The effect of high-dose fentanyl anaesthesia (75 micrograms kg-1) 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.

No abstract

The effect of the infusion of phentolamine 0.5 mg min-1 on the metabolic response to gynaecological surgery was investigated. In comparison with the control group of patients, phentolamine was associated with a significant increase in plasma insulin concentration after 30 and 60 min of surgery. The glycaemic response to surgery was decreased by alpha-adrenergic blockade, but this was only significant after 120 min of surgery. The hypotension produced by the administration of phentolamine was well tolerated.

The effects of infusion i.v. of 0.9% sodium chloride solution, Hartmann's and 5% dextrose solution on the concentrations of circulating metabolites and insulin were compared in patients undergoing cholecystectomy. Hartmann's solution had a similar effect on the metabolic response to 0.9% sodium chloride solution, but the use of 5% dextrose was associated with an exacerbation of the hyperglycaemic response to surgery. Plasma insulin concentrations increased significantly in the group receiving 5% dextrose showing that the usual suppression of insulin during abdominal surgery can be overcome by a strong glycaemic stimulus.

The effects of the i.v. infusion of insulin, 70 mu. kg-1h-1 for the first 60 min and 35 mu. kg-1h-1 subsequently, on the metabolic and endocrine responses to gynaecological surgery were investigated. In comparison with a control group of patients, the insulin infusion caused a marked decrease in circulating glucose, non-esterified fatty acids and beta-hydroxybutyrate concentrations, and an increase in blood lactate values. The plasma cortisol response to surgery was unaffected by the decrease in blood glucose, but the growth hormone response was increased. Heart rates and arterial pressures during surgery were not altered by the metabolic changes associated with insulin infusion, but there was a greater decrease in aural temperature. The results demonstrate the importance of insulin suppression during surgery in mediating changes in circulating metabolites.