Impact of nitric oxide via cardiopulmonary bypass on pediatric heart surgery: a meta-analysis of randomized controlled trials.

Objective: The impact of nitric oxide (NO) administered via cardiopulmonary bypass (CPB) on pediatric heart surgery remains controversial. The objective of this study is to conduct a comprehensive systematic review and meta-analysis to examine the impact of NO administered via CPB on pediatric heart surgery.

Methods: This study searched 7 electronic databases to identify Randomized Controlled Trials (RCTs) on the impact of NO administration during CPB on postoperative outcomes in pediatric heart surgery. The searched databases included Embase, Medline (though PubMed), Cochrane Library, Web of Science, Wan Fang database, China National Knowledge Infrastructure (CNKI), and ClinicalTrials.gov from their inception to November 2, 2022. The included RCTs compared NO administration during CPB with standard CPB procedures or placebo gas treatment in pediatric heart surgery. fixed-effects models and/or random-effects models were used to estimate the effect size with 95% confidence interval (CI). Heterogeneity among studies was indicated by p-values and I². All analyses were performed using Review Manager software (version 5.4) in this study.

Results: A total of 6 RCTs including 1,739 children were identified in this study. The primary outcome was duration of postoperative mechanical ventilation, with the length of hospital and intensive care unit (ICU) stay as the second outcomes. Through a pooled analysis, we found that exogenous NO administered via CPB for pediatric heart surgery could not shorten the duration of postoperative mechanical ventilation when compared with the control group (standardized mean difference (SMD) -0.07, CI [-0.16, 0.02], I² = 45%, P = 0.15). Additionally, there were also no difference between the two groups in terms of length of hospital stay (mean difference (MD) -0.29, CI [-1.03, 0.46], I² = 32%, P = 0.45) and length of ICU stay (MD -0.22, CI [-0.49 to 0.05], I² = 72%, P = 0.10).

Conclusions: This meta-analysis showed that exogenous NO administration via CBP had no benefits on the duration of mechanical ventilation, the length of postoperative hospital, and ICU stay after pediatric heart surgery.