Role of bronchoalveolar lavage in the management of immunocompromised patients with pulmonary infiltrates

Pulmonary infiltrates are a significant cause of morbidity and mortality in immunocompromised patients and remain a diagnostic challenge due to the broad range of etiologies that include infection and malignancy. Empiric therapy may be sub-optimal and can adversely impact outcome. Therefore, a confirmed diagnosis is necessary and flexible bronchoscopy with bronchoalveolar lavage (BAL) may be a useful diagnostic tool. Samples are obtained for microbiological and cytological testing, but the procedure carries risk of complications including the adverse events related to moderate sedation. A review of published literature on BAL in immunocompromised patients from the year 2000 was undertaken focusing on diagnostic yield, complication rate, mortality as well as factors impacting these outcomes. Studies in which the majority of patients were supported on mechanical ventilation were excluded. A total of 23 studies (7 prospective and 16 retrospective) met inclusion criteria. This covered 3,395 procedures in 3,192 patients with a mean age of 47.4 years; 60.3% male gender. Diagnostic yield ranged from 26% to 69% with no clear association between diagnostic yield and etiology of immunosuppression or clinical/radiological presentation. Post BAL modification of treatment as an indicator for clinical utility ranged from 11% to 84%; and complication rate ranged from 1% to 52%. No specific factors were associated with increased adverse event rate. This review provides a summary of the data on the use of BAL for diagnosis of pulmonary infiltrates in immunocompromised patients, highlighting the heterogeneity of patients, significant variation in findings reported and the need for more data to optimize patient selection.