Peritoneal fluid analysis is a laboratory test to examine fluid that has collected in in the area of the abdomen that contains the gastrointestinal organs. This area is called the peritoneal space.

The sample of fluid is removed from the periotoneal space using a needle and syringe.

The health care provider will clean and numb a small area of your belly area (abdomen). Next, the doctor inserts a needle through the skin of your abdomen, and into the peritoneal space, and withdraws a sample of fluid. The fluid collects into a tube (syringe) attached to the end of the needle.

See: Abdominal tap

The fluid is sent to a laboratory where it is examined. Tests will be done on the fluid to measure red and white blood cell counts, protein, and albumin, and to check for bacteria and fungi. Occasionally, tests for glucose, amylase, ammonia, alkaline phosphatase, LDH, cytology, and other substances are done.

Let your health care provider know if you have any allergies to medications or numbing medicine, are taking any medications (including herbal remedies), have any bleeding problems, or might be pregnant.

You may feel a stinging sensation from the numbing medicine, or pressure as the needle is inserted.

If a large amount of fluid is withdrawn, you may have dizziness or lightheadedness. Tell the health care provider if you feel dizzy.

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

It is also done to remove large amounts of fluid from the peritoneal space in people who have liver disease.

• Bile-stained fluid may mean you have a gallbladder problem.
• Bloody fluid may indicate tumor or injury.
• High white blood cell counts may be a sign of peritonitis.
• Milk-colored peritoneal fluid may be a sign of carcinoma, lymphoma, tuberculosis,or infection.

Other laboratory abnormalities may be due to a problem in the intestines or abdominal organs. Large differences between the concentration of albumin in the peritoneal fluid and in your blood may point to heart, liver, or kidney failure. Small differences may suggest towards cancer or infection.

• Damage to the bowel, bladder, or a blood vessel in the abdomen from a needle puncture
• Infection
• Low blood pressure
• Shock

Garcia-Tsao G. Cirrhosis and its sequelae. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 157.