Plasma and BAL Cytokine Response to Corticosteroid Rescue Treatment in Late ARDS

In late ARDS, a persistent and exaggerated inflammatory response causes recurrent injury to the alveolocapillary barrier and amplification of intra-alveolar fibroproliferation. When ARDS patients fail to improve, corticosteroid (CS) rescue treatment frequently leads to rapid improvements in lung function. We tested the hypothesis that response to CS treatment is related to suppressing the inflammatory response by comparing changes in lung function to inflammatory cytokine (IC) levels in the plasma and BAL. Blood samples were obtained on days 1, 3, 5, and 7 of ARDS, and on days −5, −3, 0 (initiation of treatment), +3, +5, +7, +10, and +14 of CS treatment. Bilateral BAL was obtained on day 1 of ARDS, before administration of CS treatment, and at weekly intervals. We analyzed changes in IC levels during CS treatment in relation to improvements in lung injury score (LIS), indices of endothelial permeability, and final outcome. We also analyzed data to identify timing to a significant reduction in plasma IC levels and predictors of response. Nine patients entered the study. CS treatment was initiated 15±9 days into ARDS. Improvement in LIS (>1-point reduction) was rapid (