A patient of mine had a knee replacement postponed on the morning of surgery because the pre-op questionnaire asked about diabetes medication and she does not have diabetes, so she said no. She was on Zepbound. Nobody asked the right question, and she lost a theatre slot she had waited five months for.
This is now one of the more common perioperative conversations in American medicine, and the guidance underneath it moved recently enough that a lot of printed instructions are out of date.
Why this became an issue at all
Anaesthesia removes the reflexes that keep stomach contents out of your airway. The entire ritual of pre-operative fasting exists to make sure there is nothing there to aspirate.
That ritual assumes a normal emptying rate. These drugs break the assumption. Gastric ultrasound studies have repeatedly found solid residue in the stomachs of GLP-1 users who had fasted correctly — people who did everything they were told and still arrived with a full stomach.
Aspiration is not common. It is, however, one of the more feared complications in anaesthetic practice, and the specialty responded quickly.
What the 2023 guidance said
The American Society of Anesthesiologists issued consensus advice in June 2023:
- Hold daily GLP-1 agonists on the day of the procedure
- Hold weekly GLP-1 agonists for one week before the procedure
- If symptoms of delayed emptying are present on the day, consider delaying or treating the patient as a full stomach
Clean, memorable, and widely adopted. It is still what most pre-op letters say.
What changed in 2024
The problem with a one-week hold is that it is not free. Skipping a week destabilises glycaemic control in people with diabetes, interrupts titration, and — for a class where consistency matters — creates a fortnight of disruption around a procedure that might take twenty minutes.
A multi-society panel, including anaesthesiology, bariatric surgery and gastroenterology bodies, published revised guidance in 2024 that moved to a risk-stratified approach:
- Continue the medication in many patients rather than reflexively stopping
- Place greater weight on a 24-hour clear liquid diet before the procedure, which addresses the actual problem more directly than a week without drug
- Stratify by risk: recent dose escalation, high dose, active GI symptoms, and diabetes with autonomic neuropathy all push toward more caution
- Use gastric ultrasound where available to assess the stomach directly rather than guessing
- Reserve withholding for higher-risk cases
What you should actually do
Declare it early, and declare it precisely. The pre-op questionnaire probably asks about diabetes drugs. If you take Wegovy or Zepbound for weight, that question will not catch you. Say the drug name, the dose, and the date of your last injection.
Ask two specific questions. Do you want me to hold it, and for how long? And what should I be eating in the 24 hours beforehand? A pre-op nurse can answer both, and the answers vary by hospital.
Expect the clear liquid instruction. Twenty-four hours of clear fluids before a procedure is doing more work than a week off the drug, and it is increasingly what teams ask for.
Do not stop on your own initiative. If you have diabetes, an unplanned week off can send glucose somewhere unhelpful in the exact week you need to be well.
1 week
Weekly-injection hold recommended by the 2023 ASA consensus
24 hours
Clear liquid diet emphasised by the 2024 multi-society guidance
Day of
Hold period for daily oral GLP-1s such as Rybelsus
Endoscopy is the same problem, more visibly
An upper endoscopy on a stomach containing food is at best an incomplete procedure and at worst an aborted one, and the aspiration risk under sedation is identical. Endoscopy units have become considerably more assertive about asking.
Colonoscopy has the added indignity of an inadequate bowel prep, since slowed transit affects the whole gut, not just the stomach. If you are booked for one, ask whether they want an extended prep.
A week without the drug is not a neutral act. Neither is an anaesthetic on a stomach nobody checked.
The emergency case
None of the above applies to unplanned surgery. In an emergency the anaesthetist manages you as a full stomach — rapid sequence induction, cricoid pressure, whatever their judgement calls for — and the fact that you are on a GLP-1 is one input among many.
Which is the argument for carrying the information on you. A card in your wallet or an entry in your phone’s medical ID stating the drug, the dose and the schedule takes two minutes to set up and answers the question when you cannot.
The short version for your pre-op form
You are on a medication that changes a core assumption of anaesthetic safety. Say so, early, by name.
Everything after that is your surgical team’s problem to solve, and they are good at it once they know.