Canadian Journal of Anesthesia, Vol 17, 347-358, Copyright © 1970 by Canadian Anesthesiologists' Society

Effect of Methoxyflurane Anaesthesia and Surgery on Human Growth Hormone and Insulin Levels in Plasma

¹ Department of Anaesthesiology, Hirosaki University School of Medicine, Hirosaki, AomariKen, Japan

The present study was undertaken to investigate the effects in 20 patients of methoxyflurane anaesthesia alone on carbohydrate and fat metabolism by determining plasma growth hormone (HGH), insulin, blood glucose, free fatty acids (FFA), and cortisol, and to compare these with the effects of anaesthesia plus surgery. Analysis of plasma growth hormone and insulin levels was made by radioimmunoassay utilizing I¹²⁵ labelled hormones.

Determinations of plasma HGH, insulin, cortisol, FFA, and blood glucose were made simultaneously before induction of methoxyflurane anaesthesia, 15, 30, and 45 minutes after induction of anaesthesia, 5-10, 30, and 60 minutes after the start of surgery, and in the postoperative period when the patient was adequately awake in the recovery room.

Plasma HGH levels during methoxyflurane anaesthesia alone significantly increased for 45 minutes from a control level of 1.4 ± 0.5 mµg/ml to 6.0 ± 1.6 mµg/ml. They further increased and reached a peak (8.0 ± 1.5 mµg/ml) one hour after the start of operation. Plasma insulin levels did not change appreciably during anaesthesia or surgery.

Blood glucose levels did not alter markedly but increased gradually during surgery. Plasma FFA levels did not change markedly during the entire course of anaesthesia or surgery. Plasma cortisol levels increased stepwise and significantly during surgery. The pattern of elevation in plasma HGH was different from that of plasma cortisol.