Is a Priming Dose of Insulin Necessary in a Low-Dose Insulin Protocol for the Treatment of Diabetic Ketoacidosis?

OBJECTIVE—The purpose of this study was to assess the efficacy of an insulin priming dose with a continuous insulin infusion versus two continuous infusions without a priming dose. RESEARCH DESIGN AND METHODS—This prospective randomized protocol used three insulin therapy methods: 1) load group using a priming dose of 0.07 units of regular insulin per kg body weight followed by a dose of 0.07 unit · kg(−1) · h(−1) i.v. in 12 patients with diabetic ketoacidosis (DKA); 2) no load group using an infusion of regular insulin of 0.07 unit · kg body weight(−1) · h(−1) without a loading dose in 12 patients with DKA, and 3) twice no load group using an infusion of regular insulin of 0.14 · kg(−1) · h(−1) without a loading dose in 13 patients with DKA. Outcome was based on the effects of insulin therapy on biochemical and hormonal changes during treatment and recovery of DKA. RESULTS—The load group reached a peak in free insulin value (460 μU/ml) within 5 min and plateaued at 88 μU/ml in 60 min. The twice no load group reached a peak (200 μU/ml) at 45 min. The no load group reached a peak (60 μU/ml) in 60–120 min. Five patients in the no load group required supplemental insulin doses to decrease initial glucose levels by 10%; patients in the twice no load and load groups did not. Except for these differences, times to reach glucose ≤250 mg/dl, pH ≥7.3, and HCO(3)(−) ≥15 mEq/l did not differ significantly among the three groups. CONCLUSIONS—A priming dose in low-dose insulin therapy in patients with DKA is unnecessary if an adequate dose of regular insulin of 0.14 unit · kg body weight(−1) · h(−1) (about 10 units/h in a 70-kg patient) is given.