The Efficacy of Neuromuscular Blocking Agents in ARDS

In patients undergoing mechanical ventilation for the acute respiratory distress syn- drome (ARDS), neuromuscular blocking agents may improve oxygenation and de- crease ventilator-induced lung injury but may also cause muscle weakness. We evalu- ated clinical outcomes after 2 days of therapy with neuromuscular blocking agents in patients with early, severe ARDS. Materials and Methods: In this multicenter, double-blind trial, 340 patients presenting to the intensive care unit (ICU) with an onset of severe ARDS within the previous 48 hours were ran- domly assigned to receive, for 48 hours, either cisatracurium besylate (178 patients) or placebo (162 patients). Severe ARDS was defined as a ratio of the partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FiO2) of less than 150, with a positive end-expiratory pressure of 5 cm or more of water and a tidal volume of 6 to 8 ml per kilogram of predicted body weight. Results: The hazard ratio for death at 90 days in the cisatracurium group, as compared with the placebo group, was 0.68 (95% confidence interval [CI], 0.48 to 0.98; P= 0.04), after adjustment for both the baseline PaO2:FIO2 and plateau pressure and the Simplified Acute Physiology II score. Conclusions: In patients with severe ARDS, early administration of a neuromuscular blocking agent improved the adjusted 90-day survival and increased the time off the ventilator without increasing muscle weakness.