Insulin in the management of the diabetic surgical patient: continuous intravenous infusion vs subcutaneous administration.

A prospective randomized study comparing constant intravenous infusion of regular, low-dose insulin versus conventional subcutaneous administration of neutral protein Hagedorn (NPH) insulin in insulin-requiring patients undergoing orthopedic procedures under general anesthesia was undertaken. The degree of diabetic control was better in those receiving constant 2 units/hour of regular insulin than in those receiving two thirds of daily maintenance doses of NPH insulin. However, in two of eight patients receiving 2 units/hour, decreased insulin infusion rates and increased dextrose infusion rates were required to avoid hypoglycemia. Preoperative NPH insulin and 1 unit/hour insulin administration resulted in equivalent diabetic control.