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 needle (and sometimes a plastic catheter) inserted through the chest wall. Ultrasound pictures are often used to guide the placement of the needle. 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 hard to breathe. Fluid inside the pleural space may be found during a physical examination and is usually confirmed by a chest X-ray.
How is a thoracentesis done?
This procedure may be done in your doctor's office, in the X-ray department of a hospital, in an emergency room, or at your bedside in the hospital.
You will need to take off all or most of your clothes (you may be allowed to keep on your underwear if it does not interfere with the procedure). You will be given a cloth or paper covering to use during the procedure. During the procedure, you will be seated but leaning forward on a padded bedside table. If your test is done in the X-ray department, X-rays or an ultrasound may be used to locate the fluid in your chest.
The needle site between your ribs will be cleaned with an antiseptic solution. Your doctor will give you a local anesthetic in your chest wall so you won't feel any pain when the longer needle that withdraws the fluid is inserted. When the area is numb, your doctor will insert the needle to where the fluid has collected (pleural space). You may feel some mild pain or pressure as the needle enters the pleural space.
Your doctor will use a syringe to remove a sample of fluid. If larger amounts of pleural fluid are removed, a small tube attached to a vacuum bottle is used. Your doctor will send the fluid to the lab. After the fluid is removed, the needle or small tube is removed. Then a bandage is put on the site.
An X-ray may be taken right after the procedure to make sure that no complications have occurred.
What are the risks of a thoracentesis?
Thoracentesis is generally a safe procedure. A chest X-ray may be done right after the procedure to make sure that no complications have occurred. Complications may include:
- A partial collapse of the lung (pneumothorax).
- Fluid buildup in the lung.
- Damage to another organ, such as the liver or spleen.