Efficacy of dexamethasone on postoperative analgesia in children undergoing hypospadias repair.

BACKGROUND AND OBJECTIVE: Management of post operative pain in children undergoing hypospadiasis repair, accounts for optimized surgery outcomes and improved patients' satisfaction. Thus, various studies have widely investigated the best approaches for the pain management. In this study our aim was to determine the effect of dexamethasone in combination with penile nerve block on the postoperative pain and complications in the children undergoing hypospadias surgery.

METHODS: In this randomized double-blind placebo controlled trial, after obtaining informed consent from parents or legal guardians, 42 children undergoing surgical treatment of hypospadias were randomized in two groups to receive either IV dexamethasone 0.5 mg/kg (n=23) or placebo (normal saline) (n=19) during the operation. Penile block was performed in both groups using Bupivacaine 0.5% (1mg/kg) at the end of the procedure. By the end of the operation, FLACC (Face, Leg, Activity, Cry, Consolability) pain score was assessed as the primary outcome of the study. Secondary outcomes includes timing and episodes of rescue medication consumption, post operative nausea \vomiting and bleeding. All the outcomes were assessed in the recovery room and after 2, 6, 12, and 24 hours.

RESULTS: The median of FLACC pain scores at the recovery room and 2, 6, 12, and 24 hours post operation was 2, 1, 1, 1, and 2 for the dexamethasone group and 8, 8, 7, 7, and 8 for the placebo group respectively. This were significantly different (P<0.000). The median time of first rescue medication consumption was 8 hours post operation for the dexamethasone group and three hours for the placebo group which was significantly different (z= 4.57, p<0.000). The maximum episode of post operative rescue medication consumption in dexamethasone group was 4 episodes in only one patient and the minimum was one episode in 11 patients. In comparison numbers in placebo group were five episodes in seven patients and three episodes in four patients. The result indicated that there was statistically significant difference between two groups in terms of episodes of rescue medication consumption (Chi2= 31.4, p<0.000).

CONCLUSION: Single dose of intravenous dexamethasone (0.5 mg/kg) in combination with penile block decreased the post operative pain measures, and total post operative analgesic requirement. It also increased the onset of the first analgesic requirement compared to penile block alone.