Carbohydrate and lipid metabolism in open-heart surgery

Carbohydrate and lipid metabolism was studied in 8 patients who underwent open-heart surgery with the aid of extracorporeal circulation. Hyperglycemia was observed during perfusion. Despite the high glucose levels during perfusion, insulin responses were depressed. A rise of insulin levels was observed one hour after perfusion, and at the same time the glucose levels dropped. Suppression of insulin secretion during perfusion may be the result of increased catecholamine secretion, induced hypothermia, or heparin administration. High levels of non-esterified fatty acids (NEFA) and low levels of triglycerides were observed immediately before, during, and after perfusion while heparin was being utilized. This phenomenon was considered to be strongly affected by the use of heparin. The levels of growth hormone were depressed during perfusion but significantly elevated one hour after the end of perfusion. These phenomena may be caused by the fluctuations in glucose and NEFA levels.