Neuromuscular blocking agents for acute respiratory distress syndrome: an updated meta-analysis of randomized controlled trials

Backgrounds: The aim of this study is investigating the benefits and harms of neuromuscular blocking agents (NMBAs) in patients with acute respiratory distress syndrome (ARDS). Methods: We comprehensively searched PubMed, EMBASE, and Cochrane library for randomized controlled trials comparing NMBAs to any other comparator. We pooled data using relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, with 95% confidence intervals. We assessed the quality of included studies using the Cochrane tool and levels of evidence using the GRADE method. Results: Finally, six RCTs (n = 1557 patients) were eligible for analysis. The results showed NMBAs use was not associated with reduced 28 days mortality (RR 0.78; 95% CI, 0.58 to 1.06; P = 0.11), 90 days mortality (RR, 0.92; 95% CI, 0.81 to 1.04; P = 0.16), and intensive care unit (ICU) mortality (RR, 0.90; 95% CI, 0.79 to 1.03; P = 0.13) in patients with ARDS. However, 21-28 days mortality was slightly lower in patients received NMBAs (RR 0.73; 95% CI, 0.54 to 0.99; P = 0.04; I-2 = 53%). Besides, NMBAs use could improve the PaO2/FiO(2) ratio at 48 and 72 h, decrease plateau pressure and PEEP at 72 h. Additionally, NMBAs had no significant effects on days free of ventilation at day 28 (WMD, 0.55; 95% CI, -0.46 to 1.57; P = 0.29), days not in ICU at day 28 (WMD, 0.12; 95% CI, -0.85 to 1.08; P = 0.82), ICU-acquired weakness (RR, 1.23; 95% CI, 0.99 to 1.93; P = 0.06). Finally, NMBAs use was associated with a lower risk of barotrauma (RR, 0.55; 95% CI, 0.35 to 0.85; P = 0.007). Conclusion: In patients with respiratory distress syndrome, NMBAs may be beneficial in reverse refractory hypoxemia and may be associated with reduced short-term mortality and incidence of barotrauma. However, there is no significant effects of NMBAs on mid-term and long-term mortality, and further studies are required.