What is the recommended insulin regimen for a patient with a total daily dose (TDD) estimated from 12 units/hour in the final 6 hours?

Transitioning from IV to Subcutaneous Insulin After 12 Units/Hour in Final 6 Hours

For a patient receiving 12 units/hour in the final 6 hours of IV insulin infusion, calculate the total daily dose (TDD) as 48 units (12 units/hour × 4 = 48 units from the average hourly rate over the preceding 12 hours, not just the final 6 hours), then administer 50% of this as subcutaneous insulin (24 units), divided equally between basal and prandial components. 1

Calculating the Total Daily Dose

The guideline-recommended approach uses the average insulin infusion rate over the preceding 12 hours before transition, not just the final 6 hours mentioned in your question. 1

• If the patient received 12 units/hour consistently over 12 hours, the estimated TDD = 12 units/hour × 4 = 48 units per 24 hours 1
• This calculation assumes the hourly rate represents stable insulin requirements 1

Subcutaneous Insulin Dosing Strategy

Basal-Bolus Regimen (Preferred Approach):

• Total subcutaneous insulin: Use 50% of the calculated TDD = 24 units daily 1
• Basal insulin component: 50% of subcutaneous dose = 12 units once daily (glargine/degludec) or 6 units twice daily (NPH/detemir) 1
• Prandial insulin component: 50% of subcutaneous dose = 12 units total, divided as 4 units before each of three meals 1
• Correctional insulin: Add rapid-acting insulin for blood glucose >180 mg/dL 1

Critical Timing Considerations

Ensure transition readiness before discontinuing IV insulin: 1

• Stable glucose measurements for at least 4-6 hours consecutively 1
• Hemodynamic stability (not requiring vasopressors) 1
• Normal anion gap and resolution of acidosis if DKA was present 1
• Stable nutrition plan established 1

Timing of first subcutaneous dose:

• Administer basal insulin (glargine/degludec) 1-2 hours before stopping IV insulin 1
• For NPH/detemir, give 2 hours before stopping IV insulin 1

Evidence-Based Transition Percentage

Recent research suggests that 50-59% of the 24-hour IV insulin requirements achieves optimal glycemic control during transition, with 68% of blood glucose concentrations reaching target range (70-150 mg/dL). 2 This aligns closely with the guideline recommendation of using the average infusion rate over 12 hours (which effectively provides approximately 50% of a theoretical 24-hour requirement). 1

• The commonly used approach of 0-49% resulted in only 46% goal achievement 2
• Doses of 50-70% appear safe and effective for critically ill adults 2

Common Pitfalls to Avoid

Do not use sliding scale insulin alone in patients with established diabetes, as this approach is associated with clinically significant hyperglycemia and has been condemned in clinical guidelines. 1

Do not calculate TDD from only 6 hours of data - guidelines specifically recommend using the 12-hour average to account for diurnal variation in insulin requirements. 1

Adjust for high-risk populations: 1

• Elderly patients (>65 years): Reduce initial dose to 0.15 units/kg/day 1
• Renal failure: Use lower starting doses 1
• Poor oral intake: Consider basal-only approach with correctional insulin 1

Monitoring After Transition

• Check blood glucose before meals and at bedtime for the first 24-48 hours 1
• Target range: 140-180 mg/dL for most hospitalized patients 1
• Adjust doses by 10-20% if hypoglycemia occurs 3
• Increase by 2-4 units every 3 days if fasting glucose remains >180 mg/dL 3