Comparison of caudal bupivacaine and diamorphine with caudal bupivacaine alone for repair of hypospadias

Forty-five boys undergoing repair of hypospadias were allocated randomly to one of two groups. After induction of anaesthesia, 22 patients received 0.25% caudal bupivacaine 0.5 ml kg(-1) and diamorphine 30 mu g kg(-1) and the remaining 23 patients received 0.25% caudal bupivacaine 0.5 ml kg(-1) alone. Pain scores (Children's Hospital of Eastern Ontario Pain Scale), sedation scores, ventilatory frequency, analgesic requirements and associated side effects were recorded or the first 24 h after operation, The two groups were indistinguishable in age, weight and duration of surgery. There was a statistically significant reduction in early pain scores. There was also a statistically significant increase in the time to first passage of urine in those boys in the diamorphine group who were no? catheterized during operation.