Bronchoalveolar lavage

Bronchoalveolar lavage (BAL), also known as bronchoalveolar washing, is a diagnostic method of the lower respiratory system in which a <a href="/facts/Bronchoscope/n1WHpAbP">bronchoscope</a> is passed through the mouth or nose into an appropriate airway in the <a href="/facts/Lung/gTWXI6Fj">lungs</a>, with a measured amount of fluid introduced and then collected for examination. This method is typically performed to <a href="/facts/Medical_diagnosis/J47rvb0p">diagnose</a> pathogenic <a href="/facts/Infection/182XrncP">infections</a> of the lower respiratory airways (e.g. <a href="/facts/Pneumonia/Jw0KquTA">pneumonia</a> and <a href="/facts/COVID-19/YsUgvsaX">COVID-19</a>), though it also has been shown to have utility in diagnosing <a href="/facts/Interstitial_lung_disease/0LQEwsGc">interstitial lung disease</a>. Bronchoalveolar <a href="/facts/Lavage/42u4PNqL">lavage</a> can be a more sensitive method of detection than nasal swabs in respiratory molecular diagnostics, as has been the case with SARS-CoV-2 where bronchoalveolar lavage samples detect copies of viral RNA after negative nasal swab testing.
In particular, bronchoalveolar lavage is commonly used to diagnose infections in people with <a href="/facts/Immunocompromised/CIEujXmc">immune system problems</a>, <a href="/facts/Ventilator-associated_pneumonia/LvzHBPsE">pneumonia</a> in people on <a href="/facts/Mechanical_ventilation/XSQ84JX9">ventilators</a>, and <a href="/facts/Acute_respiratory_distress_syndrome/1V3mxJkU">acute respiratory distress syndrome</a> (ARDS). It is the most common method used to sample the <a href="/facts/Epithelial_lining_fluid/gsvl9IJL">epithelial lining fluid</a> (ELF) and to determine the protein composition of the pulmonary airways.
BAL has even been used therapeutically to remove mucus (<a href="/facts/Sputum/gduT4NG3">sputum</a>), improve airway ventilation, and reduce airway inflammation in conditions such as <a href="/facts/Chronic_obstructive_pulmonary_disease/ud3oXGCr">chronic obstructive pulmonary disease</a> (COPD) and pediatric <a href="/facts/Mycoplasma_pneumonia/pUQ1uKCk">Mycoplasma pneumonia</a>. A much more intense version involving up to 50 liters of fluid is called <a href="/facts/Whole_lung_lavage/kRQ9hYPq">whole lung lavage</a> (WLL) and is used to treat <a href="/facts/Pulmonary_alveolar_proteinosis/VzVGRMmC">pulmonary alveolar proteinosis</a> (PAP). When conditions disallow WLL, an endoscopic BAL can be used as a bridging procedure.

Bronchoalveolar lavage open-in-new

Bronchoalveolar lavage