Comparison of Continuous Neuromuscular Blocking Agent Titration Strategies in Acute Respiratory Distress Syndrome

Background: Neuromuscular blocking agents (NMBAs) are suggested as an option in moderate to severe acute respiratory distress syndrome (ARDS) to improve ventilator synchrony (VS) and overall oxygenation. However, NMBA titration strategies have not been adequately compared. Objective: The purpose of this study was to compare the oxygenation change in ARDS patients that received continuous NMBAs titrated to nonprotocolized VS versus train of four (TOF). Methods: This multicenter, propensity matched, retrospective cohort study assessed patients with ARDS on an NMBA infusion for 24 hours. The primary endpoint was the percent change in PaO 2 :FiO 2 at 24 hours. Results: A total of 191 patients were included in this propensity score matched analysis (VS = 72; TOF = 119). The study cohort was mostly composed of severe ARDS (VS = 63.9%; TOF = 58.0%) and managed on cisatracurium (VS = 100.0%; TOF = 87.4%). Ventilator synchrony titration patients implemented more prone positioning (VS = 65.3%; TOF = 41.2%; P = 0.002) but had fewer plateau pressures maintained at < 30 cm H 2 O (VS = 50.0%; TOF = 73.1%; P = 0.002). The percentage change in PaO 2 :FiO 2 at 24 hours was +23.5% in the VS group and +23.2% in the TOF group ( P = 0.459). There were no significant differences found in the percentage change in PaO 2 :FiO 2 at 12 hours or 48 hours, cumulative cisatracurium dose, duration of mechanical ventilation, or hospital or intensive care unit length of stay. 28-day mortality occurred in 61.1% of the VS group and 43.7% of the TOF group ( P = 0.029). Conclusion and Relevance: In ARDS patients on continuous NMBAs, TOF titration had similar improvement in PaO 2 :FiO 2 ratio at 24 hours and was associated with reduced 28-day mortality, as compared with nonprotocolized VS titration. Prospective studies are warranted to validate and further investigate optimal NMBA titration strategies.