ascitesanalyse

Ascitesanalyse refers to the diagnostic analysis of ascitic fluid obtained by paracentesis to determine the cause of ascites and guide treatment. The procedure is typically performed to evaluate new or worsening ascites, suspected infection, suspected malignancy, pancreatitis, nephrotic syndrome, or post-treatment assessment.

The analysis usually includes a bedside macroscopic assessment and laboratory measurements of the ascitic fluid, along with cytology and microbiology as indicated. Common laboratory tests are total protein, albumin concentration, and the serum to ascites albumin gradient (SAAG). Additional analyses may include cell count with differential, glucose, lactate dehydrogenase (LDH), amylase, and triglycerides. Cytology is used to detect malignant cells, while cultures and Gram stain are used to identify infectious etiologies. In cases of suspected infection, especially spontaneous bacterial peritonitis, a polymorphonuclear leukocyte (PMN) count of 250 cells/mm3 or higher in the ascitic fluid supports the diagnosis.

SAAG calculation (serum albumin minus ascitic fluid albumin) helps classify ascites. A SAAG of 1.1 g/dL (11 g/L) or higher suggests portal hypertension-related ascites (e.g., cirrhosis, congestive heart failure, Budd-Chiari syndrome). A SAAG below 1.1 g/dL points to non-portal hypertensive causes such as peritoneal carcinomatosis, tuberculosis, pancreatitis, or nephrotic syndrome. Specific fluid findings can indicate chylous ascites (triglycerides >200 mg/dL) or pancreatic ascites (elevated amylase).

Results guide management, including antibiotic therapy for infections, consideration of diuretics, albumin administration in selected conditions, and oncologic or surgical referrals as appropriate.