Medications and Surgery: Oral Hypoglycaemics, SGLT2 Inhibitors, Insulin, DOACs

Pre- and Post-Operative Advice

1. Oral Hypoglycaemics

• Pre-Op:

  • Stop on the morning of surgery to avoid hypoglycaemia during fasting.

• Post-Op:

  • Restart once the patient is eating meals regularly and has stable blood glucose levels.

2. SGLT2 Inhibitors (e.g. dapagliflozin, empagliflozin)

• Pre-Op:

  • Cease 3 days prior to surgery (reduces risk of euglycaemic ketoacidosis, especially under fasting/anaesthetic conditions).

• Post-Op:

  • Restart once patient is eating and drinking normally and no signs of ketoacidosis.

3. Insulin

• Long-Acting Insulin:

  • Continue at usual dose throughout the perioperative period.

• Short-Acting/Mealtime Insulin:

  • Morning Surgery: Withhold the morning dose.

  • Afternoon Surgery: Take half of the usual morning dose if a small breakfast is consumed.

4. DOACs (Direct Oral Anticoagulants)

• Pre-Op:

  • Generally stop 48 hours prior for most procedures.

  • If low bleeding risk + normal eGFR: stop 24 hours prior.

• Post-Op:

  • Resume 48 hours after surgery in standard or high-risk procedures.

  • If low bleeding risk procedure: resume 24 hours post-op, regardless of eGFR.

Monitoring

• Oral Hypoglycaemics: Check blood glucose post-operatively to prevent hyperglycaemia if reintroduction is delayed.

• SGLT2 Inhibitors: Remain vigilant for euglycaemic DKA (look for abdominal pain, nausea, normal glucose but ketones).

• Insulin: Monitor intra- and post-op glucose to avoid hypo- or hyperglycaemia. Adjust IV insulin or glucose infusion as needed if prolonged fasting.

• DOACs: Observe for any excess bleeding during or after surgery, especially in high-risk operations.

Complications

1. Oral Hypoglycaemics

   • Hypoglycaemia if taken during prolonged fasting.

   • Prolonged hyperglycaemia if not resumed promptly post-op.

2. SGLT2 Inhibitors

   • Euglycaemic ketoacidosis with fasting or post-op dehydration.

   • Increased risk if fluid intake is poor or patient remains NPO (nil by mouth) for extended periods.

3. Insulin

   • Hypoglycaemia from delayed eating or incorrect dosing in fasting states.

   • Hyperglycaemia if insulin doses are missed for too long.

4. DOACs

   • Excessive bleeding if not stopped early enough before high-bleeding-risk procedures.

   • Thromboembolism if the drug is restarted too late post-operatively.

Additional Considerations

• Renal Function: Check eGFR pre-operatively to decide DOAC timing; SGLT2 inhibitor cessation may require longer if renal function is borderline.

• Bleeding Risk: Collaborate with the surgical team to tailor medication timing based on the procedure’s bleeding risk.

• Individual Variability: Adjust instructions for each patient’s comorbidities (heart failure, CKD, etc.).

• Written Plan: Provide clear written instructions to patients to avoid confusion around medication withholding and resumption post-operatively.