______ (BAL/TBA) is gold standard for culture and lower airway dz.

• A. BAL
• B. TBA
• C. Endoscopy
• D. Radiography

Answer: (B)

Bronchoalveolar lavage is the approach that provides a representative sample from the lower airways for both culture and cytology. By using bronchoscopy to instill sterile saline into a distal airway and then retrieve it, you obtain material from the alveolar and lower bronchial spaces, which allows accurate identification of pathogens and assessment of inflammatory cell patterns. Sampling from the trachea and larger bronchi (tracheobronchial aspirate) Can be contaminated by upper airway flora and may not reflect lower airway disease as reliably. Endoscopy mainly visualizes airways and may guide sampling but does not by itself yield a superior lower airway culture sample. Radiography reveals structural changes but does not provide culture or cytology. Therefore, bronchoalveolar lavage is the gold standard for culture and lower airway disease.