Bronchoalveolar lavage: clinical role and quantitative assessment.

The field of research bronchoalveolar lavage has grown exponentially in the past decade. Despite this growth, the clinical role of lavage is uncertain. The authors review the clinical areas in which lavage has made its greatest impact as a diagnostic test (e.g. eosinophilic pneumonia, eosinophilic granuloma, alveolar proteinosis, infection, and neoplasia). The importance of the test early in the evaluation of undiagnosed diffuse alveolar diseases is considered. Finally we discuss the possibility that urea marks the recovered lining fluid volume and thus serves as a standard denominator. Results from our laboratory indicate that it does not. We feel that lavage is clinically useful and should be employed in the evaluation of undiagnosed diseases. Although it has provided data about the pathogenesis of chronic inflammatory diseases, its role in the longitudinal evaluation of these illnesses remains to be proven.