Metabolic perioperative management: novel concepts

Abstract

This review summarizes novel information regarding the role of metabolic control in the perioperative period. Managing perioperative metabolism has recently been shown to be an important way to improve outcomes in surgical care. In particular, postoperative insulin resistance and hyperglycemia have been linked to many common complications. Recent studies have explored the toxicity of hyperglycemia and suggest a causal relation between insulin resistance and complications in the postoperative state. Controlling glucose concentrations with insulin has been shown to also improve protein balance and fat metabolism. In addition, insulin may affect other hormones including insulinlike growth factor-I during surgical stress. Lastly, recent data suggest that hyperglycemia plays an important role in aggravating the inflammatory response, in that overflow of substrates in the mitochondria causes the formation of excess free oxygen radicals and may also alter gene expression to enhance cytokine production. Although overcoming insulin resistance by insulin infusion is one way of combating hyperglycemia, prevention of its development can also be achieved by using epidural blockade to reduce the release of adrenal stress hormones and to control pain, by preoperative carbohydrates instead of overnight fasting, and by minimal invasive surgical techniques. Minimizing the effects of insulin resistance has been shown to substantially improve outcome after surgical stress.