What are the perioperative anesthetic guidelines for patients on Glucagon-like peptide-1 (GLP1) agonists, such as liraglutide (Victoza) and semaglutide (Ozempic), undergoing surgery?

Perioperative Anesthetic Guidelines for GLP-1 Receptor Agonists

For patients on GLP-1 receptor agonists, withhold these medications for at least three half-lives before elective surgery to reduce the risk of pulmonary aspiration due to retained gastric contents. 1

Risk Assessment

• GLP-1 receptor agonists significantly delay gastric emptying, increasing the risk of regurgitation and pulmonary aspiration during anesthesia, even with proper fasting 2
• Multiple case reports document regurgitation and aspiration during general anesthesia in patients taking GLP-1 agonists despite prolonged fasting periods 1, 2
• The risk is particularly high in patients who have recently started the medication or increased their dose 1

Recommendations Based on Indication

For Weight Management Patients:

• Withhold GLP-1 receptor agonists for at least three half-lives before elective surgery 1
• For semaglutide (Ozempic), this means approximately 3 weeks due to its long half-life 1, 2
• The risks of continuing until shortly before surgery likely outweigh the benefits for weight loss patients 2

For Type 2 Diabetes Patients:

• Consult with the treating endocrinologist regarding the risks and benefits of holding the drug 1
• Discuss recommendations for bridging diabetic therapy if the GLP-1 receptor agonist is to be held for longer than the next scheduled dosing time 1
• Consider the impact on perioperative glycemic control when making this decision 1, 3

Risk Reduction Strategies

For high-risk patients (unable to hold for three half-lives, recently started medication, or experiencing GI symptoms):

• Consider prokinetic drugs such as metoclopramide or erythromycin pre-operatively 1
• Use point-of-care gastric ultrasound to assess residual gastric contents 1
• Consider rapid sequence intubation to reduce aspiration risk 1
• In very high-risk patients, pre-emptive gastric decompression may be considered 1
• Consider postponement and rescheduling of the procedure when appropriate 1
• Implement clear fluid diet for some period before pre-operative fasting 1

Decision Algorithm for Day of Procedure

1. Has the GLP-1 receptor agonist been withheld for three half-lives?

   • If YES: Proceed if gastric volume <1.5 ml/kg and no solid matter observed 1
   • If NO: Consider the patient high-risk and implement risk reduction strategies 1

2. For high-risk patients:

   • Administer prokinetic drugs 1
   • Perform gastric ultrasonography 1
   • If significant gastric contents remain, consider delaying procedure or proceeding with rapid sequence intubation 1

Important Caveats

• Recent evidence suggests that even holding weekly GLP-1 receptor agonists like semaglutide for 1 week may be insufficient to normalize gastric emptying 2
• There is some contradictory evidence suggesting that patients on long-term GLP-1 receptor agonist therapy (>12 weeks) may develop tachyphylaxis to the gastric emptying effects 4
• A recent retrospective cohort analysis found no increased risk of perioperative complications in GLP-1 receptor agonist users compared to non-users 5, but this conflicts with case reports and current guidelines

Documentation Requirements

• Indication and dose of GLP-1 receptor agonist 1
• Date drug commenced, dose variations, last dose taken 1
• Symptoms of nausea, vomiting or abdominal distention 1
• Co-prescribed drugs that can delay gastric emptying (opioids, proton pump inhibitors, tricyclic antidepressants) 1
• Recent intake of recreational drugs which can delay gastric emptying 1
• Previous gastro-oesophageal surgery 1