Comparison Of Clinical Value Between Serum Ascites Albumin Gradient And Exudate-transudate Concept

Objectivel Ascites is pathologic accumulation of fluid within the peritoneal cavity. It is a familiar symptom and can be caused by various diseases. Traditionally, the ascetic fluid total protein concentration (AFTP) has been used to classify specimens into broad categories of exudative or transudative samples were classified as exudates if the AFTP was 25 g/L or more and as transudates if the AFTP was less than 25 g/L. This exudate-transudate concept was based on the assumption that fluid that formed by "exudation" from an inflamed or tumor-laden peritoneal surface was high in protein. Fluid that "transuded" from a normal peritoneal surface because of imbalance of Starling force. By lots of clinical observations, many problems and exceptions have been noted, however, with the exudate-transudate concept. Many infected or malignancy-related samples have been reported to have protein concentration in the transudate rang, and many samples obtained from patients with cirrhosis, heart failure or Budd-Chiari syndrome have had concentration in the exudate rang. Also the exudate-transudate concept makes no provision for those patients who have "mixed" ascites which have two cause or more of ascites formation. So the differential diagnosis of ascites remains a clinical problem. Since Hoefs brought forward serum ascites albumin gradient (SAAG) in 1978,many investigators have demonstrated that SAAGderectly correlated with portal pressure and was considered to be a credible parameter identifying portal hypertension and nonportal hypertension. Diagnostic accuracy of SAAG was or more 95%. Recently, importantce and clinical value of SAAG was accepted by many scholars overseas and recorded in professional textbook. The traditional methods based on exudate-transudate concept was obviously lagged the time, but it was also applied in most of our hospital and clinical biochemical laboratory. The aims of our study, on the one hand was to confirme the priority of SAAG as a parameter identifying the ascitec fluid cause, on the other hand, the research could attract attention of clinical and biochemical worker and shrink the gap between home and abroad.Materials and methods: Ninety-nine patients with ascites admitted to the first affitiated hospital Zheng Zhou University during the period between march 2003 and April 2004. The series consisted of 99 patients (69 men and 30 women; age range, 18 to 89 years). Patients with ascites included 61 patients with decompensated cirrhosis(posthepatitic cirrhosis in 56; alcoholic cirrhosis in 5), 18 patients with malignancy(9 malignancy with liver involvement), 9 patients with tuberculous peritonitis,5 patients with Budd-Chiari syndrome, 3 patients with heart failure, 3 patients with nephritic syndrome. In accordance with clinical sign(thoraco-abdominal wall varicosis,splenomegaly,ascitic fluid) and abdominal ultrasonography(splenomegaly, portal vein > 13mm, splenic vein > 7mm), ascitic fluid was classified as portal hypertensive and nonportal hypertensive ascitic fluid. All patients serum and ascites obtained in the same day and tested serum total protein, ascitic fluid total protein, serum albumin, ascitic fluid albumin, serum bilirubin, ascitic fluid bilirubin, ascitic fluid white blood cell number and specific gravity, respectively. SAAG was defined as the serum albumin concentration minus ascitic fluid albumin concentration. Finally, we analyzed and compared clinical value of SAAG and exudate-transudate concept. The data wereanalyzed by soft ware SPSS 10.0. p value of less than 0.05 was considered statisticallysignificant.Results:1. SAAG in group with portal hypertension and group in with nonportal hypertension was 21.69+5.24 and 9.44+4.20. SAAG in group with portal hypertension was significantly higher than that in group with nonportal hvpertension(p < 0.001).2. 76 of the 78 samples fit the expected pattern of high gradient in patientrs with portal hypertension and 18 of 21 samples fit low gradient in patients without partal hypertenson. Diagnostic accuracy of SAAG was...