Brief Discussion of Bronchoalveolar Lavage (BAL) Fluid

Bronchoalveolar lavage (BAL) fluid is a respiratory sample obtained during bronchoscopy by instilling sterile saline into a segment of the lung and then recollecting it. It represents material from the lower respiratory tract, including alveoli and bronchioles.

BAL fluid examination is used in the diagnosis of lung infections, interstitial lung diseases, malignancies, and inflammatory conditions. It is especially valuable for detecting tuberculosis, fungal infections, opportunistic infections, and malignant cells in suspected lung cancer.

Laboratory analysis includes cytology, microbiology, and immunological studies. Although minimally invasive, BAL provides important diagnostic information when sputum examination is inconclusive.