COMPARISON OF THE EFFECTS OF ADRENALINE, CLONIDINE AND KETAMINE ON THE DURATION OF CAUDAL ANALGESIA PRODUCED BY BUPIVACAINE IN CHILDREN

Sixty boys, aged 1-10 yr, undergoing orchidopexy were allocated randomly to receive one of three solutions for caudal extradural injection. Group A received 0.25% bupivacaine 1 ml kg(-1) with adrenaline 5 mu g ml(-1) (1/200 000), group C received 0.25% bupivacaine 1 ml kg(-1) with clonidine 2 mu g kg(-1) and group K received 0.25% bupivacaine 1 ml kg(-1) with ketamine 0.5 mg kg(-1). Postoperative pain was assessed using a modified objective pain score and analgesia was administered if this score exceeded 4. The median duration of caudal analgesia was 12.5 h in group K compared with 5.8 h in group C (P < 0.05) and 3.2 h in group A (P < 0.01). There were no differences between the groups in the incidence of motor block, urinary retention or postoperative sedation.