To Block or Not: Updates in Neuromuscular Blockade in Acute Respiratory Distress Syndrome.

Objective: To review and evaluate neuromuscular blocking agents (NMBAs) in critically ill patients with acute respiratory distress syndrome (ARDS). Data Sources: A literature search utilizing PubMed was performed (January 1991 to January 2020) using the following search terms: (neuromuscular blocking agents OR neuromuscular blockade OR cisatracurium OR rocuronium OR vecuronium OR pancuronium OR atracurium) AND *acute respiratory distress syndrome OR acute lung injury). Publications in English were evaluated. Study Selection and Data Extraction: Relevant clinical studies in humans were considered. Data Synthesis: Although NMBAs have been used for decades in the setting of ARDS, questions regarding mortality benefit remain. Early NMBA, within 48 hours of lung injury, have been historically used in critically ill patients with ARDS to aid in increasing alveolar recruitment, improving patient-ventilator synchrony, and promoting oxygenation by the prevention of contraction of respiratory muscles. Until recently, the literature showed an improvement in 90-day adjusted mortality. However, recent literature has demonstrated the lack of a mortality benefit. The continued receipt of NMBAs, with no clear benefit, could potentially lead to increased costs, skin breakdown, corneal abrasions, venous thromboembolisms, intensive care unit acquired weakness, and awareness with inappropriate sedation. Relevance to Patient Care and Clinical Practice: This review aims at discussing the preferred NMBA based on mechanism of action and reviews specific clinical trial data for the use of NMBAs in ARDS, clinical implications of these trial data, complications for the use of NMBAs, and needed future directions. Conclusions: The mortality benefit of NMBAs in ARDS has contradicting evidence with potentially serious adverse effects and notable controversies.