Surgery requires careful diabetes management. Hold SGLT2 inhibitors 3–4 days before; hold metformin and GLP-1 agents the day of surgery; reduce basal insulin 20–30% the night before; never take mealtime insulin if fasting. Target blood glucose of 140–180 mg/dL perioperatively. Always inform your entire surgical team about your diabetes and all medications.
Surgery presents unique challenges for people with diabetes — the stress of an operation raises blood sugar, fasting changes your medication needs, and some diabetes medications carry specific surgical risks. Preparation and communication with your entire care team are essential.
Why Surgery Is Different for People with Diabetes
Physical and emotional stress triggers cortisol and adrenaline release, which raises blood sugar. Fasting before surgery eliminates food intake but not the hormonal glucose response. Simultaneously, many diabetes medications need adjustment to prevent dangerous complications. Poor glucose control increases:
- Surgical site infection risk (2–3x higher with hyperglycemia)
- Poor wound healing
- Hospital length of stay
- Cardiovascular events during surgery
Which Medications to Hold
⚠️ Critical: Always provide a complete medication list to your surgeon, anesthesiologist, and pre-op nurse. Do not assume your primary care doctor has communicated your diabetes medications to the surgical team.
| Medication | Action | Why |
|---|---|---|
| SGLT2 inhibitors (Jardiance, Farxiga, Invokana) | Hold 3–4 days before surgery | Euglycemic DKA risk — even with normal blood sugar |
| Metformin | Hold day of surgery; hold 48 hrs after if IV contrast used | Lactic acidosis risk with dehydration/contrast |
| GLP-1 agonists (Ozempic, Mounjaro weekly) | Hold 1 week before surgery | Delayed gastric emptying → aspiration risk under anesthesia |
| Sulfonylureas (glipizide, glimepiride) | Hold morning of surgery | Hypoglycemia while NPO |
| DPP-4 inhibitors (Januvia, Tradjenta) | Usually hold day of surgery | Low hypoglycemia risk but typically held while NPO |
| Insulin (mealtime/bolus) | Do NOT take if NPO | Hypoglycemia without food |
| Basal insulin | Reduce 20–30% night before; continue reduced dose | Still needed to prevent hyperglycemia — but adjusted for fasting |
Blood Sugar Targets Perioperatively
- Target range: 140–180 mg/dL before, during, and after surgery
- Below 140 is acceptable and preferred if achievable without hypoglycemia
- Above 180 increases infection and healing risk
- Below 70 (hypoglycemia) is dangerous and must be prevented
Monitoring
- Check blood sugar the morning of surgery
- Bring your glucose meter and glucose tablets to the hospital
- CGM sensors may need to be removed depending on surgical site and cautery use — ask your anesthesiologist
- After surgery, resume medications only when eating regularly and kidney function is confirmed (for metformin)
What to Tell Your Surgical Team
- That you have diabetes (Type 1 or Type 2)
- All diabetes medications by name — including OTC supplements
- Your typical blood sugar range and HbA1c
- Whether you wear a CGM or insulin pump
- Your endocrinologist's contact information
Key Takeaways
- Hold SGLT2 inhibitors 3–4 days before surgery — euglycemic DKA risk even with normal blood sugar
- Hold GLP-1 weekly injections 1 week before surgery — delayed gastric emptying/aspiration risk
- Hold metformin day of surgery; 48 hours after if IV contrast was used
- Never take mealtime insulin if fasting (NPO) for surgery
- Reduce basal insulin 20–30% the night before surgery — don't stop entirely
- Target blood glucose 140–180 mg/dL perioperatively
- Always give your complete medication list to every member of your surgical team
Our Team Can Help
All five of our providers diagnose and manage endocrine conditions.
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