Acute respiratory distress syndrome (ARDS) is a major cause of acute hypoxemic respiratory failure in critically ill patients and is associated with substantial mortality. Current management is largely supportive, and no pharmacologic therapy has been shown consistently to reduce mortality in a broad population of patients with ARDS. Inflammation plays a central role in the pathogenesis of ARDS. Excessive inflammatory activation contributes to alveolar-capillary injury, impaired gas exchange, and progression of organ dysfunction. Glucocorticoids may mitigate these processes and have been associated in some studies with improved clinical outcomes, including shorter duration of mechanical ventilation. However, the effect of glucocorticoids on survival remains uncertain.
ARDS is a heterogeneous syndrome with diverse etiologies, and treatment response may vary according to the underlying cause. A post hoc analysis of the Dex-ARDS trial suggested that the treatment effect of glucocorticoids may be greater in ARDS caused by pneumonia or extrapulmonary sepsis. In a cross-sectional survey of 135 patients with ARDS from 20 ICUs in China, pneumonia- and extrapulmonary sepsis-associated ARDS accounted for 77.6% of cases, indicating that these are the predominant etiologic subtypes encountered in clinical practice in China. More importantly, compared with ARDS attributable to other causes, pneumonia- and extrapulmonary sepsis-associated ARDS has been associated with higher mortality, suggesting a greater disease burden, worse prognosis, and a more urgent need for improved treatment strategies. On this basis, the present trial will enroll patients with ARDS caused by sepsis, including pneumonia and extrapulmonary sepsis.
The primary hypothesis of this study is that, among patients with sepsis-associated ARDS, dexamethasone plus usual care, as compared with placebo plus usual care, will reduce 90-day all-cause mortality. We therefore designed a multicenter, randomized, double-blind, controlled trial to evaluate the clinical efficacy of dexamethasone in patients with sepsis-associated ARDS. The primary objective is to compare dexamethasone plus usual care with placebo plus usual care with respect to 90-day all-cause mortality.