A prospective, double-blind, randomized trial of caudal block using ropivacaine 0.2% with or without fentanyl 1 microg kg-1 in children

Background. It has been reported that ropivacaine produces vasoconstrictionin contrast to vasodilation produced by bupivacaine. It is possiblethat additives to ropivacaine can provide further analgesicadvantages compared with bupivacaine. We thus evaluated whetherthe addition of fentanyl to ropivacaine prolonged the durationof analgesia after a single shot caudal block. Methods. A total of 36 children undergoing surgical proceduresbelow the umbilicus were randomly allocated to one of two groups:Group F received ropivacaine 0.2%, 1 ml kg^–1 with fentanyl1 µg kg^–1 and Group S received ropivacaine 0.2%,1 ml kg^–1 with saline. The analgesic effect of the caudalblock was evaluated using the Children's Hospital of EasternOntario Pain Scale (CHEOPS) and sedation was assessed usingthe Steward score at 30 min after extubation and at 1, 2, 4,6, 12 and 24 h. The first analgesic requirement time and side-effectsin a 24 h period were also recorded. Results. There were no differences in characteristics betweenthe groups. The end-tidal concentration of sevoflurane at extubationin Group F was significantly lower than in Group S. However,there was no significant difference in time from discontinuationof the volatile anaesthetics to tracheal extubation. No statisticaldifferences were found in the CHEOPS and Steward score, andthe time to first analgesia. The incidence of postoperativevomiting was not significantly different. Conclusion. We found that the addition of fentanyl 1 µgkg^–1 to ropivacaine 0.2% for caudal analgesia providesno further analgesic advantages over ropivacaine 0.2% alone.