Overview
Mike presented updated recommendations from the AGBI on perioperative management of GLP-1 receptor antagonists and touched on SGLT2 inhibitor guidance, emphasizing individualized risk assessments and pragmatic mitigation strategies due to limited high-quality evidence.
Background and Guideline Development
- The AGBI guidelines were published in January as a multi-disciplinary consensus statement including input from surgeons, anesthetists, doctors, and pharmacists.
- Recommendations were finalized through a three-stage modified Delphi process, requiring over 75% agreement for inclusion.
- The guideline addresses increasing clinical relevance due to higher patient use of these medications.
Physiology and Mechanism of GLP-1 and Related Drugs
- GLP-1 and GIP are incretin hormones secreted in response to glucose, enhancing insulin secretion and sensitivity.
- GLP-1 receptor antagonists and DPP4 inhibitors are used to manage diabetes and obesity, with additional cardioprotective benefits.
- These drugs reduce appetite, slow gastric emptying, increase peripheral glucose uptake, and improve cardiovascular markers.
Indications and Use Cases
- Used in type 2 diabetes after failure of three oral agents or when insulin is unsuitable, usually with BMI >35.
- Also indicated for weight management in patients with BMI >35 and co-morbidities, with stricter criteria for primary care prescribing.
- Newer agents like Tirzepatide (Mounjaro) show significant weight loss and potential cardiovascular benefits.
Perioperative Benefits and Risks
- Continuing GLP-1 agonists perioperatively may improve glycemic and cardiovascular outcomes, reduce post-op insulin needs, and lower hypoglycemia risk.
- Main concern is delayed gastric emptying and pulmonary aspiration, though the actual risk magnitude is unclear due to limited evidence.
- Tachyphylaxis reduces the risk of delayed gastric emptying in long-term users, but recent starts/increased doses pose higher risk.
Previous vs. Updated Recommendations
- Prior ASA guidance recommended withholding GLP-1 agonists on day of surgery (daily dose) or 1 week prior (weekly dose), without nuance for indication, dose, or procedural factors.
- New guidance opposes blanket recommendations and emphasizes individualized aspiration risk assessment, considering drug, patient, and procedural factors.
Perioperative Management Strategies (GLP-1 Receptor Antagonists)
- Continue GLP-1 agonists perioperatively, using individualized risk assessment and shared decision-making.
- Mitigation strategies: adhere to fasting guidance, consider regional anesthesia, perform RSI/intubation, use head-up positioning, NG tube placement, or prokinetics as appropriate.
- Gastric ultrasound is suggested as a risk assessment tool but its utility in obesity and inexpert hands is uncertain.
Perioperative Management: SGLT2 Inhibitors
- SGLT2 inhibitors can precipitate euglycemic DKA due to increased ketone production, especially under perioperative stress.
- Indications: diabetes, heart failure, CKD; risk of DKA exists in both diabetic and non-diabetic users.
- Drug half-life is ~12 hours, but glycosuric effects persist longer; cases of DKA reported even with >72 hours cessation.
- Recommendation: withhold SGLT2 inhibitors the day before surgery, aim to minimize fasting, consider glucose fluids during prolonged fasting, and monitor glucose/ketones per institutional protocol.
Decisions
- Continue GLP-1 receptor antagonists perioperatively with individualized risk assessment and mitigation strategies.
- Withhold SGLT2 inhibitors the day before surgery and employ additional risk mitigation measures.
Recommendations / Advice
- Apply individualized perioperative risk assessment for all patients on GLP-1 or SGLT2 agents.
- Use shared decision-making and practical risk mitigation strategies tailored to patient, drug, and surgical factors.
- Maintain vigilant glucose and ketone monitoring perioperatively, adapting frequency to institutional capabilities.