Paracentesis is a procedure to take out
fluid that has collected in the belly (peritoneal fluid). This fluid buildup is called
ascites . The fluid taken from your belly will be sent
to a lab to be studied and looked at under a microscope. Results will be ready
in a few hours.
No infection, cancer, or
abnormal values are found.
Several tests may be done on
- Cell counts. A high number of
white blood cells (WBCs) in the fluid may mean
inflammation, infection (peritonitis), or cancer are present. A
high WBC count and a high count of certain white blood cells (called
polymorphonuclear leukocytes, or PMN) may mean a certain type of infection
inside the belly called spontaneous bacterial peritonitis (SBP).
- Serum-ascites albumin gradient (SAAG). The
SAAG compares the level of protein in the fluid to the level of protein in the
blood. High protein levels in the fluid may mean cancer,
nephrotic syndrome, or
pancreatitis. Low protein levels in the fluid may mean
cirrhosis or clots in veins of the liver are
- Culture. A
culture can be done on the fluid to see whether
bacteria or other infectious organisms are present.
- Lactate dehydrogenase (LDH). High levels of
enzyme LDH may mean infection or cancer is
- Cytology. Abnormal cells in the fluid may
mean cancer is present.
- Amylase. High levels of amylase
may mean pancreatitis or that there is a hole in the intestine.
- Glucose. Low levels of
glucose may mean infection.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
blood thinners (anticoagulants) or aspirin, which can
increase the chance of bleeding.
- Having blood, bile, urine, or
feces in the fluid sample.
- Not being able to stay still during the
- Having scars inside the belly
(adhesions) from any belly surgery in the past.
What To Think About
Sometimes doctors use fluids put
into the belly to check for injuries. This is called peritoneal lavage. During
this procedure, a doctor uses a paracentesis needle to put a salt (saline)
fluid into the belly. The fluid is then taken out through the same needle. If
the fluid that comes out is bloody, the bleeding is probably being caused by an
injury inside the belly.
Other Works Consulted
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.