Efficacy Of Caudal Vs Intravenous Administration Of Alpha(2) Adrenoceptor Agonists To Prolong Analgesia In Pediatric Caudal Block: A Systematic Review And Meta-Analysis

Background: alpha(2) adrenoceptor agonists have been proposed as adjuncts to prolong analgesia in pediatric caudal block. The aim of this meta-analysis was to compare the analgesic efficacy of caudal vs intravenous alpha(2) adrenoceptor agonists during pediatric caudal block.Methods: A systematic search, data extraction, bias risk assessment, and pooled data analysis were performed following the PRISMA guidelines. All randomized controlled trials comparing caudal with intravenous alpha(2) adrenoceptor agonists in pediatric caudal block were included. Relative risk and weighted mean differences (the corresponding 95% confidence intervals) were calculated for dichotomous and continuous data, respectively. Trial sequential analyses were performed to evaluate the credibility of the meta-analysis.Results: A total of 244 patients in five trials were identified. Compared with the intravenous group (9.56 +/- 4.23 hours), the time to the first rescue analgesia was prolonged in the caudal alpha(2) adrenoceptor agonists group (12.72 +/- 5.99 hours) by a weighted mean difference of 2.98 hours [95% confidence interval: 0.59-5.36 hours;P = .01]. The number of children requiring rescue analgesia in the caudal group (64, 66.67%) was lower than that in the intravenous group (80, 81.63%) [relative risk = 0.82; 95% confidence interval: 0.69-0.97;P = .02]. These findings were also verified by trial sequential analysis. There were no significant differences in the side effects.Conclusion: Caudal alpha(2) adrenoceptor agonists as adjuncts to local anesthetic during pediatric caudal block are more effective than intravenous injection. However, the results were affected by small sample size and significant heterogeneity.