Postoperative hyperglycemia: clinical benefits of insulin therapy

The hormonal changes associated with surgical stress induce a number of metabolic changes in both nondiabetic and diabetic patients. In nondiabetic patients hyperinsulinemia and hyperglycemia develop, and in diabetic patients hyperglycemia and hypoinsulinemia develop from diminished or lack of islet cell function. The goal for the diabetic patient immediately after surgery is to keep metabolism as nearly normal as possible. Methods to achieve normoglycemia are a matter of physician preference, but failure to maintain physiologic control subjects these patients to a wide range of abnormalities. Insulin deficiency and hyperglycemia modify general metabolism, impair protein synthesis and ion regulation, predispose to neural damage, interfere with blood cell functions, and alter drug detoxification. If exogenous insulin is necessary, intravenous administration has gained wide acceptance, but the subcutaneous route produces satisfactory results. Frequent and accurate blood glucose monitoring is crucial to adjustment of insulin doses for restoration and maintenance of normoglycemia in the postoperative period.