INTRAVENOUS ANESTHESIA WITH PROPOFOL VERSUS THIOPENTONEENFLURANE - ANANALYSIS OF CONSUMPTION AND COSTS

It may be possible to reduce costs in anaesthesia when there is a choi ce of drugs and methods. Two of the most widespread techniques are inh alation anaesthesia with enflurane following induction with thiopenton e, and intravenous anaesthesia (IVA) with propofol. The aims of our st udy were to compare the costs, effectiveness and side effects of the a naesthetics involved in these two techniques, and to measure significa nt clinical parameters. Methods. After approval by the hospital ethics committee, 40 adult patients of ASA physical status 1 and 2 who had b een scheduled for elective septorhinoplasty and had given informed con sent were entered in our prospective, single-blind randomized study. I n 20 patients anaesthesia was induced with thiopentone (4-5 mg/kg) and suxamethonium (1-1.5 mg/kg) and maintained with enflurane. The other 20 patients received an initial i.v. bolus of propofol (2-2.5 mg/kg) f ollowed by a propofol infusion adjusted to their individual clinical n eeds. Ventilation was performed in both groups with 70% nitrous oxide in oxygen, using a nonrebreathing system. Muscle relaxation was mainta ined with atracurium. The amounts of anaesthetics, oxygen, nitrous oxi de, and muscle relaxants used were measured and a record of the costs was kept. In addition, circulatory and respiratory parameters and quan titative and qualitative aspects of recovery from anaesthesia were rec orded. Results. The biometric and clinical data did not differ signifi cantly bet between the two groups. For induction, 382 (+/-55.9) mg thi opentone costing 1.24 Swiss francs (SFr), or 172 (+/-25.1) mg propofol costing 11.87 (SFr) was used. For maintenance, 28.3 (+/-6.4) ml enflu rane costing 21.96 SFr/h, or 450.7 (+/-247) mg propofol costing 29.75 SFr/h was required. The need for muscle relaxants, oxygen, and nitrous oxide was also not significantly different in the two groups. Additio nal expenses were due to relaxation antagonists (1.91 SFr per patient in both groups) and to the perfusion pump system (8.60 SFr per patient in the IVA group only). Circulatory and respiratory parameters remain ed normal in both groups. In the propofol group, the heart rate tended to increase more at the beginning of anaesthesia, whereas later on it showed a tendency to lower values than in the thiopentone/enflurane g roup. Patients receiving IVA generally had a shorter awakening period, a higher degree of wellbeing during recovery, and needed less systemi c analgesics (P<0.05). Conclusions. Costs of anaesthetic drugs in the IV group totalled 54.50 SFr during the first hour, i.e. 1.65 times the costs in the thiopentone/enflurane group for the same time. However, with continuing duration of anaesthesia this ratio declines to 1.43 in anaesthesia lasting 2 h. In addition, IVA patients had a noticeably f aster and far more pleasant recovery. Minute ventilation, oxygen consu mption, heart rate and CO2 production indicated a less pronounced stre ss response and sympathetic activity during and after propofol. Quicke r recovery of cognitive and psychomotor abilities, less postoperative pain and less impairment of respiratory function after IVA may lead to an earlier release from the postoperative recovery unit. This might b e a cost-reducing factor that should be taken into account when these two anaesthetic regimens are concerned.