Novel method for sputum induction using the Lung Flute in patients with suspected pulmonary tuberculosis.

BACKGROUND AND

OBJECTIVE

The Lung Flute is a small self-powered audio device that generates sound waves, which vibrate in tracheobronchial secretions. This was a preliminary trial to evaluate the usefulness of the Lung Flute for sputum sampling in patients suspected of pulmonary tuberculosis (TB).

METHODS

Thirty-four patients who were not expectorating sputum, but for whom sputum examination was required for the differential diagnosis of TB or other diseases, were enrolled in the study. Patients were instructed to blow out fast and hard through the Lung Flute and to repeat this for a total 20 sets of two blows each.

RESULTS

Using the Lung Flute, sputum samples were collected within 10 or 20 min from 30 of 34 patients (88%). The device permitted a rapid diagnosis of TB in seven of 15 confirmed TB cases. In three patients acid-fast bacillus smears were positive. In four patients acid-fast bacillus smears were negative, but PCR tests for TB were positive. Hyperventilation-related symptoms occurred in three patients.

CONCLUSIONS

The application of the Lung Flute may represent a promising technique for the rapid diagnosis of pulmonary TB.