Evaluation of Early versus Late Neuromuscular Blockade in Acute Respiratory Failure

Introduction: In 2010, a multicenter, double-blind trial (ACURASYS) demonstrated an improved adjusted 90-day survival with administration of neuromuscular blocking agents (NMBAs) early in the course of severe acute respiratory distress syndrome. To date, this is the only pharmacologic agent tested in a large multicenter clinical trial that has been shown to improve survival.

Objectives: We sought to determine if there was a difference in 28-day ventilator-free days in patients with acute respiratory failure (ARF) receiving early administration of NMBAs compared to late administration of NMBAs.

Study Design: A multicenter, retrospective cohort study conducted between March 2011 and July 2015.

Methods: Adult patients admitted to an intensive care unit who received a continuous infusion of a NMBA for more than 24 hours for ARF (SpO2/FiO2 ratio or PaO2/FiO2 ratio <315 mmHg or <300 mmHg, respectively) were included. Twenty-eight day ventilator-free days, length of stay, mortality, organ failure, and complications from paralysis and mechanical ventilation were compared in patients who received early NMBA administration (≤48 hours from ARF diagnosis) versus late administration (>48 hours). Data are reported using descriptive statistics, Mann-Whitney Rank Sum test, and chi-square test as appropriate.

Results: To date, 274 patients have been included (mean age 53.4±15.5 years, males 62.7%) with 217 receiving early NMBA administration and 57 receiving late administration. Patients receiving early administration of NMBAs had more 28-day ventilator-free days (median [range]: 7.5 [0,19.4] vs 0 [0,3.0] days, p<0.001), shorter hospital length of stay (median [range]: 18 [8,36] vs 33 [18.25,53.5] days, p<0.001), and similar 28-day mortality (31.3 vs 38.6%, p=0.30) compared to patients receiving late administration. Differences in organ failure and complications are yet to be determined.

Conclusions: : The preliminary results appear to show that patients receiving early administration of NMBAs for ARF may have better outcomes compared to those who received late administration.