Distinguishing Exudative from Transudative Effusion by Using Pleural Fluid Cholesterol and Bilirubin in Comparative Study to Light’s Criteria

Abstract

Background: Pleural effusions are often classified into exudates and transudates based on certain biochemical
parameters which include protein; lactate dehydrogenase (Light’s criteria); cholesterol and bilirubin, so the
aim of the study is to evaluate the importance of pleural fluid cholesterol and bilirubin in differentiating
exudative from transudate pleural effusion.
Method: Fifty patients with pleural effusion were evaluated for pleural fluid protein, lactate dehydrogenase
(LDH), cholesterol and bilirubin and compared simultaneously with drawn blood sample for protein, LDH
and bilirubin.
Results: In this study cholesterol in pleural fluid has a 94%, 100% sensitivity and specificity respectively and
bilirubin ratio (pleural fluid bilirubin/serum bilirubin) has a sensitivity of 88% and specificity of 85% while
the parameters of Light’s criteria i.e. protein ratio (fluid protein/serum protein) has 88%, 85% sensitivity and
specificity respectively and LDH ratio (fluid LDH/serum LDH) has a sensitivity of 100% and specificity of
71%.
Conclusion: Pleural fluid cholesterol and bilirubin ratio have a better sensitivity and specificity in
differentiating exudative from transudative pleural effusion than the parameters of Light’s measures.