Light’s Criteria Versus Costa’s Criteria in Differentiating Transudative Exudative Pleural Effusions

Introduction: Aim of this study is to compare COSTA’S and LIGHT’S criteria in identifying exudative from transudative pleural effusions.Materials Methods: A prospective study that is hospital-based was conducted at GHCCD, during Jan 2017 to August 2018 in 80 patients who presented with pleural effusion. Light’s and Costa’s criteria were applied to differentiate them into transudative and exudative effusions.Results: Among the pleural effusions, 83.75% were exudates and 16.25% were transudates. Tuberculous effusion (45%) was the most common among exudates, and chronic kidney disease (10%) was the most common among the transudates. On biochemical analysis of effusions, the mean pleural fluid cholesterol levels were 74.02±20.51mg/dl and 29.23±7.44mg/dl in exudative and transudative effusions respectively. On ROC analysis, the cut-off value for pleural fluid cholesterol was considered 50mg/dl and 29mg/dl for exudative and transudative effusions respectively. The mean pleural fluid LDH cut-off values on ROC analysis was 231U/L for exudative effusions and 231U/L for transudative effusions. The sensitivity, specificity, PPV, NPV of Lights criteria observed to be 100%, 61.5%, 93.05% 100% with accuracy of 93.75% whereas the values of Costa’s criteria were 97%, 92%, 98%, 85.7% with accuracy of 96.25% in differentiating exudates and transudates. P-value was statistically significant for both criteria.Conclusion: Pleural fluid LDH and cholesterol are found to be excellent parameters to differentiate transudates and exudates. Costa’s criteria is simple, convenient with almost equal sensitivity and more specificity in comparison to Light’s criteria, with fewer pleural fluid parameters compared to Light’s criteria.