Comparison of clonidine 1 mu g kg(-1) with morphine 30 mu g kg(-1) for post-operative caudal analgesia in children

In a prospective randomized study in children, we compared caudal bupivacai ne-clonidine with bupivacaine-morphine to evaluate whether clonidine can be used as an alternative to morphine in caudal anaesthesia. Caudal anaesthes ia was administered in 36 children undergoing orchidopexy, hernia repair or circumcision, using 1.5 mL kg(-1) bupivacaine 0.18% with either 1 mu g kg( -1) clonidine (group 1) or 30 mu g kg(-1) morphine (group 2). Haemodynamic and respiratory parameters, anaesthetic requirements, recovery time and pai n score were monitored for 24 h. Eleven children in group 1 and nine childr en in group 2 did not need any supplementary systemic analgesics throughout the 24-h observation period. Mean (+/- SD) duration of analgesia in the re maining patients was 6.3 h (+/- 3.3 h) in group 1 and 7.1 h (+/- 3.4 h) in group 2 (P=0.43). Recovery time after anaesthesia was significantly longer in group 1 (16.6 +/- 8.8 min) than in group 2 (11.5 +/- 4.7 min) (P < 0.05) . We conclude that analgesia provided by 1 mu g kg(-1) clonidine added to c audal bupivacaine is comparable with that provided by 30 mu g kg(-1) caudal morphine with bupivacaine. Clonidine at this low dose did not cause respir atory depression.