[Comparative study of the efficacy and tolerance of propofol and thiopental in induction and in continuous perfusion with neuroleptanesthesia].

We have studied 40 ASA I/II patients aged from 18 to 65 years undergoing otorhinolaryngologic surgery of 40-100 minutes of duration. Patients were randomly assigned to two groups. Anesthesia in group I was induced with thiopental, 4 mg/kg and maintained with N2O at 66% and a variable perfusion of fentanyl. In group II, anesthesia was induced with propofol, 2.5 mg/kg and maintained with a perfusion of 6-12 mg/kg/hour and an initial perfusion of fentanyl, 4 micrograms/kg/hour. Loss of consciousness occurred in 37.49 +/- 9.78 seconds in group I and in 46.25 +/- 12.62 seconds in group II, with no significant differences. Two minutes after induction, propofol group presented a significant decrease in systolic blood pressure of - 12 mm Hg and both groups presented comparable increases in systolic blood pressure and heart rate during intubation. Five minutes later, systolic blood pressure regained normal values. Maintenance in group II was achieved in a proper fashion with a mean propofol consumption of 9.5 +/- 2.6 mg/kg/hour and fentanyl consumption of 4.94 +/- 2.22 micrograms/kg/hour whereas in group II, with N2O at 66%, the amount of fentanyl required was 6.85 +/- 2.95 micrograms/kg/hour, which was significantly higher. Eye opening from the time of interruption of anesthetics was achieved at 6.6 +/- 3.2 minutes in group I and 12.44 +/- 6.34 in group II. Consciousness was regained at 11.25 +/- 3.96 and 16.87 +/- 6.95 minutes, respectively. Pain on injection occurred in 15% with propofol and in 10% with thiopental. No patient presented major complications nor phlebitis after administration of the anesthetic.