EFFECT OF HIGH-DOSE FENTANYL ANAESTHESIA ON THE METABOLIC AND ENDOCRINE RESPONSE TO CARDIAC SURGERY

The effect of high-dose fentanyl anaesthesia (75ugkg~') on the metabolic and endocrine responses to cardiac surgery was compared with results obtained in similar patients who had received incremental doses of papaveretum. High-dose fentanyl anaesthesia prevented the increases in blood glucose, plasma cortisol and plasma growth hormone concentrations found before cardiopulmonary bypass, but during cardiopulmonary bypass was only effective in decreasing the hyperglycaemia. The continued administration of fentanyl following operation failed to suppress the hormonal and metabolic changes so that the total urinary excretion during the first 5 days after surgery was similar in both groups of patients. High-dose fentanyl anaesthesia was associated with only transient metabolic benefits confined to the period during operation. There has been considerable interest recently in the use of high-dose fentanyl anaesthesia to decrease or abolish the metabolic and endocrine responses to surgery (Editorial, 1979; Editorial, 1980). Although Hall and colleagues (1978) showed that fentanyl 50|igkg~ ' body weight abolished the changes in plasma cortisol, growth hormone (GH), and blood glucose concentrations associated with prolonged pelvic surgery, Cooper and co-workers (1981), also using fentanyl 50ugkg~ ' for gastric surgery, observed only a transient decrease in the metabolic and hormonal changes. Stanley and colleagues have undertaken several studies using high-dose fentanyl for cardiac surgery and claim that the technique improves cardiovascular stability (Stanley and Webster