A comparison of two types of anaesthesia on the endocrine and metabolic responses to anaesthesia and surgery.

Abstract

The influence of halothane-nitrous oxide anaesthesia and normotensive epidural analgesia (level of sensory block T8-T10), respectively, on the plasma concentrations of adrenocorticotrophic hormone (ACTH), beta-lipotropin (beta-LPH), cortisol, dehydroepiandrosterone (DHA) and aldosterone as well as on the metabolites glucose, lactate and free fatty acids (FFA) was studied in 20 healthy patients who underwent elective orthopaedic procedures on the lower limbs. ACTH and beta-LPH concentrations in plasma rose significantly (P less than 0.001) during halothane-nitrous oxide anaesthesia. DHA secretion closely followed the secretory profile of cortisol. Increased renin levels and increased ACTH release seemed to be responsible for increased aldosterone secretion, intra-operatively. The hormonally induced rise of glycogenolysis and lipolysis did not produce important intra-operative increases in metabolite concentrations in the blood. In normotensive epidural analgesia no significant increase in stress response could be demonstrated, even with low levels of sensory block.