Insulin Dosing for Diabetic Ketoacidosis (DKA)
Initial Insulin Administration
- The American College of Physicians recommends a continuous intravenous regular insulin infusion at an initial rate of 0.1 units/kg/hour without an initial bolus dose for adult patients with DKA 1, 2
- Continuous intravenous regular insulin infusion is the standard of care for critically ill and mentally obtunded patients with DKA 1
- Insulin therapy should be continued until resolution of ketoacidosis (pH >7.3, serum bicarbonate ≥18 mEq/L, and anion gap ≤12 mEq/L) regardless of glucose levels 1
Monitoring and Titration
- The American Academy of Pediatrics recommends monitoring blood glucose hourly or more closely as needed, with the goal of gradually reducing blood glucose by 50-100 mg/dL per hour 3
- When serum glucose reaches 250 mg/dL, change IV fluids to include dextrose (D5W with 0.45-0.75% NaCl) while continuing insulin therapy to resolve ketosis 1
- Draw blood every 2-4 hours to determine serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2
Special Populations
- For pediatric patients, the recommended IV insulin infusion rate is lower: 0.05-0.10 unit/kg per hour 3, 5
- For mild or moderate uncomplicated DKA in stable patients, subcutaneous rapid-acting insulin analogs (0.25-0.50 unit/kg per dose) combined with aggressive fluid management can be as effective as intravenous insulin 3, 1
Transition to Subcutaneous Insulin
- When DKA resolves (glucose <200 mg/dL, serum bicarbonate ≥18 mEq/L, venous pH >7.3, and anion gap ≤12 mEq/L) and the patient can eat, transition to subcutaneous insulin 1, 4
- Administer basal insulin 2-4 hours before stopping the intravenous insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2
Common Pitfalls to Avoid
- Premature termination of insulin therapy before complete resolution of ketosis can lead to recurrence of DKA 4
- Inadequate monitoring of potassium levels during insulin therapy, which can cause hypokalemia 1, 4