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.
It's normal to have a small amount of fluid in the pleural space. But too much fluid can build up because of problems such as infection or inflammation of the tissues around the lungs. The procedure may be done to help with shortness of breath and pain caused by the fluid buildup. Or your child may have it done so the doctor can test the fluid to find the cause of the buildup.
The doctor will put a long, thin needle or a thin plastic tube called a catheter between two of your child's ribs. The doctor will use the needle or catheter to take fluid out.
Your child may get medicine before the procedure. This helps with pain and helps your child relax. The procedure will take about 15 minutes.