With the increasing use of Glucagon-Like Peptide-1 Receptor (GLP-1R) agonists for diabetes management and weight loss, their implications in perioperative care have gained attention. These medications affect gastric emptying and glucose metabolism, which may pose risks during anaesthesia. A recent article by Paggers et al. (2025) explores current evidence, challenges, and future perspectives in managing surgical patients on GLP-1R agonists.

Key takeaways

• 1 in 20 patients undergoing surgery is on GLP-1R agonists.
• These drugs slow gastric emptying, raising concerns about pulmonary aspiration during anaesthesia.
• No direct causal link has been established between GLP-1R use and increased aspiration risk.
• The American Society of Anesthesiologists (ASA) recommends withholding these drugs before surgery, but definitive guidelines remain unclear.
• Ultrasound assessments could improve risk stratification for perioperative management.

Understanding GLP-1R agonists

Mechanism of action

GLP-1R agonists mimic the hormone GLP-1, which regulates:

• Insulin secretion (increases insulin release in response to glucose).
• Glucagon suppression (reduces glucose production in the liver).
• Gastric emptying (slows digestion to reduce postprandial glucose spikes).
• Satiety regulation (reduces appetite, aiding in weight loss).

Clinical uses

• Type 2 Diabetes Mellitus (T2DM): Effective in lowering blood glucose without a significant risk of hypoglycemia.
• Obesity management: Used widely for weight loss, even in non-diabetic individuals.
• Cardiovascular benefits: May reduce the risk of major adverse cardiovascular events (MACE).
• Neurological and anti-inflammatory effects: Shows promise in Alzheimer’s disease and neuroprotection.

GLP-1R agonists and perioperative outcomes

1. Gastroparesis and pulmonary aspiration risk

• GLP-1R agonists delay gastric emptying, leading to concerns about residual gastric content at the time of anaesthesia.
• Some studies report solid food remnants in the stomach even after prolonged fasting.
• However, no direct link has been found between GLP-1R agonists and higher pulmonary aspiration risk.

2. Impact on perioperative glycaemia

• Less hypoglycaemia risk than insulin and better perioperative glucose control.
• Stopping GLP-1R agonists preoperatively may lead to worsened glycaemia and metabolic instability.

3. Drug interactions and metabolism

• Weight loss associated with GLP-1R use may alter drug metabolism of weight-based medications (e.g., levothyroxine, warfarin).
• No significant changes in oral drug absorption, but caution is advised in patients with renal dysfunction.

Clinical guidelines and recommendations

1. Preoperative discontinuation

• ASA Guidelines (2023): Consider stopping daily doses on the day of surgery and weekly doses one week before surgery.
• Australian and New Zealand College of Anaesthetists (ANZCA): Recommends rapid sequence induction for all GLP-1R users.

2. Use of ultrasound for gastric assessment

• Point-of-care ultrasound (PoCUS) helps determine gastric contents preoperatively.
• If solids are detected → High aspiration risk → Surgery may need to be delayed.

3. Postoperative considerations

• Restarting GLP-1R agonists requires gradual titration to avoid severe gastrointestinal symptoms.
• Patients may experience dehydration and malnutrition due to prolonged nausea and reduced appetite.

Conclusion

GLP-1R agonists have revolutionized diabetes and obesity management, but their role in perioperative care remains complex. While gastroparesis raises concerns, no confirmed increased aspiration risk has been established. Ultrasound-based assessments and individualized patient management will likely shape future guidelines.

Reference: Paggers L, Mesotten D, Stragier H. Glucagon-like peptide-1 receptor agonists in peri-operative care: Dispelling myths and unveiling insights with essential considerations for anaesthesiologists. Eur J Anaesthesiol. 2025;42(2):140-151.

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