Insulin Dosing for Diabetic Ketoacidosis (DKA)

Initial Insulin Therapy

The American Diabetes Association recommends an initial insulin dose of 0.1 units/kg/hour without an initial bolus dose for moderate to severe DKA 1, 2
For adult patients with DKA, the initial insulin dose is 0.1 units/kg/hour, approximately 5-7 units/hour, once hypokalemia is excluded 2, 3
The low-dose insulin regimen decreases plasma glucose concentration at a rate of 50-75 mg/dl/hour 2, 3

If plasma glucose does not fall by 50 mg/dl from the initial value in the first hour, the insulin infusion may be doubled every hour until a steady glucose decline between 50-75 mg/hour is achieved 2, 3
When serum glucose reaches 250 mg/dl, decrease the insulin infusion rate to 0.05-0.1 units/kg/hour and add dextrose to the IV fluids 2, 1
Monitor blood glucose every 1-2 hours and draw blood every 2-4 hours to determine serum electrolytes, glucose, and venous pH 1, 4

For mild DKA, subcutaneous insulin administration can be effective, starting with a "priming" dose of regular insulin of 0.4-0.6 units/kg body weight 5, 6
Patients with mild DKA can receive 0.1 units/kg/hour of regular insulin subcutaneously or intramuscularly 5, 2

Continue insulin therapy until resolution of ketoacidosis, defined as glucose <200 mg/dl, serum bicarbonate ≥18 mEq/l, venous pH >7.3, and anion gap ≤12 mEq/L 1, 6
When DKA resolves, transition to a multiple-dose subcutaneous insulin schedule using a combination of short/rapid-acting and intermediate/long-acting insulin 5, 7

Premature termination of insulin therapy can lead to recurrence of DKA 1, 6
Inadequate monitoring of potassium levels during insulin therapy can cause dangerous hypokalemia 1, 6
Relying on nitroprusside method to measure ketones is misleading as it only measures acetoacetic acid and acetone, not β-hydroxybutyrate 5, 2

Direct measurement of β-hydroxybutyrate in blood is the preferred method for monitoring DKA resolution 5, 6
Ketonemia typically takes longer to clear than hyperglycemia, so insulin therapy should continue until ketoacidosis resolves regardless of glucose levels 1, 6
Bicarbonate administration is generally not recommended for DKA patients with pH >6.9 4, 6