What is thoracentesis?

Thoracentesis (say "thor-uh-sen-TEE-sis") is a procedure to remove fluid from the space between the lungs and the chest wall. This is called the pleural space. The procedure may also be called a "chest tap."

It is normal to have a small amount of fluid in the pleural space. Too much fluid can build up because of problems such as infection, heart failure, and lung cancer. The procedure may be done to help with shortness of breath and pain caused by the fluid buildup, or you may have it done so the doctor can test the fluid to find the cause of the buildup.

Your doctor will put a long, thin needle or a thin plastic tube, called a catheter, between two of your ribs. The doctor will use the needle or catheter to take fluid out.

You may get medicine before the procedure. This helps with pain and helps you relax. The procedure will take about 15 minutes. Most people go home shortly after. You can go back to work or your normal activities as soon as you feel up to it.

If the doctor sends the fluid to a lab for testing, it usually takes a few hours to get the results. Some of the test results may take a few days. The doctor or nurse will discuss the results with you.

How do you prepare for the procedure?

Preparing for the procedure

• Bring a list of questions to ask your doctors. It is important that you understand exactly what procedure is planned, the risks, benefits, and other options before your procedure.
• 
  Tell your doctors ALL the medicines and natural health products you take. Some of these can increase the risk of bleeding or interact with medicines. Your doctor will tell you which medicines to take or stop before your procedure.
• If you take blood thinners, ask your doctor if you should stop taking them before your procedure. Make sure that you understand exactly what your doctor wants you to do.
• You may need to stop taking certain medicines a week or more before your procedure, so talk to your doctor as soon as you can.
• Be sure to have someone take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.

What happens on the day of the procedure?

• Take off all jewelry and piercings.

At the hospital, surgery centre, or doctor's office

• 
  Bring a picture ID.
• The doctor may take a chest X-ray or use ultrasound or CT scan pictures to help find the exact spot where fluid has built up.
• The doctor will give you a shot of numbing medicine in the skin where the needle or catheter will go.
• The procedure will take about 15 minutes.
• The doctor may take a chest X-ray after the procedure.