Caudal Additives Do Not Improve the Analgesia Afforded by Levobupivacaine After Hypospadias Repair

BACKGROUND Caudal analgesia is commonly employed to provide excellent intra- and postoperative analgesia for primary hypospadias repair in children. Several additives to local anesthetics are commonly employed to increase the block duration, although these have uncertain benefits. OBJECTIVES This study investigated whether, in caudal analgesia with levobupivacaine 0.25%, the addition of S (+)-ketamine, clonidine, or both agents combined, would prolong postoperative analgesia in patients undergoing primary hypospadias repair. PATIENTS AND METHODS We conducted a retrospective chart analysis for all patients who underwent hypospadias repair with caudal analgesia over a consecutive 3-period at this institution. The study examined four patient groups, classified according to the analgesia used: No additive, levobupivacaine aloneLevobupivacaine and S (+)-ketamineLevobupivacaine and clonidineLevobupivacaine, S (+)-ketamine, and clonidinePRIMARY OUTCOME MEASURES WERE AS FOLLOWS: time to the first postoperative request for analgesia, total first 24-hour postoperative analgesia, and time to hospital discharge. RESULTS The 87 patients included had a mean ± SD age of 21.4 ± 13.5 months and weight of 11.9 ± 2.4 kg. The median doses of levobupivacaine, S (+)-ketamine, and clonidine were 0.7 mg/kg (range, 0.4-1.3), 0.5 mg/kg (0.2-1.1), and 1.8 μg/kg (0.8-2.3), respectively. The addition of S(+)-ketamine, clonidine, or both did not increase the time to first oral analgesia request. Neither did it reduce the total first 24-hour postoperative analgesia requirements or alter hospital discharge time. However, the additive drugs in combination did increase postoperative sedation. CONCLUSIONS The addition of S (+)-ketamine or clonidine to levobupivacaine 0.25% in caudal analgesia for hypospadias repair appears to be of no benefit. However, use of the additives in combination increased postoperative sedation.