24-year-old woman with type 1 diabetes mellitus and poor compliance is admitted to the ICU

restore circulating volume with boluses of normal saline

In a patient with diabetic ketoacidosis, the initial therapeutic intervention should be the restoration of circulating volume using normal saline. After determining the level of dehydration, intravenous fluid replacement should be started. In most persons, saline 0.9% is started at 15 to 20 mL/kg/hour. Fluid status, cardiac status, urine output, blood pressure, and electrolyte levels should be monitored. Once the corrected sodium concentration is normal or high (> 135 mEq/L), the solution can be changed to saline 0.45%. Dextrose is added when the glucose level decreases to 200 mg/dL.

To further correct hyperglycemia, insulin should be added to intravenous fluids 1 to 2 hours after fluids are initiated. An initial bolus of 0.1 units/kg should be given with an infusion of 0.1 units/kg/hour. Glucose level should decrease by about 50 to 70 mg/dL/hour, and the insulin infusion should be adjusted to achieve this goal.

Once the glucose level decreases to 200 mg/dL, the insulin infusion rate should be decreased to 0.05 to 0.1 units/kg/hour, and dextrose should be added to the intravenous fluids to maintain a glucose level between 150 and 200 mg/dL.

Subcutaneous insulin is not an appropriate initial treatment for DKA. A sliding scale of insulin would be appropriate following stabilization of the patient. Intravenous insulin bolus of regular insulin 0.15units/kg is not an appropriate initial treatment for DKA, given the need for restoration of circulating volume.

References:

Crandall J, Shamoon H. Diabetes mellitus. In: Goldman L, Schafer AI. Goldman-Cecil Medicine. 25th ed., 2016: 1527-1548.

Westerburg D. Diabetic ketoacidosis: evaluation and treatment. Am Fam Physician. 2013;87(5):337-346.