Substrate mobilisation during surgery. A comparison between halothane and fentanyl anaesthesia.

A study was undertaken in twenty-eight patients to compare the effects of the supplementation of nitrous oxide and oxygen anaesthesia with either 0.5--1.0% halothane or 50 microgram fentanyl/kg on the metabolic and hormonal response to gynaecological surgery. The results showed that the increases in blood glucose, plasma cortisol and growth hormone concentrations observed in the halothane group of patients were abolished in those who received fentanyl. It is postulated that the ability of large doses of fentanyl to inhibit the cortisol and growth hormone response to surgery may be of value in ameliorating the catabolic response to trauma.