Survival predictor in patients with acute respiratory distress syndrome and diffuse alveolar damage undergoing open lung biopsy

Background: Diffuse alveolar damage (DAD) is a typical pathological finding of open lung biopsies in patients with acute respiratory distress syndrome (ARDS). Patients with ARDS and DAD have been reported to have a poorer prognosis than those without DAD. The aim of this study was to investigate the survival predictors in patients with ARDS and DAD. Methods: We retrospectively reviewed all ARDS patients who underwent an open lung biopsy which showed evidence of DAD from January 2006 to June 2015 at Chang Gung Memorial Hospital. Clinical data including baseline characteristics, medication, and survival outcomes were analyzed. Results: A total of 64 ARDS patients with DAD were eligible for analysis and divided into known etiology (n = 17, 26.6%) and unknown etiology groups (n = 47, 73.4%). There was no significant difference in hospital mortality rate between the two groups (71.9% vs. 70.6%, p = 0.890). Univariate logistic regression analysis revealed that sequential organ failure assessment (SOFA) score at the time of a diagnosis of ARDS, and SOFA score, PaO₂/FiO₂ ratio, and positive end expiratory pressure level when the biopsy was performed were associated with hospital mortality. Multivariate analysis showed that the SOFA score on the day of the biopsy was an independent predictor of hospital mortality (odds ratio 1.413, 95% confidence interval 1.127–1.772; p = 0.03). There were no significant differences in the use, dose, duration and timing from ARDS to glucocorticoid therapy between the survivors and nonsurvivors. Conclusion: For selected ARDS patients who underwent an open lung biopsy with pathological DAD, SOFA score was an independent predictor of hospital mortality.