COMPARISON OF CAUDAL BUPIVACAINE, BUPIVACAINE MORPHINE AND BUPIVACAINE-MIDAZOLAM MIXTURES FOR POSTOPERATIVE ANALGESIA IN CHILDREN

Sixty children undergoing inguinal or urogenital surgery were allocate d randomly to three groups to receive a caudal injection of either 0.1 25% bupivacaine 0.75 mL kg(-1) with 0.5% midazolam 50 mu g kg(-1) (n=2 0) or with 1% morphine chlorhydrate 0.05mg kg(-1) (n= 20), or bupivaca ine alone (n=20) after surgery under general anaesthesia. There were n o significant changes in heart rate, blood pressure, respiratory rate or oxygen haemoglobin saturation values in all groups, and there were no significant differences in the incidence of vomiting and pruritus b etween the groups (P>0.05). Sedation scores were higher in the bupivac aine-midazolam and the bupivacaine-morphine groups than in the bupivac aine group at 8-12 h post-operatively (P>0.01). The durations of analg esia were 21.15+/-1.2h in the bupivacaine-midazolam group, 14.50+/-1.6 h in the bupivacaine-morphine group and 8.15+/-1.3 h in the bupivacain e group. Differences between the bupivacaine-midazolam group and the b upivacaine group (P<0.001), the bupivacaine-midazolam group and the bu pivacaine-morphine group (P<0.01),, and the bupivacaine-morphine group and the bupivacaine group (P<0.01) were significant. It is suggested that caudal administration of a bupivacaine-midazolam mixture produces a longer duration of post-operative analgesia than a bupivacaine-morp hine mixture and bupivacaine alone with sedation for 8-12 h post-opera tively.