Sputum induction in the diagnosis of pulmonary tuberculosis in patients without sputum

Sputum induction has been recently introduced as an effective and inexpensive method for obtaining high quality sputum samples in patients without spontaneous sputum. As all Iranian physicians might not be familiar with this method yet, the results of this study could be of help in this regard. During June 2010 to January 2011, all pulmonary tuberculosis (PTB) suspected patients, with clinical and/or radiological evidence in favor of PTB who had been referred to the Pulmonary Diseases department of Imam Khomeini Medical Center were enrolled in the study, if they were without spontaneous sputum. Sputum induction was performed using ultrasound nebulized hypertonic 3% sterile saline for 20 minutes. The laboratory was requested to report if the samples were of the intended quality (Polymorphonuclear Cells/Squamus Epithelial Cells≥2). The patients’ demographic data, HIV serology and chest radiological findings in favor of PTB were recorded and analyzed. In 50 patients with suspected PTB [23 men (mean age (±SD), 51.21±20.24) and 27 women (mean age (±SD) 55.40±18.00)], cough was the most common complaint. The most prevalent radiological findings were infiltration and consolidation. PPD was positive in 21 (42%) patients. Sputum induction led to obtaining proper sputum samples in 90% of the patients. Positive sputum smear and culture were seen in 13 (26%) cases. Sputum induction is a cost-effective and minimally invasive method which is associated with satisfactory results for obtaining high quality sputum samples in patients without spontaneous sputum.