Nearly half of patients on GLP-1 receptor agonists had significant residual gastric contents before anesthesia, raising concerns about aspiration risk during surgery.
3 hospital sitesMulti-center study assessing gastric contents in GLP-1 RA patients before anesthesia
What the researchers found
A substantial proportion of patients on GLP-1 receptor agonists had high residual gastric contents before anesthesia despite standard fasting, suggesting current preoperative fasting guidelines may be inadequate for this population.
Why it matters
With millions now taking GLP-1 drugs for diabetes and weight loss, the surgical safety implications are enormous. Delayed gastric emptying increases the risk of pulmonary aspiration during anesthesia — a potentially life-threatening complication.
The numbers in context
- 316 patients studied; 35.8% had high residual gastric contents
- Weekly injection withholding: 8 days (low RGC) vs 6 days (high RGC), p=0.003
- Cutoff: 7.5 days of withholding weekly injections
- Solid food fasting: 20 hours (low RGC) vs 15 hours (high RGC), p<0.001
- Cutoff: 21.3 hours fasting from solids
- Opioid use: 5.3% (high RGC) vs 1.0% (low RGC), p=0.027
How the study worked
Prospective cohort study across 3 hospitals. Adult patients taking GLP-1 RAs and scheduled for anesthesia underwent preoperative gastric ultrasound to assess residual gastric contents (RGC). Preoperative factors associated with high RGC were evaluated.
Who was studied
N=316 adults on GLP-1 receptor agonists scheduled for anesthesia at 3 US hospitals, June 2023 to August 2024. Median age 60.9, 52.8% female.
What this study cannot tell us
Sample size and specific prevalence numbers not provided in abstract; ultrasound assessment is operator-dependent; did not directly measure aspiration events, only risk indicators; may not account for all GLP-1 RA types and doses.
How to read the evidence
Prospective multi-center cohort study providing moderate clinical evidence. Directly relevant to patient safety but would benefit from larger randomized studies.
When this study was published
Published in 2025 with data from 2023 onward, reflecting the current era of widespread GLP-1 RA use.
The bigger picture
As GLP-1 receptor agonists become one of the most prescribed drug classes worldwide, this study underscores the urgent need for anesthesiology guidelines to adapt. The findings have implications for the millions of patients on semaglutide, liraglutide, and similar drugs who may need surgery.
Questions still open
- Should patients stop GLP-1 drugs days or weeks before surgery to allow gastric motility to normalize?
- Are certain GLP-1 receptor agonists (weekly vs. daily formulations) associated with greater gastric retention?
- What is the optimal fasting duration for GLP-1 RA users before anesthesia?
Common questions
Should I stop my GLP-1 medication before surgery?
What happens if your stomach isn't empty during surgery?
Read the original research
Assessment of Gastric Content Using Gastric Ultrasound in Patients on Glucagon-Like Peptide-1 Receptor Agonists Before Anesthesia.
Anesthesia and analgesia
Citation
Pai, Sher-Lu; Nimma, Sindhuja R; Beam, W Brian; VanderWielen, Beth A; Kalagara, Hari K; Bettini, Layne M; Yu, Soojie; Sharpe, Emily E; Harbell, Monica W. (2025). Assessment of Gastric Content Using Gastric Ultrasound in Patients on Glucagon-Like Peptide-1 Receptor Agonists Before Anesthesia.. Anesthesia and analgesia. https://doi.org/10.1213/ANE.0000000000007764