What is it?

A paracentesis, also called an abdominal tap, takes out fluid in the abdominal cavity, the area between the spine and belly wall. A needle and syringe inserted into the abdomen is used to extract the fluid.

What is for?

A paracentesis can find out the cause of fluid buildup in this space or find out if the buildup is infected. A paracentesis is sometimes done to relieve belly pain.

How to prepare

  • Tell your doctor about your medical history and medications you are taking
  • Before the procedure, you will be asked to empty your bladder. If you are having problems urinating, a catheter may be placed in your bladder to drain urine during the procedure.


  • Bleeding
  • Infection
  • Rapid drop in blood pressure
  • Structural injuries within the abdomen

What happens during?

  • An I.V. line is used to supply fluids and medications
  • You will be awake
  • Ultrasound may be used to show images inside your abdomen. The images show precisely where the excess fluid is located and where the needle should be inserted.
  • Anesthesia is used to numb the area of the incision site
  • Once the area is numb, the needle is inserted and fluid and extracted into the needle
  • If only a sample of fluid is needed, the needle is removed after only a small amount of fluid is obtained
  • A syringe or tube may be attached to the needle to collect and drain large amounts of fluid
  • Once the necessary amount of fluid is drained, the needle is removed. If a syringe or tube is used, those are also removed.
  • Pressure is used at the incision site to prevent bleeding or fluid leakage
  • Bandaging is placed over the incision site

What happens after?

  • If a sample of fluid was needed, the sample is sent to a lab for analysis
  • You will be in a recovery room for approximately 1 to 2 hours before being sent home
  • You should limit activity for about 24 hours after the procedure
  • You should be able to take the bandage off the incision site 24 hours following the procedure
  • Regularly check the incision site for signs of infection

Side effects

  • A fever of 100°F or higher
  • Bleeding or fluid leakage from the incision site
  • Bloody urine
  • Dizziness, fainting or lightheadedness
  • Infection at the incision site
  • Pain that doesn’t go away despite using pain medications
  • Shortness of breath
  • Stomach pain not related to the incision site
  • Swelling in the abdomen