This study aims to compare the diagnostic yield of bronchoalveolar lavage (BAL) using a thick conventional bronchoscope and bronchial washing (BW) using a thin bronchoscope in the diagnosis of pulmonary tuberculosis.

In patients with suspected pulmonary tuberculosis (TB), confirm the presence of TB bacilli through sputum testing is essential for diagnosis. However, the sensitivity of sputum specimens is suboptimal, and some patients may be unable to produce sputum. In such situations, it is traditionally known that obtaining samples through bronchoscopy increases the diagnostic yield of pulmonary TB. Typically, the method of using a thick, conventional bronchoscope to perform bronchial washing (BW) or bronchoalveolar lavage (BAL) is commonly employed. However, a drawback of the conventional bronchoscope is its inability to reach close to peripheral pulmonary TB lesions due to its larger diameter.

Recent studies have reported an increased diagnostic yield for pulmonary TB when using a thin bronchoscope for BW compared to using a thick, conventional bronchoscope for BW. However, a direct comparison with the method of performing BAL (BAL may have a higher diagnostic yield compared to BW) using a conventional bronchoscope has not been conducted. This study aims to prospectively compare the diagnostic yield for pulmonary TB between BAL using a conventional bronchoscope and BW using a thin bronchoscope.

Inclusion Criteria:

• participants age > 17 years with suspected pulmonary TB
• possible active pulmonary TB evident on chest radiography or CT scan
• negative AFB smear results (using two consecutive self-expectorated sputum)
• negative TB-PCR results (using one self-expectorated sputum)
• inability to produce self-expectorated sputum

Exclusion Criteria:

• a request for empirical TB treatment rather than bronchoscopy
• suspect pulmonary TB lesions that are difficult to target for BAL or BW (e.g., multiple discrete tiny nodules)
• contra-indication of bronchoscopy (e.g., bleeding tendency, hypoxemia requiring oxygen, or uncontrolled cardio/cerebrovascular disease)