Who Needs Thoracentesis?

You may need thoracentesis if you have a pleural effusion. A pleural effusion is the buildup of excess fluid in the pleural space (the space between the lungs and chest wall).

Thoracentesis helps find the cause of the pleural effusion. It also may be done to help you breathe easier, if there's a lot of fluid in the pleural space.

The most common cause of a pleural effusion is heart failure. This is a condition in which the heart can't pump enough blood to the body.

Other causes include lung cancer, tumors, pneumonia, tuberculosis, pulmonary embolism, and other lung infections. Asbestosis, sarcoidosis, and reactions to some drugs also can lead to a pleural effusion.

Diagnosing a Pleural Effusion

A pleural effusion is diagnosed based on your medical history, a physical exam, and test results.

Medical History

Your doctor will ask about your symptoms, like trouble breathing, coughing, and hiccups. Other things your doctor may ask about include whether you've ever:

• Had heart disease
• Smoked
• Traveled to places where you may have been exposed to tuberculosis
• Had a job that exposed you to asbestos

Physical Exam

Your doctor will listen to your breathing with a stethoscope and tap lightly on your chest. If you have a pleural effusion, your breathing may sound muffled. There also may be a dull sound when your doctor taps on your chest.

Diagnostic Tests

Your doctor may use one or more of the following tests to diagnose a pleural effusion.

• Chest x ray. This test takes pictures of your heart and lungs. It may show air or fluid in the pleural space. It also may show what's causing the pleural effusion, such as pneumonia or a lung tumor. To get more detailed pictures, the x rays may be done while you're in different positions.
• Ultrasound. This test uses sound waves to create pictures of your lungs. It may show where fluid is in your chest. Sometimes it's used to find the right place to insert the needle or tube for thoracentesis.
• Computed tomography (CT) scan. This test provides a computer-generated picture of the lungs that can show pockets of fluid. It may show fluid when a chest x ray doesn't. It also may show signs of pneumonia or a tumor.