Abdominal Paracentesis: Why Paracentesis Is Performed

Therapeutic and Diagnostic Abdominal Paracentesis

Fluid in the Abdomen Can Be Painful.

If you have been told that you need abdominal paracentesis, you probably have fluid building up in your abdominal cavity.  You may be wondering how paracentesis is done, when it is necessary, and the risks associated with having this procedure. 

What is Paracentesis?

Paracentesis is the term used for removing fluid from the body for testing or because enough fluid has built up to cause complications.

Paracentesis can be done in many ways, and may remove fluid from the abdomen, knee, inner ear, eye or other places where fluid has built up.  

Why is Abdominal Paracentesis Done?

There are two types of abdominal paracentesis, diagnostic and therapeutic.  A diagnostic paracentesis is done to examine the fluid in the abdomen.   Determining the type of fluid present will help determine the cause of the problem. The second type, the therapeutic paracentesis, is performed is because there is enough fluid in the abdomen to cause additional problems such as decreased organ function and breathing problems.   

For example, during a diagnostic paracentesis fluid is taken from the abdomen to be tested in the lab and examined under a microscope, this may help diagnose the problem.  Paracentesis will determine if the fluid is blood, ascites (caused by the liver) or another issue.  

Another example: A patient with ascites, a fluid build up caused by liver problems, is having difficulty breathing.

  A therapeutic paracentesis may be performed to remove several liters of fluid and make breathing easier by reducing pressure inside the abdomen.

What Causes Fluid Buildup in the Abdomen?

Fluid can build up for many reasons, it can be caused by the presence of bacteria, liver disease, bleeding, or it may be a complication of abdominal surgery.

  The cause of the fluid build up may not be determined until the fluid is analyzed in a laboratory.

How is Abdominal Paracentesis Done?

Abdominal paracentesis is typically done as an outpatient procedure, unless the complications from the fluid build up warrant hospitalization.  The patient is usually awake during the procedure as anesthesia is not typically necessary.

The abdominal paracentesis may be performed using an ultrasound machine or a type of x-ray to guide the physician and minimize any unintended injury to the abdominal tissue.  

The procedure typically starts with an injection of numbing medication in the abdomen at the site where the paracentesis will be performed.  This will dramatically reduce any pain or discomfort during the procedure. Once the area is numb, a needle will be inserted into the abdomen.  The needle is guided to the area of the fluid collection and once it reaches the pocket of fluid, the fluid is gently pulled from the abdomen.  

Depending on the nature of the fluid collection, a small sample may be taken, or several liters of fluid may be removed using gentle vacuum pressure.


The Risks of Paracentesis

The most common complications of paracentesis are infection, bleeding, a decrease in blood pressure and accidental injury to the blood vessels or organ structures. Great pains are taken to minimize the risk of injury and infection.  The use of ultrasound or x-ray to guide the procedure helps to decrease the risk of accidental injury, and the use of sterile technique helps minimize the risk of infection.

For patients who experience low blood pressure during the procedure, IV fluids may be given or the procedure may be stopped and the removal of fluid slowed.

After Paracentesis

A small amount of bleeding from the site of the needle insertion is expected. This bleeding should decrease and eventually stop in the hours following the procedure.  Extensive bleeding, of the leakage of fluid from the site should be taken seriously and the physician who performed the procedure should be notified.  A trip to the Emergency Room may be in order.  

A small amount of redness at the site is also expected in the day or two following the procedure.  An increase in redness, pus or drainage from the site, the sensation of heat over the site and signs and symptoms of infection should be reported.  

Blood in the urine or stool that was not present prior to the procedure is a sign of a potentially serious complication and should also be reported immediately, or treatment should be sought in the Emergency Room.


Diagnostic and Therapeutic Abdominal Paracentesis.  Bruce Runyon, MD. Accessed March, 2015. http://www.uptodate.com/contents/diagnostic-and-therapeutic-abdominal-paracentesis

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