Thoracentesis is a procedure to remove fluid from the space between the lining of the outside of the lungs (pleura) and the wall of the chest.
Pleural fluid aspiration; Pleural tap
How the Test is Performed
The test is done in the following way:
How to Prepare for the Test
No special preparation is needed before the test. A chest x-ray or ultrasound will be done before and after the test.
How the Test will Feel
You will feel a stinging sensation when the local anesthetic is injected. You may feel pain or pressure when the needle is inserted into the pleural space.
Why the Test is Performed
Normally, very little fluid is in the pleural space. A buildup of too much fluid between the layers of the pleura is called a pleural effusion.
The test is performed to determine the cause of the extra fluid, or to relieve symptoms from the fluid buildup.
Normally the pleural cavity contains only a very small amount of fluid.
What Abnormal Results Mean
Testing the fluid will help your provider determine the cause of pleural effusion. Possible causes include:
If your provider suspects that you have an infection, a culture of the fluid may be done to test for bacteria.
Risks may include any of the following:
A chest x-ray is commonly done after the procedure to detect possible complications.
Blok BK. Thoracentesis. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 9.
Chernecky CC, Berger BJ. Thoracentesis - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:1068-1070.
Review Date: 7/20/2018
Reviewed By: Allen J. Blaivas, DO, Division of Pulmonary, Critical Care, and Sleep Medicine, VA New Jersey Health Care System, Clinical Assistant Professor, Rutgers New Jersey Medical School, East Orange, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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