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:
- Find the cause of excess pleural fluid (pleural effusion).
- Relieve shortness of
breath and pain caused by a pleural effusion.
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.
How It Is Done
This procedure may be done in your
doctor's office, in the X-ray department of a hospital, in an emergency room,
or at your bedside in the hospital. Your doctor may have a nurse assist with
You will need to take off all or most of your
clothes (you may be allowed to keep on your underwear if it does not interfere
with the procedure). You will be given a cloth or paper covering to use during
the procedure. During the procedure, you will be seated but leaning forward on
a padded bedside table. If your test is done in the X-ray department, X-rays or
ultrasound may be used to confirm the location of
fluid in your chest.