What are the guidelines for general anesthesia in patients taking Glucagon-like peptide-1 (GLP1) receptor agonists, such as semaglutide (Ozempic) or liraglutide (Victoza), with a history of diabetes mellitus and potential impaired renal or liver function?

Guidelines for General Anaesthesia in Patients Taking GLP-1 Medications

Patients taking GLP-1 receptor agonists should continue these medications before elective surgery, undergo full risk assessment, and receive peri-operative techniques that mitigate pulmonary aspiration risk during sedation or general anaesthesia. 1

Medication Management by Drug Type

Weekly GLP-1 Receptor Agonists (Semaglutide, Dulaglutide, Tirzepatide)

The most recent 2025 multidisciplinary consensus from the Association of Anaesthetists and multiple UK societies recommends continuing GLP-1 receptor agonists before surgery rather than stopping them. 1 This represents a significant departure from earlier recommendations.

However, emerging evidence suggests nuanced risk stratification is critical:

• For non-diabetic patients using GLP-1 RAs for weight loss: Hold semaglutide for at least 3 weeks (three half-lives) before elective surgery, as the risks of continuing until shortly before surgery outweigh the benefits 2
• For diabetic patients: Consult with endocrinology to weigh glycemic control benefits against aspiration risk, as prolonged cessation may have detrimental effects on perioperative glycemic control 2
• Critical caveat: Discontinuation for only 7 days (one week) is insufficient—studies demonstrate this shorter period did not decrease the prevalence of retained gastric contents 2

Daily GLP-1 Receptor Agonists (Liraglutide)

• Hold for 3-4 days (approximately three half-lives) before elective procedures 2

SGLT2 Inhibitors

Patients taking SGLT2 inhibitors should omit them the day before and the day of a procedure to mitigate euglycaemic ketoacidosis risk. 1

Risk Assessment and Stratification

High-Risk Indicators Requiring Enhanced Precautions

Document the following in preoperative assessment 2:

• Medication details: Indication, dose, date commenced, dose variations, last dose taken
• Gastrointestinal symptoms: Nausea, vomiting, abdominal distention
• Co-prescribed medications that delay gastric emptying: opioids, proton pump inhibitors, tricyclic antidepressants
• Recent recreational drug use: alcohol, cannabis (both delay gastric emptying)
• Duration since starting or dose escalation: Patients who recently started or increased dose require extra caution 2

Evidence of Aspiration Risk

• 24.2% of patients on semaglutide had residual gastric content compared to 5.1% of controls, even with 12+ hour fasting periods and 10-14 days of medication discontinuation 2
• Multiple case reports document pulmonary aspiration requiring ICU admission in patients who fasted 18-20 hours and stopped semaglutide 4-6 days before surgery 2
• Patients with pre-existing digestive symptoms show significantly higher rates of gastric retention and require more than 21 days discontinuation 2

Risk Mitigation Strategies When Adequate Holding Period Not Achieved

Preoperative Interventions

1. Consider postponement and rescheduling of the procedure to allow adequate medication clearance 2
2. Point-of-care gastric ultrasound pre-operatively to assess for residual gastric contents (target gastric volume <1.5 ml/kg) 2
3. Administer prokinetic drugs such as metoclopramide or erythromycin pre-operatively to enhance gastric emptying 2

Intraoperative Techniques

1. Implement rapid-sequence intubation with full airway protection 2
2. Choose endotracheal intubation over supraglottic airways, as case reports show aspiration with supraglottic devices 2
3. Treat as "full stomach" case with appropriate precautions 2
4. Consider pre-emptive gastric decompression in very high-risk patients 2

Shared Decision-Making Approach

All patients should have risks and mitigation strategies discussed with a shared decision-making approach. 1 This includes:

• Openly discussing the risks and benefits of proceeding with surgery if medication has not been held for adequate duration 2
• Explaining that standard fasting guidelines are insufficient for patients on GLP-1 RAs—retained gastric contents persist despite extended fasting 2
• Documenting the discussion and patient's understanding of aspiration risk 2

Special Considerations for Renal and Hepatic Impairment

• No dose adjustment required for semaglutide, liraglutide, or dulaglutide across all stages of chronic kidney disease, including end-stage renal disease 3
• GLP-1 receptor agonists reduce albuminuria and slow eGFR decline, making them preferred agents in patients with renal impairment 3
• Patients with liver impairment can safely receive GLP-1 RAs, as these medications may improve metabolic dysfunction-associated steatotic liver disease 3

Critical Pitfalls to Avoid

1. Do not assume standard fasting times are adequate—retained gastric contents can occur despite 8-12 hour fasting periods in patients on GLP-1 RAs 4
2. Do not rely on short discontinuation periods—one week is insufficient for long-acting agents 2
3. Avoid using supraglottic airway devices in patients who have not had adequate medication discontinuation 2
4. Do not ignore the distinction between diabetes and weight loss indications—management differs based on the clinical context 2

Contraindications and Bowel Obstruction

GLP-1 receptor agonists are contraindicated in patients with active bowel obstruction and should be discontinued immediately if bowel obstruction is suspected or diagnosed. 4 The medications significantly delay gastric emptying and can worsen or precipitate bowel obstruction, particularly in patients with pre-existing gastrointestinal motility disorders. 4