Preoperative drug histories are built around what patients take for illness. A GLP-1 receptor agonist taken for weight, often bought privately and injected once a week, does not feel to the patient like a medicine you need to know about — so it goes unmentioned unless asked for by name and by indication. The same is true of the patient whose diabetes drug was quietly switched.
These agents slow gastric emptying, and a standard fast does not reliably empty the stomach of someone taking one. The clinically useful stance is not a blanket policy but a change in the history: ask specifically about weekly injections for weight or diabetes, and ask when the last dose was. Then let the answer drive the plan — a longer clear fluid fast, a gastric scan where you have the skill, a rapid sequence induction where the case is urgent, and a frank conversation about postponing an elective case that could safely wait.
The patients most likely to be missed are the ones least likely to be asked: adolescents, and adults who obtained the drug outside their usual care. Add the question to your preoperative form rather than relying on remembering it, because the cost of the omission is an aspiration in a patient who was, by the chart, appropriately fasted.
- Ask by name about weekly injections for weight or diabetes; 'any other medicines' does not surface them.
- Record the date of the last dose, not just the fact of the drug.
- Consider gastric ultrasound where you have the skill and the answer would change the plan.
- Ask adolescents and their carers directly — these drugs are licensed in this age group and easily missed.
- Add the question to the preoperative form; memory is not a system.
The statistics, in plain English
Fasting guidelines rest on the assumption of normal gastric emptying, so a drug that slows emptying invalidates the rule rather than lengthening it — which is why 'fast for longer' is not a complete answer and direct assessment is preferred where available. The risk here is not that the guideline is wrong but that it is being applied to a population it was not derived from.
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