Longer than expected-duration of caudal analgesia with two different doses of levobupivacaine in children undergoing hypospadias repair.

OBJECTIVE: To assess our study design and to obtain preliminary data for a dose-effect study on levobupivacaine for caudal analgesia in patients undergoing hypospadias repair. STUDY DESIGN: non randomised, non-blinded pilot study. METHOD: For this non-randomized, non-blinded pilot study, 20 patients (median age 17 months, median weight 10.5 kg) were allocated to two groups receiving either 0.5 mL kg(-1) levobupivacaine 0.125% (Group 0) or 0.5 mL kg(-1) levobupivacaine 0.375% (Group 1) caudally after induction of anaesthesia for pain control. No further analgesia was given before, during or after the procedure. Pain scores (Children's and Infants' Postoperative Pain Scale) were recorded throughout the observation period, which lasted from the start of the procedure until hospital discharge on the following day. RESULTS: Group 0: six out of 10 patients remained pain free throughout the observation period. Group 1: six out of seven patients remained pain free throughout the observation period. CONCLUSION: Both concentrations of levobupivacaine provided excellent analgesia throughout surgery. The postoperative analgesia with both doses of levobupivacaine was found to be significantly longer lasting than previously reported. The study design, with a tight and extensive observation scheme, proved to be feasible, but given the surprisingly long-lasting analgesia, the observation period needs to be extended in future studies