A study on ascitic fluid total protein and serum ascites albumin gradient in evaluation of ascites in children

Abstract

Background: Ascites is the pathologic accumulation of fluid within the peritoneal cavity. Because many diseases can cause ascites, in particular cirrhosis, samples of ascitic fluid are commonly analyzed in order to develop a differential diagnosis. The concept of transudate versus exudate, as determined by total protein measurements, is outdated and the use of serum-ascites albumin gradient as an indicator of portal hypertension is more accurate. Aim: To compare the diagnostic value of Serum Ascites Albumin Gradient and the Ascitic Fluid Total Protein concentration in separating exudative and transudative causes of ascites and to study the value of Serum Ascites Albumin Gradient in separation of ascites related to Portal hypertension from ascites not related to Portal hypertension Methodology: It was a Hospital based descriptive study carried out at Kamineni Institute of Medical Sciences. We selected 40 patients admitted with clinical ascites. Results: Of the patients studied 57.5% cases were females and 42.5% cases were males. Highest number of cases were due to Nephrotic syndrome (37.5%)followed by Cirrhosis of liver (22.5%), Tuberculous ascites (20%) and Cardiac ascites (15%). Ascitic fluid total protein (AFTP) at a cut off of 2.5 g/dl, had a Sensitivity of 82.5%, Specificity of 60%, Positive predictive value of 85.5%, Negative Predictive value of 46.15% and Accuracy of 78% in classifying ascites as ‘Transudate’ or ‘Exudate’. Serum Ascites Albumin Gradient (SAAG) of 1.1g /dl had a Sensitivity of 40%, Specificity of 40%, Positive predictive value of 80%, Negative predictive value of 27.6% and Accuracy of 50% in classifying ascites as ‘Transudate’ or ‘Exudate’. Serum Ascites Albumin Gradient (SAAG) at 1.1 g/dl had a Sensitivity of 100%, Specificity of 93.5%, Positive Predictive valueof 92.5%, Negative predictive value of 100% and Accuracy of 96% in classifying ascites as ‘High gradient’ (due to Portal hypertension)or ‘Low gradient’ (non Portal) hypertensive conditions. Conclusion: Serum Ascites albumin gradient is found to be superior to ascetic fluid total protein in the diagnosis of ascites and recommended for classification of ascites as ‘High-gradient’ or ‘Low gradient’ ascites instead of ‘Transudative’ or ‘Exudative’ ascites. SAAG is superior to transudate —exudate concept not only becauseof its high diagnostic accuracy but also because of it being a better approach to the pathogenesis of ascitic fluid collection.