Objective: To evaluate the efficacy of thoracentesis and pleural biopsy in the diagnosis of pleural inflammatory diseases. Methods: A retrospective study of 82 thoracenteses performed over a 42-month period in an internal medicine ward in Rio de Janeiro was conducted. Biochemical, cytological, and microbiological features of the pleural effusion, as well as the histopathological examination of the pleural tissue, were analyzed according to the final diagnosis. The sensitivity, sensibility, and predictive efficacy in the diagnosis of tuberculosis were calculated using different cut-off values of protein concentration and lymphocyte percentage. Results: Of the 82 patients, 73 (89%) had tuberculosis. This was the only diagnosis among patients aged 35 years or less. The negative predictive value (PV) raised from 17.1% to 66.7% when 4.5 and 2.5 g/dl, respectively, were used as cut-off values for protein concentration in the pleural fluid. Using 70% as the cut-off value for lymphocyte percentage in pleural fluid, negative PV was 100% and positive PV was 94.2%. Acid fast bacilli staining of the pleural fluid was negative in all samples. The sensitivity of the histopathological examination of the pleural tissue was 69.2% for the diagnosis of tuberculosis. Conclusions: Tuberculosis was the most common cause of pleural effusion in all age groups. Histopathological examination had the highest sensitivity to confirm tuberculosis. The authors suggest that, in populations with a high prevalence of tuberculosis, pleural tissue biopsy should be performed simultaneously with thoracentesis.
Pleurisy; Needle biopsy; Tuberculosis; Health services
