Addition of clonidine and fentanyl: comparison between three different regional anesthetic techniques in circumcision

Abstract

Background: Several techniques have been used for alleviating post-circumcision pain with regional anesthetics being more effective than systemic opioids. Our aim was to compare the effectiveness of dorsal penile block, ring block (RB) and dorsal penile block associated with RB in reducing post-circumcision pain in children.

Methods: We conducted a prospective randomized double-blind clinical trial on 100 boys aged between 1 month and 5 years undergoing elective circumcision. Each 20 ml of local anesthetic mixture contained 9 ml lidocaine 1% without epinephrine, 9 ml bupivacaine 0.5%, 1 ml fentanyl (50 microg.ml(-1)) and 1 ml clonidine (75 microg.ml(-1)). They were allocated to one of three groups: 33 boys were given a RB with 1-1.5 ml (group 1), 32 had a dorsal penile block with 1.5-4 ml (group 2) and 35 had a combined ring and dorsal penile block with 2.5-5 ml of anesthetic mixture based on the child's age.

Results: Ninety-one children (91%) completed the clinical trial (three failed blocks and six follow-up losses). The groups were similar with regard to age, weight, height, duration of surgery and hemodynamic status. The average pain scores were significantly higher with a RB compared with the other two groups (P < 0.05) for the first postoperative day. RB children and dorsal penile block children consumed significantly more analgesics for the first six postoperative hours (P < 0.05). The surgeon's satisfaction was significantly higher with the ring + dorsal penile block group (100%) compared with the other two groups (P = 0.032).

Conclusion: Dorsal penile block plus RB technique is superior to dorsal penile block alone and RB alone in reducing postcircumcision pain in children.