Insulin infusion therapy in critical care patients: Regular insulin vs short-acting insulin. A prospective, crossover, randomized, multicenter blind study

Abstract Introduction The aim of this multicenter, prospective, randomized, crossover trial is to compare, in critical care patients receiving insulin infusion therapy (IIT), the pharmacodynamic of Humulin insulin (Hlin), currently used as “standard of care,” and Humalog insulin (Hlog), a shorter acting insulin formulation. This was measured as extent and duration of the carryover effect of insulin treatment, with the latter calculated as ratio between blood glucose concentration (BGC) reduction during and after IIT. Materials and methods Twenty-eight patients treated in an intensive care unit and receiving full nutritional support were randomly assigned to Hlin or Hlog as first treatment. Insulin was infused at a constant rate in patients presenting with BGC greater than or equal to 180 mg/dL (0.04 U/kg per hour) and was discontinued when BGC was less than or equal to 140 mg/dL (therapeutic BGC drop). Further reductions in BGC after discontinuation of insulin infusion were recorded (postinfusional BGC drop). During the study period, whole blood BGC was measured every 30 minutes. A minimal 6-hour washout interval was maintained between treatments with the 2 types of insulin. The primary end point was the extent (calculated as ratio between the therapeutic BGC drop and the postinfusional BGC drop) and duration of the carryover effect. Results Treatment with Hlog, as compared with Hlin, was associated with a less profound carryover effect as well as a briefer duration of carryover (median, 0.40 vs 0.62; P < .001; median, 1 vs 1.5 hours; P < .001). Conclusions The use of constant Hlog infusion for IIT, when compared with Hlin at the same dose, is associated with a less profound carryover effect on BGC after discontinuation of IIT, a briefer duration of carryover, a faster BGC drop during infusion, and a quicker BGC rise after discontinuation. These characteristics suggest that Hlog IIT may be preferable for use in critically ill patients.