, potentially leaving food in the stomach that could be aspirated into the lungs during general anesthesia.

That guidance created widespread confusion. Surgeries were delayed. Patients went weeks without their medication. Blood sugar spiked in diabetic patients. And the evidence base for the blanket recommendation was thin.

In October 2024, a new multi-society guidance — co-authored by the ASA, the American Gastroenterological Association, the American Society for Metabolic and Bariatric Surgery, the International Society of Perioperative Care of Patients with Obesity, and the Society of American Gastrointestinal and Endoscopic Surgeons — substantially reversed course.

What the Updated Guidance Actually Says

The 2024 multi-society document takes a risk-based approach rather than a one-size-fits-all rule. It divides patients into risk categories based on their likelihood of having delayed gastric emptying:

Low risk: Patients on a stable GLP-1 dose without significant GI symptoms can continue their medication and proceed with surgery following standard preoperative fasting guidelines.

Elevated risk: Patients who experience active GI symptoms (nausea, vomiting, bloating), are in the dose titration phase, or have other conditions that slow gastric emptying (like Parkinson's disease) should follow additional precautions — typically a liquid diet for 24 hours before the procedure.

Highest risk: In rare cases where the risk is expected to decrease with time, the procedure may be delayed. But the guidance explicitly states that withholding GLP-1 medication should be balanced against the metabolic risks — including blood sugar spikes in diabetic patients and the cost or insurance barriers to restarting medication.

Why Your Surgeon May Still Use the Old Rule

Medical guidelines update faster than surgical practice. Many surgeons and anesthesiologists still operate under the 2023 ASA recommendation, either because they haven't reviewed the October 2024 update or because their institution hasn't revised its protocols.

The guidance also notes an important equity concern: withholding GLP-1 medications only for patients with obesity or overweight could constitute bias or discrimination and should be avoided. This was a notable addition that wasn't in the 2023 guidance.

What to Do If You Have Surgery Scheduled

If you're on a GLP-1 medication and have an upcoming elective surgery, take these steps:

Notify your surgical team early. Don't wait until the pre-op appointment. Let your surgeon and anesthesiologist know which GLP-1 medication you take, what dose, and how long you've been on it.

Reference the 2024 guidance. If your surgeon asks you to stop your medication a week before surgery, you can respectfully ask whether they've reviewed the October 2024 multi-society clinical practice guidance. The paper was published in Clinical Gastroenterology and Hepatology, Surgery for Obesity and Related Diseases, and Anesthesiology simultaneously.

Report your GI symptom history honestly. The risk assessment depends on whether you're experiencing active nausea, vomiting, or bloating. If you're on a stable dose with no GI issues, you're in the low-risk category.

Follow the liquid diet if recommended. If your care team recommends a 24-hour liquid diet before surgery, take that seriously. Clear liquids, broth, protein shakes without fiber — nothing solid.

Emergency Surgery Is Different

The guidance above applies to elective (planned) procedures. In emergency situations, the surgical team will assess aspiration risk in real time using point-of-care gastric ultrasound when available. If significant gastric contents are found, rapid-sequence intubation protocols reduce aspiration risk.

The Takeaway

The science has evolved. The blanket "stop a week before surgery" rule is no longer the standard of care. A risk-based, individualized approach — with shared decision-making between you, your prescriber, your surgeon, and your anesthesiologist — is what the current evidence supports. Advocate for that conversation.