Hormonal and metabolic changes during hypothermic coronary artery bypass surgery in diabetic and non-diabetic subjects.

Hormonal and metabolic responses to hypothermic coronary artery bypass grafting (CABG) were studied in three groups: 8 non-diabetic patients, 8 patients with non-insulin-dependent diabetes mellitus (NIDDM) given a glucose pump priming solution and 8 NIDDM patients given a non-glucose infusion. There were no significant differences in stress hormone responses between NIDDM and non-diabetic patients, with adrenaline concentrations rising 10-fold, noradrenaline 4-fold and cortisol 2 to 3-fold. Glucagon rose significantly during bypass only in the NIDDM patients who did not receive a glucose prime. Comparable marked hyperglycaemia was seen in both glucose primed groups during bypass and exclusion of glucose from the prime in NIDDM patients prevented this major rise. Postoperatively, the rise in insulin in the glucose primed NIDDM patients contrasted with the slower rise in the non-glucose primed NIDDM patients who were also hyperglycaemic by this stage. Perioperative hyperglycaemia in NIDDM patients undergoing CABG can be prevented by using a non-glucose priming solution and by giving insulin infusion, particularly postoperatively.