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 (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 ) 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
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
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.