Background and Goal of Study: The purpose of this study was to compare the effect between remifentanil infusion and epidural analgesia on desflurane requirements using bispectral index (BIS) in patients who underwent urological procedures (prostatectomies, cystectomies).
Materials and Methods: Thirty patients ASA I-III, aged 60-85 were randomly assigned to the remifentanil group (group A) which received continuously i.v. remifentanil (0.15-0.25 μg/kg/min) or the epidural group (group B) which received epidurally (O1-O3) a local anaesthetic ropivacaine 0.75% followed by boluses if needed throughout the operation. Anaesthesia was maintained with desflurane with fresh gas flow 2 L/min (60% N2O in O2). The end tidal concentration of desflurane was titrated so that BIS values to range between 45-60. The median end tidal desflurane was calculated in each patient when BIS was in the desired range every 5 minutes. For statistical analysis was used the paired sampled t-test. A threshold p value of 0.05 was set to determine the statistically significant differences.
The two groups were comparable with respect to demographic characteristics, haemodynamic variables and BIS values throughout the study.
Results and Discussion: The required end tidal concentration of desflurane in the remifentanil group was significantly lower p < 0.05 compared with the epidural analgesia group (1.6 (0.5) vs 2.43 (0.82) respectively).
Conclusion: In conclusion the end tidal concentration of desflurane required to maintain BIS values 45-60 is higher when analgesia is maintained with epidural block versus analgesia obtained with i.v. infusion of remifentanil in patients who underwent urological procedures.
1 Guignard B, Menigaux C, Dupont C et al. Anesth Analg 2000; 90: 161-7.
2 Johansen J, Sebel P. Anestesiology 2000; 93:1336-44.