Invasive diagnostic strategies in immunosuppressed patients with acute respiratory distress syndrome.

Immunosuppression predisposes the host to development of pulmonary infections, which can lead to respiratory failure and the development of acute respiratory distress syndrome (ARDS). There are multiple mechanisms by which a host can be immunosuppressed and each is associated with specific infectious pathogens. Early invasive diagnostic modalities such as fiber-optic bronchoscopy with bronchoalveolar lavage, transbronchial biopsy, and open lung biopsy are complementary to serologic and noninvasive studies and assist in rapidly establishing an accurate diagnosis, which allows initiation of appropriate therapy and may improve outcomes with relative safety.