What is Paracentesis?

Paracentesis is a medical procedure to remove fluid that has collected in the abdomen, or belly. It can be done for several reasons, but mainly for a condition known as ascites, which specifically refers to abdominal fluid build-up. Other reasons for the procedure include testing, diagnosis, damage assessment and pain relief from a variety of factors, such as cancer or trauma to the area.

The paracentesis procedure is relatively simple, involving the insertion of a long needle to the affected area for the purpose of extracting some or all of the fluid. It can usually be done at a doctor's office, as well as in a hospital or emergency room when necessary. If the factors that caused the fluid buildup in the abdomen are unknown, a sample of the fluid will typically be sent to an outside lab for testing.

A patient undergoing a paracentesis generally will have to lie down with his or her abdomen exposed. The area where the needle will enter must be treated with an antiseptic and numbed with an anesthetic. The needle is inserted with a sheath, or tube, that will remain once the needle is removed. It is through this sheath that fluid is extracted and drained into a bottle or other container. A paracentesis will typically involve little or no pain, aside from that caused by the fluid itself, which is often relieved by the fluid's removal. A patient's blood pressure must also be monitored during the procedure since a drop in this diagnostic may signify a complication.

A common reason for fluid buildup and the need for a paracentesis is abdominal infection caused by bacteria. The fluid can also be due to certain kinds of cancer, reinforcing the importance of testing after administering the procedure. Severe trauma to the belly can also cause fluid to build up, and the fluid must often be tested to assess the amount of damage to the surrounding internal organs. In any of these cases, the presence of the fluid can become dangerous, if not extremely uncomfortable or painful, when left untreated.

Some factors can affect the ability to perform a paracentesis. The presence of drugs such as blood thinners in a patient's system prior to the operation may result in a delay. A pregnant patient may also require the doctor to do the procedure differently, if at all. Some diagnostics, such as blood tests, may be administered before a paracentesis to avoid unnecessary complications.