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Paracentesis is a procedure to take out fluid that has collected in the belly (peritoneal fluid). This fluid buildup is called ascites. Ascites may be caused by infection, inflammation, an injury, or other conditions, such as cirrhosis or cancer. The fluid is taken out using a long, thin catheter. If your prescribing doctor has asked, the fluid is sent to a lab and studied to find the cause of the fluid buildup. Paracentesis also may be done to take the fluid out to relieve belly pressure or pain in people with cancer or cirrhosis.

Need to Know

Nice to Know
  • You will be asked to sign a consent form before the procedure is performed
  • Tell your radiologist about any allergies, especially to local or general anesthetics Bring a list of medications you are currently taking and their dosages
  • If you are taking a blood thinner or aspirin product, the physician will instruct you when to stop taking these medications
  • Inform your radiologist if you are pregnant
  • Wear comfortable, loose-fitting clothing
  • You can request a gown to wear during your treatment
  • Most patients feel minimal discomfort after the procedure


How Does It Work?

Using ultrasound guidance the abdomen is scanned to show where the excess fluid build up is and then it is drained using sterile technique to prevent infection. 

What Happens — Before, During, and After?

  • A clinical staff member will bring you into the procedure area. Your doctor will greet you, review the procedure, and answer any questions you may have. You will be lying down on your back. Ultrasound will be used to scan your abdomen. An area will be selected for the paracentesis catheter to be placed.
  • You may feel a brief, sharp sting when the numbing medicine is given. When the paracentesis catheter is put into your belly, you may feel a temporary sharp pain or pressure.
  • You may feel dizzy or lightheaded if a large amount of fluid is taken out. Tell your doctor if you do not feel well during the test.
  • After the procedure, you may have some clear fluid draining from the site, especially if a large amount of fluid was taken out. The drainage will get less in 1 to 2 days. A small gauze pad and bandage may be needed.
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How Should I Prepare?

There are things you can do to make your experience more comfortable, and many of these will depend on your individual preferences. You might like to keep a list of questions or – as you’re doing now- educate yourself about the procedure.

Another important part of your preparation will be guided by your doctor:

  • Your doctor may ask you to stop taking aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or blood thinners (such as Coumadin, Warfarin, Plavix, Fragmin) for a time before the procedure.

Some of your preparation will need to be timed to the procedure:

  • Take your medications as instructed
  • When you arrive, make sure the clinical staff member and radiologist know about any allergies you may have, especially allergies to local anesthetics (such as lidocaine). If there’s any chance you might be pregnant, tell your radiologist.
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What Should I Bring?

  • Wear comfortable, loose-fitting clothes
  • Wear comfortable shoes
  • Avoid bringing jewelry or valuables
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What Are the Benefits and Risks?

The benefits of Paracentesis could be:

  • Find the cause of fluid buildup
  • Diagnose an infection in the peritoneal fluid
  • Check for certain types of cancer, such as liver cancer
  • Remove a large amount of fluid that is causing pain or difficulty breathing or that is affecting how the kidneys or the intestines (bowel) are working

Risks you should be aware of include:

  • There is a very small chance that the paracentesis needle may poke the bladder, bowel, or a blood vessel in the belly. There is also a small chance of infection at the puncture site.
  • Keep in mind that this information is general. Your radiologist is the best source of information about how these risks and benefits may apply to you.

Where Can I Get This Exam?


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