Insulin Management During Perioperative Glucocorticoid Therapy
Current Lantus Dose Recommendation
For today, maintain Lantus at 8 units and hold all prandial insulin (12 units with meals) given the patient's poor oral intake. 1
The key issue here is that dexamethasone 4 mg twice daily causes significant daytime hyperglycemia with peak effects 4-6 hours after administration, but glucocorticoid effects diminish overnight. 1 With minimal food intake, the current prandial insulin dose of 12 units per meal poses substantial hypoglycemia risk and should be eliminated entirely until oral intake improves. 1
Rationale for Basal Insulin Continuation
- Basal insulin must be continued even with poor oral intake to prevent diabetic ketoacidosis, particularly in the perioperative setting. 1
- The current Lantus dose of 8 units (approximately 0.12 units/kg for this 68 kg patient) is conservative and appropriate for maintaining baseline glycemic control without excessive hypoglycemia risk. 2
- Perioperative guidelines recommend giving 60-80% of long-acting analog doses on the day of surgery, but since surgery has already occurred and the patient is in recovery, maintaining the established dose is reasonable. 1
Prandial Insulin Management
Eliminate all scheduled prandial insulin today given poor oral intake. 1
- Prandial insulin should only be administered if the patient actually consumes carbohydrates. 1
- For patients with insufficient caloric intake, guidelines explicitly state to give half the planned prandial dose or eliminate it entirely. 1
- Use correctional (sliding scale) rapid-acting insulin only if blood glucose exceeds 180 mg/dL, with doses of 2-4 units for glucose 180-250 mg/dL. 1
Carbohydrate Ratio Guidance
No fixed carbohydrate ratio should be applied today—use a "carbs consumed" approach instead. 1
When oral intake resumes:
- Start with 1 unit of rapid-acting insulin per 10-15 grams of carbohydrate actually consumed. 1
- Administer insulin after the meal rather than before to match actual intake. 1
- For enteral bolus feedings, use approximately 1 unit per 10-15 grams carbohydrate. 1
Dexamethasone Taper Considerations for Tomorrow
When dexamethasone decreases to 4 mg once daily tomorrow, expect continued daytime hyperglycemia but improved overnight control. 1
- Long-acting glucocorticoids like dexamethasone have prolonged pharmacologic effects requiring both basal and potentially NPH insulin for daytime coverage. 1
- Consider adding NPH insulin 4-6 units in the morning if daytime glucose consistently exceeds 200 mg/dL despite basal insulin. 1
- As glucocorticoid dose decreases, insulin requirements will drop—monitor closely for hypoglycemia. 1
Monitoring Protocol
Check blood glucose every 4-6 hours while oral intake remains poor. 1
- Pre-meal and bedtime glucose monitoring is essential. 1
- If glucose exceeds 300 mg/dL (16.5 mmol/L), check for ketones immediately. 1
- Target glucose range in the perioperative period should be 80-180 mg/dL. 1
Critical Pitfalls to Avoid
- Never give scheduled prandial insulin when a patient is not eating—this is the most common cause of severe hypoglycemia in hospitalized patients. 1
- Do not restart Jardiance until the patient is hemodynamically stable, eating normally, and at least 3-5 days post-surgery to avoid euglycemic diabetic ketoacidosis risk. 3, 4
- Avoid aggressive insulin dosing during glucocorticoid taper—requirements can drop precipitously, increasing hypoglycemia risk. 1
- Do not use the patient's pre-admission carbohydrate ratio (which assumed normal eating) in the setting of poor oral intake. 1
Jardiance Considerations
Keep Jardiance on hold until oral intake normalizes and surgical recovery is complete. 3