How to manage blood glucose levels in a diabetic patient on Metformin (1 g/day), Glimepiride (2 mg/day), and Dapagliflozin (10 mg/day) undergoing deviated nasal septum surgery under general anesthesia?

Perioperative Glucose Management for Diabetic Patient Undergoing Nasal Septum Surgery

This patient should be transitioned to basal-bolus insulin therapy starting the evening of admission, with all oral hypoglycemic agents discontinued according to specific timelines, and blood glucose monitored every 2-4 hours throughout the perioperative period with target range 100-180 mg/dL. 1

Immediate Actions Upon Admission (2 PM, Day Before Surgery)

Discontinue Oral Hypoglycemic Agents

• Stop Dapagliflozin immediately - SGLT2 inhibitors must be discontinued 3-4 days before surgery to prevent euglycemic diabetic ketoacidosis, but since surgery is tomorrow morning, discontinue now and document the delayed cessation 1, 2

• Hold Glimepiride - all sulfonylureas should be withheld starting the evening before surgery to prevent hypoglycemia during fasting 1

• Continue Metformin today only - hold on the morning of surgery (day of procedure) 1, 3

Initiate Insulin Therapy

• Calculate total daily insulin dose (TDD): Start with 0.3-0.5 units/kg body weight for this patient on oral agents 1

• Divide as basal-bolus regimen:

  • 50% as basal insulin (long-acting analog like glargine or detemir) given once daily 1
  • 50% divided as prandial insulin (rapid-acting analog) before meals 1

• Start this evening with dinner dose of rapid-acting insulin and bedtime basal insulin 1

Day of Surgery Management (Morning, 10 AM Surgery)

Morning Insulin Dosing

• Give 75-80% of the calculated basal insulin dose on the morning of surgery 1, 3

• Hold prandial insulin since patient will be NPO 1

• Withhold Metformin on the morning of surgery 1, 3

Intraoperative Monitoring

• Check blood glucose every 2-4 hours while patient is NPO and during surgery 1, 3

• Target glucose range: 100-180 mg/dL throughout the perioperative period 1, 3

• Administer rapid-acting insulin subcutaneously for glucose >180 mg/dL using correction scale:

  • 150-200 mg/dL: 2-4 units
  • 200-250 mg/dL: 4-6 units

  • 250 mg/dL: 6-8 units and reassess 1

• Do NOT use insulin infusion - this is minor surgery under general anesthesia; subcutaneous basal-bolus is superior to sliding scale alone and adequate for this procedure 1

Postoperative Management

Immediate Post-Op (Recovery Room)

• Check blood glucose immediately after surgery and every 2-4 hours until eating 1

• Continue correction insulin as needed for glucose >180 mg/dL 1

• Resume oral intake as soon as tolerated - this is nasal surgery with minimal GI impact 1

Once Eating Resumes

• Resume basal-bolus insulin regimen with prandial doses before meals 1

• Continue monitoring blood glucose before meals and at bedtime 1

• Do NOT restart oral agents until patient is eating normally and glucose control is stable 1

Critical Pitfalls to Avoid

• Never use correction-dose insulin alone without basal insulin - this reactive approach is associated with worse outcomes and higher complication rates compared to basal-bolus regimen 1

• Do not continue SGLT2 inhibitor - the 3-4 day discontinuation window was missed, but continuing dapagliflozin increases risk of perioperative ketoacidosis even with normal glucose levels 1, 2

• Avoid hypoglycemia - reducing basal insulin to 75-80% of usual dose on surgery morning specifically prevents this complication 1

• Do not target glucose <100 mg/dL - stricter targets do not improve outcomes and increase hypoglycemia risk 1

Discharge Planning

• Transition back to oral agents can occur 24-48 hours post-discharge once eating normally and glucose stable 1

• Schedule follow-up within 1-2 weeks to reassess glycemic control and adjust medications 1

• Provide written instructions for resuming home medications and glucose monitoring 1