Intraoperative cryoanalgesia on reducing post-tonsillectomy pain scales: a meta-analysis of randomized controlled trials

To assess the effect of intraoperative cryoanalgesia on subjective pain scores of patients after tonsillectomy.

A systematic review of PubMED, Web of Science, EMBASE was performed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) standards. For the first time, we included and quantitative synthesized English-language randomized controlled trials (RCT) evaluating patients of all age groups with benign pathology who underwent tonsillectomy with intraoperative cryoanalgesia versus without.

A total of 835 publications were identified, and 7 articles with 463 participants met our criteria were selected for meta-analysis. The standard mean difference for overall subjective pain score, subjective pain scores at postoperation Day1 (POD1), POD7 were −1.44 with 95% confidence interval (CI) [−2.17, −0.72], P = .0001; −1.20 with 95% CI [−1.89, −0.50], P = .0007; −0.90 with 95% CI [−1.46, −0.35], P = .001 respectively, both in favor of cryoanalgesia. Nevertheless, subgroup analysis by surgical technique showed no robust effect between hot technique and “relative” hot technique on overall pain: (−1.72, 95% CI [−2.71, −0.73]) vs. (−1.06, 95% CI [−2.20, 0.07]), p=.39; on POD1: (−1.56, 95% CI [−2.78, −0.33]) vs. (−0.97, 95% CI [−1.83, −0.11]), p=.39; and on POD7 (−1.11, 95% CI [−1.81, −0.40]) vs. (−0.89, 95% CI [−2.02, 0.25]), p=.13. The standard mean difference for postoperative secondary bleeding rate was 1.29 with 95% CI 0.37,4.52], p = .06, no difference in 2 groups.

Limited evidence suggests that intraoperative cryoanalgesia during tonsillectomy leads to lower subjective pain score on overall, POD1 and POD7 without differences on post-operation bleeding rate.