Metabolic effects of anaesthesia: effect of thiopentone-nitrous oxide anaesthesia on human growth hormone and insulin levels in plasma.

Abstract

The present study was undertaken to investigate the effects of thiopentone nitrous oxide anaesthesia alone on carbohydrate and fat metabolism in 33 subjects, by determining plasma growth hormone (hgh), insulin, blood glucose and free fatty acids (ffa), and to compare these with the effects of anaesthesia plus surgery. Determination of plasma growth hormone and insulin levels was made by radioimmunoassay utilizing I125 labelled hormones. Determinations of plasmahgh, insulin, blood glucose, andffa were made simultaneously before induction of thiopentone nitrous oxide anaesthesia; 15, 30, and 45 minutes after induction of anaesthesia; 15, 30, 60, and 120 minutes after the start of surgery, and in the postoperative period when the patient was adequately awake in the recovery room. Plasmahgh levels were not changed appreciably (1.5 mμg/ml) during thiopentone nitrous oxide alone for 45 minutes. They increased and reached a peak (107 mμg/ml) one hour after the start of operation. Plasma insulin levels increased in the control group, but they did not change appreciably during anaesthesia or surgery. Blood glucose levels were increased by glucose load during anaesthesia, but the magnitude of elevation in blood glucose was similar to that of control group, which indicates absence of hyperglycaemic effect of thiopentone anaesthesia. Blood glucose increased significantly during surgery. Plasmaffa levels did not change significantly during the entire course of anaesthesia or surgery. These findings suggest that thiopentone-nitrous oxide anaesthesia is the method of choice for diabetic patients.