GLP-1 Perioperative Hold Calculator
Compiled by Anthony K C Fong (attorney, not a clinician) from the primary published guidance cited below · Last reviewed:
Decision support for anesthesiologists, CRNAs, and surgical teams managing patients on GLP-1 receptor agonists (semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide). Based on the October 2024 multi-society consensus guidance from ASA, AGA, ASMBS, ISPCOP, and SAGES.
Patient & procedure
Escalation phase carries higher delayed-gastric-emptying risk than maintenance.
Nausea, vomiting, dyspepsia, or abdominal distension.
Recommendation
- →Liquid-only diet for 24 hours preoperatively.
- →Standard NPO guidelines after that.
- →Consider gastric ultrasound if any concern at induction.
- →Standard aspiration prophylaxis.
- →No routine GLP-1 hold required per 2024 multi-society guidance.
2024 Multi-Society Guidance Summary
The 2024 update walked back the 2023 ASA recommendation to hold GLP-1s the day of surgery (weekly) or one week prior (weekly dosing). Most patients should now continue their GLP-1 with risk mitigation, not blanket holding.
- Liquid-only diet 24h before procedure minimizes residual gastric contents in patients on GLP-1s.
- Point-of-care gastric ultrasound right before induction in higher-risk patients (escalation phase, GI symptoms, full stomach concerns).
- Anesthesia plan adjustment: rapid sequence induction, head-up positioning, or awake intubation may be appropriate for highest-risk cases.
- Escalation phase > maintenance phase for delayed gastric emptying risk. Patients still titrating doses are higher-risk.
- Symptoms matter: nausea, vomiting, abdominal distension, or dyspepsia on the day of surgery should prompt reassessment regardless of dose phase.
What changed between the 2023 and 2024 guidance
The original 2023 ASA consensus-based guidance recommended holding GLP-1s the day of surgery for daily dosing, or one week prior for weekly dosing - a blanket precaution against delayed gastric emptying and aspiration risk. That approach drew criticism for lacking a strong evidence base and for causing unnecessary glycemic and metabolic disruption in patients who held their medication without a clear risk-adjusted rationale.
The October 2024 multi-society update - ASA jointly with AGA, ASMBS, ISPCOP, and SAGES - replaced the blanket hold with a risk-stratified approach: continue the medication for most patients, layering in mitigation strategies (liquid-only diet, point-of-care gastric ultrasound, anesthesia plan adjustments) scaled to individual risk factors - dose phase, reported GI symptoms, procedure type - rather than defaulting to a hold for everyone.
Edge cases the calculator doesn't resolve
Endoscopy vs elective major surgery: the underlying mechanism applies across procedure types, but the risk calculus and mitigation options differ. Many endoscopy units have adopted point-of-care gastric ultrasound or a same-day liquid-diet screen as a standard pre-procedure check specifically because of GLP-1 patient volume. Elective major surgery with general anesthesia carries a different risk profile and a correspondingly more conservative approach is common in practice.
Emergency surgery: explicitly outside the scope of elective-surgery risk stratification - there is no time for pre-procedure diet modification. Anesthesia teams generally apply full-stomach precautions (rapid sequence induction, cricoid pressure per institutional protocol) regardless of reported last meal time, since GLP-1-related delayed gastric emptying means standard NPO-time assumptions may not hold.
Frequently asked questions
Why did the guidance change from 2023 to 2024?
The original 2023 ASA consensus-based guidance recommended holding GLP-1s the day of surgery for daily dosing, or one week prior for weekly dosing, largely as a precautionary measure against delayed gastric emptying and aspiration risk. That blanket-hold approach drew criticism for lacking a strong evidence base and for creating unnecessary glycemic and metabolic disruption in patients who held their medication without a clear risk-adjusted rationale. The October 2024 multi-society update (ASA jointly with AGA, ASMBS, ISPCOP, and SAGES) replaced the blanket hold with a risk-stratified approach: continue the medication for most patients, and layer in mitigation strategies (liquid-only diet, point-of-care gastric ultrasound, anesthesia plan adjustments) scaled to individual risk factors rather than defaulting to a hold.
Does the same guidance apply to endoscopy as to major elective surgery?
The underlying mechanism - delayed gastric emptying increasing aspiration risk under sedation - applies across procedure types, but the risk calculus and the practical mitigation options differ. Endoscopy typically involves lighter sedation than general anesthesia for major surgery, and many endoscopy units have incorporated point-of-care gastric ultrasound or a same-day liquid-diet screen as a standard pre-procedure check specifically because of the volume of GLP-1 patients now presenting for routine colonoscopy and upper endoscopy. Elective major surgery with general anesthesia carries a different risk profile (longer NPO windows are harder to guarantee compliance with, induction itself is a higher-risk moment for aspiration) and a correspondingly more conservative approach - including a lower threshold for the liquid-only 24-hour pre-procedure diet - is common in practice, even though the 2024 consensus guidance does not draw a hard categorical line between the two.
What about emergency surgery where there is no time for a liquid-only diet?
Emergency surgery is explicitly outside the scope of elective-surgery risk stratification - there is no time to implement a pre-procedure diet modification or plan a delayed induction. In practice, anesthesia teams treat a patient on a GLP-1 presenting for emergency surgery similarly to any full-stomach precaution case: rapid sequence induction, cricoid pressure per institutional protocol, and heightened aspiration-risk awareness regardless of the patient's reported last meal time, since GLP-1-related delayed gastric emptying means standard NPO-time assumptions may not hold. This is an institution-specific protocol decision, not something a risk calculator can substitute for - the tool above is designed for elective-procedure planning, not emergency intraoperative decision-making.
Does dose phase (escalation vs maintenance) actually change the risk meaningfully?
Yes, and it is one of the more consistently cited risk factors in the 2024 guidance and subsequent case-series literature. Gastric emptying delay tends to be most pronounced during the escalation phase of GLP-1 dosing - typically the first several weeks after any dose increase - before some degree of tachyphylaxis (reduced drug effect with continued exposure) develops at a stable maintenance dose. A patient who has been stable at their maintenance dose for months carries a materially different risk profile than a patient two weeks into their first dose increase, even on the identical drug and dose. This is why dose phase is a primary input in the tool above rather than a secondary consideration.
Who wrote this page, and what is their qualification?
This page is compiled and maintained by Anthony K C Fong, a New York-licensed attorney (not a clinician), who synthesizes and links to the primary published guidance from ASA, AGA, ASMBS, ISPCOP, and SAGES rather than offering independent clinical judgment. Every substantive recommendation traces to a cited primary source below - this page does not add clinical interpretation beyond what those societies have published. Anesthesia and surgical teams should verify against the current published guidance and their own institution's protocol before acting; this tool is a reference aid, not a substitute for institutional policy or clinical judgment.
Primary references
- ASA - New Multi-Society GLP-1 Clinical Practice Guidance (October 2024)
- Multisociety Clinical Practice Guidance - Clinical Gastroenterology and Hepatology
- ASA 2023 Original Consensus-Based Guidance (superseded but still cited)
- PubMed: Joshi GP et al. ASA Consensus-Based Guidance on Preoperative Management
Last reviewed against multi-society guidance: April 25, 2026. Recommendations may have updated since this review - always verify against the most recent published guidance and your institution's protocols before acting.
Useful? Share with your service line or anesthesia department.
See the patient-facing GLP-1 cost & weight loss calculator →