Comparing between serum-pleural effusion albumin gradient and Light’s criteria in differentiating exudative from transudative pleural effusion

Abstract

Background: Approximately about 10% of patients with internal diseases suffer from pleural effusion, For diagnosing and treatment plan the first step is to determine whether the effusion is exudate or transudate. If this classification is not correct, it may result in severe complications.

Aim: This study is conducted to evaluation the diagnostic value of Serum Effusion Albumin Gradient (SEAG) criteria in comparison to Light’s criteria to differentiate exudative from transudative pleural effusion.

Methods: In this prospective study, population was grouped as exudative and transudative effusions depending on their confirmed aetiology, and was compared with the classification of Light’s criteria and SEAG. Sensitivity and specificity of each indicator of Light’s criteria were also compared with those of SEAG.

Results: 41 of 45 exudates and 36 of 38 transudates were classified correctly using SEAG, the sensitivity and specificity were 91.1% and 94.7% respectively, meanwhile 43 exudates and 28 transudates were classified correctly using Light’s criteria with sensitivity 95.6% and specificity 73.7%, pleural fluid protein/serum protein ratio  had sensitivity of 86.05%, specificity of 80%, Pleural fluid to serum LDH ratio had sensitivity of 88.57%, specificity of 70.83%, Pleural fluid LDH index was found to have sensitivity of 84.44%, specificity of 84.21%.

Conclusion: SEAG is better in identifying the transudative effusions than Light’s criteria, but the latter still have a slight advantage in identifying exudative effusions.