[N2O-supplemented intravenous anesthesia versus inhalation anesthesia. A comparative study of the sympathoadrenergic reaction and postoperative vigilance].

The aim of the present study was a comparison of the intraoperative sympathoadrenergic response and the postoperative vigilance of a propofol/alfentanil anaesthesia to a conventional isoflurane anaesthesia. 25 patients were admitted to the study undergoing septorhino surgery. Patients with continuous intravenous anaesthesia with propofol/alfentanil combined with nitrous oxide showed better haemodynamic conditions without an increase of blood pressure and catecholamines under laryngoscopy, intubation and surgical stimulation. In contrast to that the patients with isoflurane anesthesia showed a significant increase in haemodynamic parameters and capillary bloodflow. The measured plasma adrenalin levels showed wide intraindividual fluctuation but no significant difference between the groups. The suppression of plasma noradrenaline was more pronounced under intravenous anaesthesia. Recovery was significantly faster and vigilance significantly better in the patients undergoing intravenous anaesthesia. After 30 min patients with i.v. anaesthesia fulfilled all the conditions to be transferred to the regular ward; the other group needed more than one hour. It can be concluded that continuous i.v. anaesthesia with propofol/alfentanil is superior in suppressing the stress response to invasive stimuli and provides faster recovery and better postoperative analgesia.