What is a Thoracentesis?

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 plastic catheter inserted through the chest wall. 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 difficult to breathe. Fluid inside the pleural space may be found during a physical examination and is usually confirmed by a chest X-ray.