Introduction:

The use of neuromuscular blocking agents (NMBA) in adults with acute respiratory distress syndrome (ARDS) has been widely proposed. However, the efficacy and safety of this treatment is uncertain, according to the most recent literature. The objective of this study was to estimate the effect of neuromuscular blocking agents on acute respiratory distress syndrome.

Methods:

In this systematic review and meta-analysis, different databases were searched, comparing the administration of neuromuscular blocking agents versus placebo or non-treatment in patients with acute respiratory distress syndrome. Titles, abstracts and full texts of the articles were selected in duplicate by two researchers. The data for the study design, patient characteristics, interventions and results were summarized independently and in duplicate. For additional information, the authors of the selected studies were contacted by email. The GRADE guides were used to rate the quality of the evidence. We calculate the risk ratios (RR) and odds ratios (OR) with 95% confidence intervals (95% CI) for dichotomous variables, while for the continuous variables we obtained the difference in means and performed a meta-analysis of random effects. The primary outcome was the evaluation of any-cause mortality, mortality in the Intensive Care Unit, the incidence of adverse effects and the evolution of respiratory parameters.

Results:

Six randomized controlled studies (RCTs) were included. Compared to the placebo group or no treatment, neuromuscular blocking agents were associated with a significant reduction in any-cause mortality (603 [35.7%] of 1,691 patients versus 673 [40.5%] of 1,660 patients; RR 0.84 [CI 95%: 0.74-0.95] p = 0.005 I2 33%); as well as decreased mortality in the ICU (RR 0.72 [95% CI 0.57-0.91]). Compared to the placebo group or no treatment, the neuromuscular blocking agents group was associated with a significant reduction in adverse events (RR 0.72 [95% CI 0.52 to 0.99], four RCTs, 3,621 patients; p = 0.15 I2 64%) and a significant improvement in the PaO2/FiO2 ratio (11.02 mmHg [95% CI 5.38 to 16.66]; four RCTs, 3,637 patients; p = 0.0001 I2 24%).

Conclusions:

The use of neuromuscular blocking agents in adults with acute respiratory distress syndrome was associated with a significant reduction in mortality from any cause. There were fewer adverse events and a significant improvement in the PaO2/FiO2 ratio in the neuromuscular blocking agents’ group. Based on our results, we recommend the use of neuromuscular blocking agents for patients with moderate to severe ARDS who need mechanical ventilation. Due to the moderate to low quality of the evidence, new randomized studies with sufficient statistical power are required to confirm these findings.