The standard treatment for patients with diabetic ketoacidosis (DKA) is the use of low-dosage intravenous, subcutaneous, or intramuscular insulin. Although all routes of administration have been shown to be effective, the preferred method is intravenous because of concern about delayed response to subcutaneous or intramuscular insulin. Treatment with intravenous insulin usually requires admission to the intensive care unit for close monitoring of the patient. However, the development of insulin lispro (Humalog) and aspart insulin (Novolog) provides another option for treating DKA. Both of the newer insulins have a more rapid onset of action, usually 10 to 20 minutes, and peak within 30 to 90 minutes. Umpierrez and associates compared the efficacy and safety of subcutaneous insulin lispro with low-dosage continuous intravenous regular insulin in the treatment of patients with uncomplicated DKA.

The study was a prospective, randomized, open trial of patients admitted for uncomplicated DKA. Participants were randomly assigned to receive subcutaneous insulin lispro in the general medical ward or intermediate care unit, or intravenous regular insulin in the intensive care unit. The insulin lispro regimen was 0.3 units per kg followed by 0.1 units per kg per hour until correction of hyperglycemia. The regular insulin regimen was 0.1 units per kg followed by continuous infusion of 0.1 units per kg per hour until correction of hyperglycemia. Treatment for both groups was followed with 0.05 to 0.1 units per kg per hour until resolution of DKA. The primary outcomes measured were time required to resolve hyperglycemia and ketoacidosis and the rate of hypoglycemia during insulin therapy.

Forty patients enrolled in the trial and were assigned to treatment. On admission, the two groups had similar biochemical parameters. The time to resolution of hyperglycemia and ketoacidosis, length of hospital stay, amount of insulin used until resolution of DKA, and rate of hypoglycemia were similar between the groups. Hospital expenses for patients treated in the intensive care unit were 39 percent higher than those for patients treated with insulin lispro.

The authors conclude that hourly treatment with subcutaneous insulin lispro is a safe alternative to intravenous regular insulin for adults with uncomplicated DKA. They add that treatment with subcutaneous insulin lispro is more cost-effective than intravenous regular insulin because treatment with insulin lispro can be performed in a non-intensive care setting.