Bronchoalveolar lavage

Bronchoalveolar lavage (BAL), also known as bronchoalveolar washing, is a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination. It is typically performed to diagnose lung disease. Bronchoalveolar lavage (BAL), also known as bronchoalveolar washing, is a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination. It is typically performed to diagnose lung disease. In particular, bronchoalveolar lavage is commonly used to diagnose infections in people with immune system problems, pneumonia in people on ventilators, some types of lung cancer, and scarring of the lung (interstitial lung disease). It is the most common method used to sample the epithelial lining fluid (ELF) and to determine the protein composition of the pulmonary airways. It is often used in immunological research as a means of sampling cells (for example, T cells) or pathogen levels (for example, influenza virus) in the lung. BAL has been used for therapeutic applications. Whole lung lavage (WLL; informally, 'lung washing') is a treatment for pulmonary alveolar proteinosis.