[The effect of enflurane anaesthesia and operation on the sympathoadrenal and adrenocortical system (author's...

The effect of enflurane anaesthesia on the sympathoadrenal system, the hypothalamic-hypophyseal-adrenocortical system, and on the circulatory system was investigated in patients undergoing ophthalmic surgery. Blood concentrations of adrenaline, noradrenaline, ACTH, cortisol, and arterial blood pressure and heart rate were measured in 10 patients 30 min after premedication (I), 3-5 min after surgical incision (II), 20 or 45 min after surgical incision (III) and in 7 of 10 patients 10-15 min after extubation (IV). After conventional induction anaesthesia was maintained with enflurane (1.5-2.0%), combined with N2O/O2 2:1, and intermittent relaxation. Plasma adrenaline, ACTH, cortisol and heart rate increased significantly during operation, while plasma noradrenaline and blood pressure did not change significantly. Thus enflurane anaesthesia could not completely inhibit the increased activity of sympathoadrenal and hypothalamic-hypophyseal-adrenocortical system caused by surgical stress.