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Lung Disease & Respiratory Health Center

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Thoracentesis is a procedure to remove fluid from the space between the lungs and the chest wall called the pleural space. It is done with a needle camera.gif (and sometimes a plastic catheter) inserted through the chest wall. Ultrasound pictures are often used to guide the placement of the needle. This pleural fluid may be sent to a lab to determine what may be causing the fluid to build up in the pleural space.

Normally only a small amount of pleural fluid is present in the pleural space. A buildup of excess pleural fluid (pleural effusion camera.gif) may be caused by many conditions, such as infection, inflammation, heart failure, or cancer. If a large amount of fluid is present, it may be hard to breathe. Fluid inside the pleural space may be found during a physical examination and is usually confirmed by a chest X-ray.

Why It Is Done

Thoracentesis may be done to:

How To Prepare

You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.

Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this procedure, fill out the medical test information form(What is a PDF document?).

Tell your doctor if you:

Also, certain conditions may increase the difficulty of thoracentesis. Let your doctor know if you have:

  • Had lung surgery. The scarring from the first procedure may make it difficult to do this procedure.
  • A long-term (chronic), irreversible lung disease, such as emphysema.

A chest X-ray is usually done before the procedure. Your doctor may order certain blood tests, such as a complete blood count (CBC) and clotting factors, before your procedure.

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WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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