Current Concepts and Future Perspectives in the Optimization of Perioperative Blood Glucose Levels and Improvement of Outcomes

Diabetes is defined as a clinical syndrome consisting of constellation of signs and symptoms as a result of hyperglycemia, which results from absolute or relative deficiency of insulin, accompanied by absolute or relative excess of glucagon. Unfortunately, perioperative hyperglycemia has been associated with the greater risk of postoperative morbidity and mortality. On the other hand, hypoglycemia is equally dangerous. The adverse consequences of hypoglycemia include those on circulatory, autonomic, and central nervous systems Several studies have concluded that adequate glycemic control without excessive hyper- or hypoglycemia, has been associated with an improved surgical outcome. The controversy continues to exist in the context of establishment of target blood glucose levels and protocolization of the generalized indications for intensive insulin therapy initiation. This review article addresses the ever debatable issue on perioperative glycemic control in diabetic patients and focuses on recent advances and updates in the optimization of perioperative blood glucose levels, merits and demerits of various perioperative regimens, with recent studies on the effects of optimal perioperative glucose control on morbidly obese patients undergoing bariatric surgery, and additional recent studies on preoperative HbA1c and the associated risk of postoperative complications in patients undergoing oncosurgery. It has been recently observed that intra-operative hyperglycemia predisposed towards increase in the odds for postoperative hyperglycemia Therefore, an early and aggressive management of raised intra operative glucose levels, results in lower starting blood glucose concentrations for postoperative glucose management. The age and BMI also have significant positive effects on raised postoperative glucose levels. Also, initiation of insulin infusion early, at or more than 140 mg/dl blood glucose levels, does not increase the incidence of hypoglycemia. In conclusion, a protocol for perioperative regime should be flexible and common sense must be applied at every step during the perioperative management of a diabetic patient scheduled to undergo a major surgery.