Diagnostic accuracy of bronchial washings in smear negative pulmonary tuberculosis

Background: diagnostic modalities for sputum smear negative pulmonary tuberculosis are multiple with different accuracies. bronchial washing may help reduce the non-indicated use of anti-tuberculosis treatment. aim: to determine the diagnostic accuracy of bronchial washing for afb in smear negative pulmonary tuberculosis (ptb) taking sputum culture as gold standard. methods: this cross-sectional survey conducted at department of medicine,sharif medical & dental college lahore. one hundred and eighty patients with suspected smear negative pulmonary tuberculosis were enrolled in the study. all patients underwent bronchoscopy procedure according to standard protocol so their bronchial washings were sent for smear examination immediately. results of both post bronchoscopy sputum culture and bronchial washings were recorded. diagnostic accuracy of bronchial washing was calculated. results: the mean age of 35.34±9.14 ranged from 23 to 56 years. where 105 patients (58.3%) were male and 75 patients (41.7%) were female in our study,sensitivity of bronchial washing came out 62%,specificity 31%,positive predictive value 72%,negative predictive value 23%,taking culture as gold standard in patients with tuberculous. there was no effect of gender and age on diagnostic accuracy. conclusion: it is concluded that bronchial washing can be used as a proxy indicator of tuberculosis in patients with sputum smear negative pulmonary tuberculosis till we may wait for results of culture as it has shown high sensitivity.