Bronchoalveolar Lavage

This chapter introduces the key technical points of bronchoalveolar lavage (BAL), as well as the application of BAL in some common pulmonary diseases. Historically, technological variation among different research institutions has led to the corresponding variation of the results of BAL. Lavage is relatively safe and can be conducted during a routine flexible bronchoscopic examination. The most common complication is post-BAL fever, a transient pyrogen effect caused by the release of biological active mediators such as cytokine presenting in 10–15% of patients. Post BAL, it has been shown that up to 90% of patients will display radiographic evidence of new or increased consolidation in the area lavaged. A minimal volume of 5mL of pooled BAL samples is needed for cellular analysis. With clear clinical and radiographic evidence, elevation of BAL eosinophils may clarify the diagnosis without need for lung biopsy.