Peritoneal fluid analysis

Definition

Peritoneal fluid analysis is a test to examine fluid accumulated in the peritoneal space (the abdominal space that houses the gastrointestinal organs). The sample is obtained by an abdominal tap.

How the test is performed

A sample of fluid is obtained by abdominal tap. The physicians will sterilize and numb a small area of your abdomen with a small needle. Next, a larger needle will be inserted into the peritoneal space and the fluid will be withdrawn.

Occasionally, vacuum bottles are used to draw off large amounts of fluid. The fluid is typically examined in the laboratory for appearance, red and white blood cell counts, protein and albumin, bacteria and fungi. Occasionally, tests for glucose, amylase, ammonia, alkaline phosphatase, LDH, cytology, and other substances are performed.

How to prepare for the test

You must sign a consent form. Immediately before the abdominal tap, empty your bladder.

How the test will feel

There may be a stinging sensation from the anesthetic and a feeling of pressure as the needle is inserted. If a large amount of fluid is withdrawn, you may have a feeling of dizziness or light-headedness. Tell the health care provider if you become dizzy.

Why the test is performed

The test is performed to determine the cause of fluid in the abdomen, to detect whether trauma has caused internal bleeding, to detect a hole in the bladder, and to detect peritonitis.

What abnormal results mean

Milk-colored peritoneal fluid may indicate disease such as carcinoma, lymphoma, tuberculosis or infection. Bloody fluid may indicate tumor or trauma. Bile-stained fluid may indicate gallbladder problems. High white blood cell counts may indicate peritonitis or cirrhosis.

Other laboratory abnormalities may indicate problems in the intestines or abdominal organs. Large differences between the concentration of albumin in the peritoneal fluid and in your blood serum may point to heart, liver, or kidney failure as the cause of the fluid collection. Small differences may point more towards cancer or infection.

What the risks are

There is a slight chance of the needle puncturing the bowel, bladder, or a blood vessel in the abdomen. If a large quantity of fluid is removed, there is a slight risk of low blood pressure and even shock. There is also a slight chance of infection.