Key Points

• Thoracentesis is a procedure to remove excess fluid in the pleural space (the space between the lungs and the chest wall).
• When fluid builds up in the pleural space, it's called a pleural effusion. A lot of fluid can press on the lungs and make it hard to breathe.
• Certain conditions, such as heart failure, lung infections, and tumors, can cause a pleural effusion.
• Thoracentesis is done to help find the cause of a pleural effusion. It also may be done to help you breathe easier if there's a lot of fluid in the pleural space.
• Before thoracentesis, your doctor will talk to you about the procedure and how to prepare for it.
• Thoracentesis usually takes about 10 to 15 minutes. If there's a lot of fluid, it may take up to 45 minutes.
• Your doctor inserts a needle or tube between your ribs and into the pleural space. He or she draws out the excess fluid. Once the fluid is removed, the doctor takes out the needle or tube. A small bandage is placed on the site where the needle or tube was inserted.
• After thoracentesis, you may need a chest x ray to check for any lung problems. Your blood pressure and breathing will be checked for up to a few hours to make sure you don't have complications. Your doctor will let you know when you can return to your normal activities, such as driving, physical activity, and working.
• The fluid removed during thoracentesis is studied to find the cause of the pleural effusion. Once the cause is known, your doctor will talk to you about a treatment plan.
• Thoracentesis usually doesn't cause serious problems, but some risks are involved. These include pneumothorax, or collapsed lung; pain, bleeding, bruising, or infection where the needle or tube was inserted; and liver or spleen injury (very rare). Most of these complications get better on their own, or they're easily treated.