The analgesic effect of clonidine as an adjuvant in dorsal penile nerve block

INTRODUCTION Dorsal penile nerve block (DPNB) is a commonly performed regional anesthetic technique for male circumcision. The aim of this study was to assess the analgesic effect of the adjunction of clonidine to bupivacaine 0.5% in this block. METHODS It was a prospective randomized double-blind clinical trial including 40 ASA1 boys aged from 1 to 4 years undergoing elective circumcision. Dorsal penile nerve block was performed under general Anesthesia. Patients were randomized in two groups: Group 1 (G1): received 0.1 ml/Kg of bupivacaine 0.5% with 1µg/kg of clonidine in each side. Group 2 (G2): received 0.1 ml/kg of bupivacaine 0.5% with placebo in each side. The failure of the DNPB was defined by the increase of heart rate by more than 25% comparing to baseline and in his case an intravenous injection of 20 µg/kg of alfentanyl was given. Post-operative pain was assessed by CHEOPS score. RESULTS A total of 40 patients were enrolled. Demographic parameters were similar in both groups. We noted no case of DNPB failure in this study. The supply for additional analgesia was seen in 12 patients in group 2 versus 3 cases in group 1. CHEOPS (Children's Hospital of Eastern Ontario Pain Scale) was significantly lower in group 1 from 2nd post operative hour until the 24th hour. CONCLUSION Clonidine can be used in dorsal penile nerve block to improve and to prolong its analgesic effects after male circumcision.