Early Changes over Time in the Radiographic Assessment of Lung Edema (RALE) Score are Associated with Survival in Acute Respiratory Distress Syndrome

ABSTRACT Background The Radiographic Assessment of Lung Edema (RALE) score has been proposed to assess the severity of acute respiratory distress syndrome (ARDS) and treatments targeted at reducing pulmonary edema such as conservative fluid management cause a reduction in RALE score over time. Research question We assessed whether early changes in RALE score over time are associated with survival in patients with ARDS. Study design and methods: Data from patients enrolled in three centers in the Lung Imaging for Ventilation sEtting in ARDS (LIVE) trial with available chest radiographs at baseline (day 0) and days 2-3 were used. The RALE was scored by two independent reviewers. The primary endpoint was death by day 90, considering RALE score both at baseline and as a time-varying covariate in marginal Cox survival model. Results RALE was scored from 135, 64, and 88 radiographs on days 0, 2, and 3, respectively. Both baseline RALE (HR for each one-point increment, 1.04; 95% CI, 1.01–1.08; P = 0.006) and the change in RALE over time (HR for each one-point decrease per unit of time, 0.99; 95% CI, 0.99–0.99; P = 0.03) were associated with death by day 90, even after adjustment for age, gender, body mass index, simplified acute physiology score II, vasopressor use, and the total volume of fluids received since study entry. Interpretation The change in RALE during the first days after ARDS onset is independently associated with survival and may be useful as a surrogate endpoint in future clinical trials of new therapeutics in ARDS.