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Overview of the Thoracentesis Procedure

written by: Leigh A. Zaykoski•edited by: Leigh A. Zaykoski•updated: 7/15/2009

The thoracentesis procedure can be used to relieve pain and shortness of breath caused by pleural effusion or to diagnose the cause of excess pleural fluid in the thoracic cavity. Find out how this procedure is performed and how it is used.

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    Uses of the Procedure

    The thoracentesis can be used to figure out why a patient has excess pleural fluid in the chest cavity. Because excess pleural fluid can cause pressure, pain, and shortness of breath, the procedure can also be used to remove some of the excess fluid and relieve these symptoms. Once the test is used to determine the cause of a pleural effusion, doctors may begin treating that condition.

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    Before this procedure is done, your doctor may order a chest x-ray or laboratory tests such as the complete blood count and PT/PTT. You will also be asked if you are taking any medications or are allergic to any medications. Blood thinners can cause bleeding after this kind of procedure, so you may be asked to stop taking them a few days before your appointment. If you have lung disease or have had lung surgery, you should inform your doctor. Scarring from previous lung surgery may make it difficult to perform a thoracentesis.

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    How the Procedure is Performed

    Your procedure may be done at a private physician's office or in the x-ray department of a hospital. You will be asked to disrobe and wear a hospital gown so that doctors and nurses have easy access to the procedure site. Before the test, you will be positioned against a padded support that allows you to remain seated while leaning forward.

    The needle site will be between your ribs and may be selected based on the results of an ultrasound or x-ray. Once the site has been identified, it will be cleaned with antiseptic and numbed with a local anesthetic. Your doctor will insert a longer needle that is attached to a syringe or tube into the space. Excess pleural fluid is removed and some of it is sent to the laboratory for analysis. Once the procedure is complete, the site is bandaged to keep it clean and protect it from injury.

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    While the thoracentesis procedure is usually a safe one, there are some risks. Infection and bleeding can occur, particularly if you do not follow the doctor's instructions for care of the puncture site after the test has been completed. Partial lung collapse can occur if the needle punctures the lung and allows air to collect in the pleural space. If a large amount of pleural fluid is removed, pulmonary edema may also occur.

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    WebMD. "Thoracentesis." Accessed 30 June 2009.