Background While specific interventions have previously demonstrated benefit in patients with the Acute Respiratory Distress Syndrome (ARDS), use of these interventions is inconsistent, and patient mortality remains high. The impact of variability in center management practices on ARDS mortality rates remains unknown. Research Question What is the impact of treatment variability on mortality in patients with moderate-to-severe ARDS in the United States (US)? Study Design and Methods We conducted a multicenter, observational cohort study of mechanically ventilated adults with ARDS and PaO2/FiO2 < 150 on positive end expiratory pressure (PEEP) > 5 cm H2O, who were admitted to 29 US centers between October 1, 2016 and April 30, 2017. The primary outcome was 28-day in-hospital mortality. Center variation in ventilator management, adjunctive therapy use, and mortality were also assessed. Results A total of 2,466 patients were enrolled. Median baseline PaO2/FiO2 was 105 (IQR 78.0, 129.0). In-hospital 28-day mortality was 40.7%. Initial adherence to lung protective ventilation (tidal volume < 6.5 ml/kg predicted body weight, plateau pressure and/or peak inspiratory pressure < 30mm H2O) was 31.4% and varied between centers (0%-65%), as did rates of adjunctive therapy use (27.1%-96.4%), types of modalities used (neuromuscular blockade, prone positioning, systemic steroids, pulmonary vasodilators, and extracorporeal support), and mortality (16.7-73.3%). Center standardized mortality ratios (SMRs), calculated using baseline patient-level characteristics to derive expected mortality rate, ranged from 0.33 to 1.98. Of the treatment-level factors explored, only center adherence to early lung protective ventilation (LPV) was correlated with SMR. Interpretation Substantial center-to-center variability exists in ARDS management, suggesting that further opportunities for improving ARDS outcomes exist. Early adherence to LPV was associated with lower center mortality and may be a surrogate for overall quality of care processes. Future collaboration is needed to identify additional treatment-level factors influencing center-level outcomes. Clinical Trial Registration ClinicalTrials.gov Identifier: NCT03021824
Variation in Early Management Practices in Moderate-to-Severe Acute Respiratory Distress Syndrome in the United States