Publication:

Evaluation of diagnostic value of n-terminal pro brain natriuretic peptide in pleural fluid with cardiac origin

Background Pleural effusion is a common finding in patients. For a long time, a light criterion is used to analysis of pleural effusion for separation of transudative from exudative fluid. Sensitivity of light criteria is very high to determine exudative pleural effusion (98%). However, the ability of these criteria for ruling out of transudative effusions is low. For this reason, this study was carried out to determine the level of NT-proBNP in pleural fluid.

Methods A descriptive-analytic study was carried out on 21 patients with complaints of shortness of breath and diagnosis of pleural effusion. Pleural fluid was tapped in these patients and the following tests were performed: LDH, total protein, albumin, cell count, cell differentiation, cytology for malignant cells, ADA, smear for AFB, gram smear and culture.The results of all experiments were analyzed using SPSS V16.

Results Mean age of participants was 65 years. Male and female frequencies were 52.4 and 47.6, respectively. 33.3% of patients had CHF, 28.5% TB, 19.4% malignancy, 4.76% hydatid, and the rest left without diagnosis. A pleural fluid in 66.7% of participants was exudative and in 33.3% was transudative. The levels of NT-proBNP (Pg/ml) in serum and pleural fluid of patients with CHF were 11288.42 and 11036.81, but in malignant patient were 1721.68 and 713.59, respectively, and the levels of NT-proBNP in serum and pleural fluid in TB patient were 2429.30 and 2810.08, respectively. Also, there was no significant difference between the levels of serum and pleural effusion NT-proBNP in transudative and exudative fluid but the level of NT-proBNP was significantly higher in CHF patients compared to others.

Conclusions The results showed that the levels of NT-proBNP in serum and pleural fluid of cardiac patients are higher than other patients, but no significant difference in NT-proBNP between transudative and exudative pleural effusion.