investigations
Last reviewed 01/2018
The following are standard tests in suspected ascites:
- ultrasound
- diagnostic paracentesis in which 30 to 50 ml of fluid is withdrawn. This will enable identification of:
- protein content: albumin and total protein
- malignant cells
- bacteria
- white blood cells
- glucose
If there is a very high white cell count, i.e. greater than 250/mm cubed, which is predominantly polymorphs, then this is suggestive spontaneous bacterial peritonitis. Often such an infection is due to coliforms.
A sample of fluid that contains more than one type of organism suggests possible bowel perforation or a contaminated sample. Other tests on the ascitic fluid may be considered:
- amylase - helps detect pancreatic ascites and gut perforation in the peritoneal cavity
- tuberculous smear and culture