The comparison of ketamine with tramadol for postoperative pain relief on children following adenotonsillectomy or tonsillectomy A meta-analysis of randomized controlled trials

Introduction: The comparison of ketamine with tramadol for pain control remains controversial in pediatric adenotonsillectomy or tonsillectomy. We conduct a systematic review and meta-analysis to explore the efficacy of ketamine vs tramadol for pain relief in children following adenotonsillectomy or tonsillectomy. Methods: We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through October 2019 for randomized controlled trials (RCTs) assessing the effect of ketamine vs tramadol for pediatric adenotonsillectomy or tonsillectomy. This meta-analysis is performed using the random-effects model. Results: Six RCTs are included in the meta-analysis. Overall, compared to ketamine group for pediatric adenotonsillectomy or tonsillectomy, tramadol is associated with substantially lower CHEOPS at 1 h (SMD = 1.56; 95% CI = 0.20-2.92; P = .02; low quality) and longer first time of additional pain medication (SMD = -0.47; 95% CI = -0.74 to -0.19; P = .0008; low quality), but demonstrates no obvious effect on CHEOPS at 6 h (SMD = 0.51; 95% CI = -1.17 to 2.19; P = .55; low quality), sedation scale at 1 h (SMD = -0.80; 95% CI = -3.07 to 1.48; P = .49; low quality) or additional pain medication (RR = 1.31; 95% CI = 0.85-2.02; P = .23; moderate quality). Conclusions: Tramadol may be better to alleviate the postoperative pain after pediatric adenotonsillectomy or tonsillectomy.