Perioperative Insulin Management for Type 1 Diabetes on Day of Surgery
For adults with type 1 diabetes undergoing surgery, transition immediately to continuous intravenous insulin infusion (IV insulin) with concurrent IV glucose (4 g/hour) and electrolytes, targeting blood glucose 90-180 mg/dL (5-10 mmol/L), with monitoring every 1-2 hours. 1
Preoperative Preparation
Schedule surgery as early as possible in the morning to minimize prolonged fasting, which is critical for preventing both hypoglycemia and ketoacidosis in type 1 diabetes 1
If the patient uses an insulin pump, it must be removed at the start of the intervention with mandatory immediate transition to IV insulin infusion 1
Never allow a type 1 diabetic patient to be without insulin replacement, as they lack endogenous insulin production and are at high risk for diabetic ketoacidosis 2
Intraoperative Insulin Protocol
Route and Formulation
Administer ultra-rapid short-acting insulin analogues via continuous IV infusion (also called IVES - intravenous insulin by electronic syringe) 1
Always co-administer IV glucose at approximately 4 g/hour along with appropriate electrolytes to prevent hypoglycemia and insulin-induced hypokalemia 1, 3
Target Blood Glucose Range
Maintain blood glucose between 90-180 mg/dL (5-10 mmol/L), with therapeutic adjustment if glucose exceeds 180 mg/dL (10 mmol/L) 1, 3
Avoid tight glycemic control (80-120 mg/dL or 4.4-6.7 mmol/L), as this increases the risk of severe hypoglycemia and potentially mortality without improving outcomes 1, 3
Moderate glycemic control (140-180 mg/dL or 7.7-10 mmol/L) represents the optimal balance, reducing morbidity/mortality without increasing hypoglycemia frequency 1, 3
Monitoring Requirements
Measure blood glucose every 1-2 hours using arterial or venous blood samples, not capillary fingerstick measurements 1, 3
Capillary glucose readings overestimate blood glucose levels, especially during vasoconstriction and hypoglycemia; a capillary reading of 70 mg/dL (3.8 mmol/L) should be considered hypoglycemia and verified by laboratory measurement 1, 3
Check serum potassium every 4 hours to detect and prevent insulin-induced hypokalemia 1, 3
Fluid Management Considerations
Use balanced crystalloid solutions (Ringer's lactate or Plasmalyte) rather than 0.9% normal saline to reduce risk of hyperchloremic metabolic acidosis and acute kidney injury 3
All standard solutes, including Ringer lactate, may be used safely in the perioperative period for diabetic patients 1, 3
Critical Pitfalls to Avoid
Never discontinue insulin in type 1 diabetes, even if the patient is NPO (nothing by mouth), as this will rapidly lead to diabetic ketoacidosis 2
Never administer IV insulin without simultaneous glucose and electrolyte provision, as this markedly increases hypoglycemia risk 1, 3
Do not rely solely on capillary glucose readings; confirm any concerning value with laboratory measurement 1, 3
Do not use sliding-scale insulin alone without basal insulin coverage, as this is ineffective and excludes the critical basal component 4, 2
Postoperative Transition Planning
Continue IV insulin infusion until the patient can eat and manage their diabetes autonomously 1
When transitioning from IV to subcutaneous insulin, calculate the subcutaneous dose as half the total 24-hour IV insulin requirement: give half as once-daily long-acting basal insulin (in the evening) and divide the other half into three equal doses of ultra-rapid analogue before each meal 1
Administer the first dose of long-acting basal insulin immediately after stopping the IV infusion, ideally at 20:00 hours, leaving the IV insulin syringe in place until subcutaneous insulin is given 1
If the patient uses an insulin pump, reconnect it only when the patient can manage autonomously; otherwise, initiate a basal-bolus subcutaneous insulin regimen 1