Can a patient with diabetes resume insulin therapy after an operation?

Resuming Insulin After Surgery

Yes, patients with diabetes should resume insulin therapy after surgery, with the specific approach depending on diabetes type: Type 1 diabetes patients must never have basal insulin stopped due to ketoacidosis risk, Type 2 diabetes patients on insulin should resume at half-dose pending endocrinology consultation, and gestational diabetes patients should discontinue insulin with close monitoring. 1

Type 1 Diabetes: Critical - Never Stop Basal Insulin

Basal insulin must be resumed immediately when intravenous insulin is discontinued to prevent life-threatening ketoacidosis. 1

• Resume the basal-bolus insulin regimen with dose reduction to either 80% of pre-pregnancy doses or 50% of end-of-pregnancy doses (if postpartum). 1
• If the last basal insulin injection was >24 hours ago, administer it immediately upon stopping the insulin infusion. 1
• For insulin pump users, restart the pump as soon as the intravenous insulin is discontinued. 1
• Type 1 diabetes patients are typically autonomous in managing their diabetes and should be involved in resumption decisions. 1

Type 2 Diabetes on Insulin: Resume at Reduced Dose

Continue insulin at half the pre-operative dose while awaiting diabetologist consultation. 1

• This conservative approach prevents both hyperglycemia and hypoglycemia during the immediate postoperative period when oral intake may be variable. 1
• Insulin remains the mainstay of perioperative glucose management and should not be delayed. 2
• There is little role for oral antidiabetic medications in the early postoperative phase. 2

Gestational Diabetes: Discontinue Insulin

Stop insulin therapy immediately postpartum for gestational diabetes patients. 1

• Monitor blood glucose before meals and 2 hours postprandially for 48 hours. 1
• Consult diabetology if fasting glucose >1.26 g/L (7 mmol/L) or postprandial glucose >2 g/L (11 mmol/L). 1

General Postoperative Insulin Management Principles

Glycemic Targets

• Target blood glucose range: 6-8.8 mmol/L (1.10-1.60 g/L) after vaginal delivery. 1
• Slightly lower targets after cesarean section to support wound healing. 1
• Good postoperative glucose control reduces risk of in-hospital death and shortens length of stay. 2

Timing of Resumption

• Resume subcutaneous insulin when the patient is clinically stable, tolerating oral intake, and has adequate renal function (typically within 48 hours). 3
• For patients on high-dose home insulin (≥0.6 units/kg/day), reduce total daily dose by 20% upon resumption to prevent hypoglycemia. 4
• Insulin should be provided during the perioperative period to suppress excessive lipolysis and ketogenesis. 5

Monitoring Requirements

• Daily fasting blood glucose monitoring is essential during the titration phase. 4
• Target fasting plasma glucose: 80-130 mg/dL (4.4-7.2 mmol/L). 4
• Bedside glucose monitoring should guide insulin dose modifications. 6

Common Pitfalls to Avoid

• Never discontinue basal insulin in Type 1 diabetes patients - this creates immediate ketoacidosis risk. 1
• Do not rely solely on sliding scale insulin postoperatively - use scheduled basal-bolus regimens. 7, 8
• Avoid therapeutic inertia: 70% of hyperglycemic postoperative patients remain on inadequate short-acting insulin only rather than appropriate basal-bolus therapy. 8
• Do not delay insulin resumption in patients with poor glycemic control - each delay increases complication risk. 7
• Insulin requirements may be increased by infection, hepatic disease, obesity, steroid treatment, and cardiovascular surgery. 6

Special Considerations

• Continue metformin when resuming insulin unless contraindicated (creatinine clearance <60 mL/min). 3, 7
• For patients requiring dose adjustments, increase by 2-4 units every 3 days until fasting glucose reaches target. 4
• If hypoglycemia occurs, reduce dose by 10-20% immediately. 4
• Intravenous insulin may be limited to ICU settings due to need for frequent monitoring. 9