PROPOFOL VS ISOFLURANE - ENDOCRINE STRESS -RESPONSE, HEMODYNAMIC REACTION, AND RECOVERY AFTER TOTAL INTRAVENOUS AND INHALATION ANESTHESIA

This prospective, randomised study compared total intravenous anaesthe sia (TIVA) and inhalation anaesthesia with respect to endocrine stress response, haemodynamic reactions, and recovery. Methods. The investig ation included two groups of 20 ASA I-II patients 18-60 years of age s cheduled for orthopaedic surgery. For premedication of both groups, 0. 1 mg/kg midazolam was injected IM. Patients in the propofol group rece ived TIVA (CPPV, PEEP 5 mbar, air with oxygen, F(i)O2 33%) with propof ol (2 mg/kg for induction followed by an infusion of 12-6 mg/kg.h) and fentanyl (0.1 mg before intubation, total dose 0.005 mg/kg before sur gery, repetition doses 0.1 mg). For induction of patients in the isofl urane-group, 5 mg/kg thiopentone and 0.1 mg fentanyl was administered. Inhalation anaesthesia was maintained with 1.2-2.4 vol.% isoflurane i n nitrous oxide and oxygen at a ratio of 2:1 (CPPV, PEEP 5 mbar). For intubation of both groups, 2 mg vecuronium and 1.5 mg/kg suxamethonium were injected, followed by a total dose of 0.1 mg/kg vecuronium. Bloo d samples were taken through a central venous line at eight time point s from before induction until 60 min after extubation for analysis of adrenaline, noradrenaline (by HPLC/ECD), antidiuretic hormone (ADH), a drenocorticotropic hormone (ACTH), and cortisol (by RIA). In addition, systolic arterial pressure (SAP), heart rate (HR), arterial oxygen sa turation (SpO2), and recovery from anaesthesia were observed. Results. Group mean values are reported; biometric data from both collectives were comparable (Table 1). Plasma levels of adrenaline (52 vs. 79 pg/m l), noradrenaline 146 vs. 217 pg/ml), and cortisol (82 vs. 165 ng/ml) were significantly lower in the propofol group (Table 2, Figs. 1 and 3 ). Plasma levels of ADH (4.8 vs. 6.1 pg/ml) and ACTH (20 vs. 28 pg/ml) did not differ between the groups (Table 2, Figs. 2 and 3). SAP (128 vs. 131 mmHg) was comparable in both groups, HR (68/min vs. 83/min) wa s significantly lower in the propofol group, and SpO2 (97,7 vs. 97,4%) showed no significant difference (Table 3). Recovery from anaesthesia was slighly faster in the propofol group (following of simple orders 1.9 vs. 2.4 min, orientation with respect to person 2.4 vs. 3.4 min, o rientation with respect to time and space 2.8 vs. 3.7 min), but differ ences failed to reach statistical significance. Conclusions. When comp ared with isoflurane inhalation anaesthesia, moderation of the endocri ne stress response was significantly improved during and after TIVA wi th propofol and fentanyl. Slightly shorter recovery times did not lead to an increased stress response. With respect to intra- and postopera tive stress reduction, significant attenuation of sympatho-adrenergic reaction, comparable SAP and reduced HR, sympatholytic and hypodynamic anaesthesia with propofol and fentanyl seems to be advantageous for p atients with cardiovascular and metabolic disorders. For this aim, car eful induction and application of individual doses is essential.