Performance of CBNAAT on Pleural Biopsies Obtained by Semirigid Thoracoscopy for Diagnosis of Unexplained Pleural Effusion: A Prospective Study from North India.

BACKGROUND: Exudative pleural effusions are commonly encountered in clinical practice, but in about one-fourth of cases, etiology remains elusive after initial evaluation. Medical thoracoscopy with semirigid thoracoscope is a minimally invasive procedure with high diagnostic yield for diagnosing pleural diseases, especially these undiagnosed exudative pleural effusions. In tubercular endemic areas, often, these effusions turn out to be tubercular, but the diagnosis of tubercular pleural effusion is quite challenging due to the paucibacillary nature of the disease. Although culture is the gold standard, it is time-consuming. Cartridge-based nucleic acid amplification test (CBNAAT) is a novel rapid diagnostic test for tuberculosis (TB) and has been recommended as the initial diagnostic test in patients suspected of having extrapulmonary TB (EPTB). MATERIALS AND METHODS: We conducted a prospective observational study of 50 patients with undiagnosed pleural effusion admitted to our tertiary care hospital. The primary aim of the study is to evaluate the diagnostic performance of CBNAAT on thoracoscopic guided pleural biopsy and compare it with conventional diagnostic techniques like histopathology and conventional culture. RESULTS: Of 50 undiagnosed pleural effusions, TB (50%) was the most common etiology. The overall diagnostic yield of semirigid thoracoscopy in this study was 74%. Our study showed that CBNAAT of pleural biopsies had a sensitivity of 36% only but a specificity of 100%. The sensitivity of CBNAAT was not far superior to the conventional culture. CONCLUSION: Tuberculosis (TB) is a common cause of undiagnosed pleural effusion in our set-up. CBNAAT testing of pleural biopsy, though, is a poor rule-out test for pleural TB, but it may aid in the early diagnosis of such patients.

Spirometric abnormalities in patients with sleep-related breathing disorders.

INTRODUCTION: Patients with sleep-related breathing disorders (SRBD) have various structural and functional abnormalities of the upper airway during sleep which may get reflected on their pulmonary function tests. The aim of the study was to find the correlation between the spirometric indices and snoring, grades of apnea-hypoapnea index (AHI), and STOPBANG. There is scarcity of literature showing correlation of STOP BANG with spirometric variables. MATERIAL AND METHODS: Patient with SRBD fulfilling the inclusion and exclusion criteria were enrolled. The pretest probability sleep score STOPBANG and polysomnography (PSG) were calculated for all the patients. Spirometric indices like forced expiratory volume in one sec (FEV1), forced vital capacity (FVC), postbronchodilator ratio FEVI/FVC (PBDR), and peak expiratory flow rate (PEFR) were studied. Their association with snoring, different grades of obstructive sleep apnea (OSA), and STOPBANG were evaluated using statistical analysis. RESULTS: A total of 70 patients were enrolled. Abnormalities of spirometric indices were found to be common in patients with SRBD but their association with snoring, grades of OSA, and STOPBANG were not statistically significant. There is no statistically significant correlation between body mass index (BMI) and grades of AHI. CONCLUSION: This study found no statistically significant correlation between spirometric parameters and STOPBANG and degree of AHI. Primary care physicians should be aware that obstructive lung disease does coexist with the sleep disordered breathing but as per this study, their statistically significant association needs further validation.