An approach to the diagnosis of pulmonary infections in immunosuppressed patients.

The goal of this review is to provide an approach to the diagnosis of pulmonary infections in immunosuppressed patients. First, a framework will be provided to narrow the extensive list of possible infectious and noninfectious pulmonary complications. This can be accomplished by considering the underlying immune defect, the pattern of radiographic presentation, the rapidity of progression of radiographic infiltrates, the typical temporal pattern of infection in specific disease states, and the local epidemiology at one's institution. Next, the yields and potential complications of invasive and noninvasive diagnostic techniques for pulmonary infections are reviewed. Lastly, algorithms, which account for the pattern of radiographic presentation, the primary disease and its underlying immune defect and the anticipated yields and complications of diagnostic procedures, are provided as a suggested plan for the use of diagnostic techniques and the institution of therapy.