IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 17, Issue 2 Ver. 13 February. (2018), PP 13-18 www.iosrjournals.org DOI: 10.9790/0853-1702131318 www.iosrjournals.org 13 | Page “Comparative Analysis of Biochemical Parameters To Differentiate Transudative And Exudative Pleural Fluid” Shah N 1 , Trikha S 1 , Jatav O.P 1 , Shah R 2 , Singh N 1 , Rajput S 1 1- Dept. Of Medicine, G.R.Medical College, Mpmsu, India 2- Dept. Of Pathology, Svbch ,Silvassa, India Corresponding author: Shah N Abstract : Background: Light’s criteria is the gold standard to differentiate transudative pleural effusion (PE) from exudative PE, but it requires four biochemical estimations which, in developing countries such as India, may not be feasible in every patient due to economic constraints. Aims & Objectives: To evaluate the comparative usefulness of pleural fluid biochemical parameters with relative usefulness of pleural cholesterol to the traditional Light’ criteria. Methodology: This observational nonrandomized multiple arm prospective study was carried out in a group of new PE cases, admitted between December 2015 to September 2017 in the Department of Medicine at Gajra Raja Medical College, Gwalior, India. A total of 100 adult patients of both gender were selected by adhering strictly to certain inclusion and exclusion criteria. Statistical Analysis : Sensitivity, specificity, positive predictive value and negative predictive value of different biochemical parameters single or in combination were analyzed by SPSS 19 software. Strict confidentiality of the study reports was maintained and all the queries and apprehensions of the patients and their families were addressed with utmost care. Prior to initiating the study, counselling of the patients and their families were done and an informed written consent was taken. Results: According to their etiology, 88 cases of effusion were exudates & 12 transudates. Using Pleural Cholesterol range of 45-60 mg/dl and values for pleural fluid protein & LDH (Light’s criteria), the best diagnostic power corresponded to the combination of pleural cholesterol and LDH; cholesterol level between 45-60 mg/dL and/or LDH over 200 IU/L differentiate exudates from transudates with a sensitivity o and a specificity of >90%. Conclusion : The measurement of pleural cholesterol and LDH permits the separation of pleural exudates from transudates with accuracy similar to the original report of Light et al., with the advantage of requiring only two laboratory determinations and no simultaneous blood sample, especially in a country like India where financial and technical constraints are immense. Keyword’s : Pleural Effusion, Transudate, Exudate, Light’s Criteria, Pleural Cholesterol , Pleural LDH. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 10-02-2018 Date of acceptance: 26-02-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Pleural effusion (PE) is of two types depending on the underlying pathophysiology, that is, „„transudates‟‟ and „„exudates.‟‟ Transudates occur when the mechanical factors influence the formation or reabsorption of pleural fluid, like a decrease in plasma oncotic pressure or elevated systemic or pulmonary hydrostatic pressure. Exudate results from inflammation or irritation or other disease process involving the pleura, resulting in increased permeability. 1 TRANSUDATE OR EXUDATE Traditionally, serous fluids are classified as transudates or exudates. Transudates derive from ultra filtration across a membrane and have a low protein content, whereas exudates are formed by active secretion or leakage and have a high protein content. The presence of a transudative effusion implies a non-inflammatory process caused by a disturbance of hydrostatic or colloid osmotic pressure with no pleural disease involvement. In contrast, an exudates implies involvement of the pleura by an inflammatory or malignant process causing increased capillary permeability. When pleural fluid is sent for examination, the laboratory is often asked to determine whether it is a transudate or an exudate. In reality, the question being asked is what is the cause of this effusion? The first step in determining the etiology of a PE should be to find out whether it is a transudate or an exudate. Light et al., used pleural fluid and serum levels of protein and LDH to establish criteria for differentiating transudates from exudates. This high diagnostic accuracy made the criteria of Light et al., the „gold standard‟ for initial categorization of PE. 2,3 However, Light‟s criteria require four biochemical estimations which, in developing countries such as India, may not be feasible in every patient due to economic constraints. Also, several prospective studies were unable to reproduce the results obtained by Light et al. 4,5,6