Thoracentesis

Definition
Thoracentesis is a procedure to remove fluid from the space between the lining of the lungs (pleura) and the chest wall. Normally, there is only a very small amount of fluid in this space, but when excess fluid accumulates, it is called a pleural effusion and can be removed by a thoracentesis.

How is the test performed?
A small area of skin on either the back or the chest is cleansed with a sterilizing solution. Some numbing medicine (local anesthetic) is injected in this area. A needle is then placed into the space between the chest wall and the lining of the lungs where the fluid has accumulated and the fluid is withdrawn and sent to the laboratory for analysis.

How the test will feel:
You will lie on a bed or sit on the edge of a bed or chair with your head and arms resting on a table. The skin around the procedure site will be prepped with sterilizing solution and the area will be draped. A local anesthetic is injected into the skin. You will feel a stinging sensation when the local anesthetic is injected, and you may feel a sensation of pressure when the needle is inserted into the pleural space.