GLP-1 receptor agonists before surgery: no excess aspiration in pre-2023 data

Design

Retrospective propensity-matched database cohort (TriNetX)

Population

Adults with type 2 diabetes having surgery, 2013–2023

Primary outcome

14-day mortality, aspiration pneumonitis, pneumonia and cardiovascular events

Effect

Mortality RR 0.44 (0.31 to 0.64) vs metformin; no increase in aspiration

This Anesthesiology analysis, published 25 September, used TriNetX electronic health records from 2013 to 2023 — before the 2023 ASA guidance to hold GLP-1 receptor agonists — to compare adults with type 2 diabetes taking these drugs with propensity-matched patients on metformin, SGLT2 inhibitors or DPP-4 inhibitors, without the comparator drug.

GLP-1 receptor agonist use was associated with lower 14-day mortality than metformin (0.98% vs 2.20%; RR 0.44, 95% CI 0.31 to 0.64) and DPP-4 inhibitors (1.84% vs 2.89%; RR 0.63, 0.45 to 0.89), and with less bacterial pneumonia than DPP-4 inhibitors (RR 0.47). There was no increase in aspiration pneumonitis against any comparator.

This is reassuring about the rare outcome that drove the hold-the-drug advice, but it is a database study with residual confounding and coding limits. It does not show that delayed gastric emptying is harmless, and it does not tell you what to do with the patient in front of you who has symptoms of retained gastric contents.

• Ask every patient on a GLP-1 receptor agonist about nausea, vomiting, bloating and early satiety before induction.
• Follow current local or society guidance on holding GLP-1 receptor agonists; this study does not replace it.
• Use gastric ultrasound where available if there is doubt about gastric contents.
• Treat a symptomatic patient as full-stomach regardless of fasting time.

Why it matters

Questions whether routinely stopping GLP-1 receptor agonists before surgery prevents harm or only disrupts glucose control.

Don't overread it

Observational association from coded records; the lower mortality is very unlikely to be caused by the drug over 14 days.

The statistics, in plain English

A risk ratio of 0.44 for mortality means less than half the risk of dying within 14 days, but in an observational comparison healthier patients may simply have been prescribed GLP-1 receptor agonists.

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