Since this study was not prospective in nature, we cannot be sure that all patients with TB were identified in our survey. However, our institution is the sole source of care for most of the patients studied. All 99 patients with documented M tuberculosis were identified and for those 50 patients who underwent bronchoscopy, the bronchoscopy specimen yielded a diagnosis in more than 90 percent. Although empiric antituberculosis drugs were used in some patients who underwent bronchoscopy, antifungal agents were not employed for prolonged empiric trials.
In order to provide a rapid diagnosis, several techniques have been proposed. These include a radiometric method, which is sensitive but not specific for M tuberculosis. Measurements of antigens and antibodies to M tuberculosis also have been used, but are not specific enough for general use. Recently, an assay for tuberculostearic acid has proved very sensitive and specific. buy ventolin inhalers
An argument has been made that bronchoscopy is done too frequently in patients who are smear-negative but likely to have TB. One expert recommends “most patients should not have bronchoscopy until sputum culture results are available.” At our institution, patients with smear-negative TB are still unlikely to have a positive culture. We found a significantly higher yield for bronchoscopy, both smear and culture, than for the sputum culture alone.