Total intravenous anesthesia. Midazolam-fentanyl vs enflurane-nitrous oxide

This study was done to compare the hemodynamics, serum catecholamine levels and postoperative analgesia in total intravenous anesthesia with inhalation anesthesia. Thirteen patients for elective upper abdominal surgery, aged from 40 to 75 years, were studied. In the total intravenous anesthesia group (TIVA group, 7 patients), anesthesia was induced with 0.3 mg.kg-1 midazolam and maintained with 0.68 mg.kg-1.hr-1 midazolam for 15 minutes followed by 0.125 mg.kg-1.hr-1. Fentanyl was also administered as necessary. In the inhalation anesthesia group (inhalation group, 6 patients), anesthesia was induced with 5 mg.kg-1 thiamylal and maintained with 0.5-2.0% enflurane and 66% nitrous oxide in oxygen. In the TIVA group, the blood pressure and heart rate were as stable as those in the inhalation group. The serum concentration of catecholamines in the TIVA group rose significantly 60 minutes after intubation, in particular, the serum epinephrine level was higher than in the inhalation group. The time for extubation, respiratory rate and PaCO2 were not different between the two groups. The postoperative analgesic duration in the TIVA group was significantly longer than that in the inhalation group. The elimination half-life of midazolam was 1.675 +/- 0.281 hours in the TIVA group. In this study, TIVA failed to suppress the elevation of serum catecholamine levels, but it achieved stable hemodynamics during upper abdominal surgery and enough postoperative analgesia without affecting the extubation time, the respiratory conditions and the elimination half-life of midazolam.