[Bispectral index based comparison of propofol dose requirement combined with various types of analgesic methods for total intravenous anesthesia].

We hypothesized that propofol dose requirement for total intravenous anesthesia is varied with the analgesic methods during anesthesia if the depth of anesthesia is maintained at the same level with bispectral index. Adult gynecological patients without any complications were randomly allocated to four groups; propofol with 1) continuous epidural block-oxygen-nitrous oxide (n = 18), 2) continuous epidural block-oxygen-air (n = 21), 3) fentanyl (total 5 micrograms.kg-1)-oxygen-nitrous oxide (n = 18) and 4) fentanyl (total 5 micrograms.kg-1)-oxygen-air (n = 21) group. Propofol 1.5 mg.kg-1 and vecuronium 0.15 mg.kg-1 were administered intravenously for endotracheal intubation. Propofol was titrated to maintain bispectral index between 40 and 60. Total dose of propofol except the dose for induction was compared among the groups with one-way ANOVA and Scheffé's F test and P < 0.05 was considered as significant. Results were expressed as means +/- SDs. The age, body weight, height and hemodynamic changes during anesthesia among the groups were not significantly different. Total required dose of propofol for continuous epidural block-oxygen-nitrous oxide, continuous epidural block-oxygen-air, fantanyl-oxygen-nitrous oxide and fentanyl-oxygen-air group were 4.78 +/- 0.87 mg.kg-1.h-1, 6.10 +/- 0.93 mg.kg-1.h-1, 5.79 +/- 0.75 mg.kg-1.h-1 and 6.58 +/- 1.19 mg.kg-1.h-1, respectively. Nitrous oxide was able to reduce the dose of propofol significantly either with epidural anesthesia or fentanyl used for analgesia.