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 micrograms 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 for 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 not catheterized during operation.