Acute respiratory distress syndrome mimics: the role of lung biopsy

PURPOSE OF REVIEW: Acute respiratory distress syndrome (ARDS) mimics is a condition looking like ARDS but that does not fulfill every criterion according to the recent Berlin definition. The purpose of this review is to better delineate ARDS mimics, to discuss why the complete diagnosis of ARDS is important, and to make a brief overview on the role of open lung biopsy in this setting. RECENT FINDINGS: Recent autopsy and lung biopsy data from ARDS patients compared lung histologic findings with the new Berlin definition of ARDS. Among them, there are some limited data about two niches, namely open lung biopsy and ARDS mimics suggesting that lung histology is important for making the diagnosis and offering the accurate management. This includes specific new treatments or stopping some medications toxic to the lung. Finally, ARDS with diffuse alveolar damage could be a specific subphenotype of ARDS with poor prognosis. SUMMARY: An ARDS mimic enhances the need of making ARDS diagnosis as comprehensive as possible. In some limited cases, open lung biopsy in skilled hands may have implications for management.