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: 1. No additive, levobupivacaine alone. 2. Levobupivacaine and S (+)-ketamine. 3. Levobupivacaine and clonidine. 4. Levobupivacaine, S (+)-ketamine, and clonidine. Primary 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.