What is Thoracentesis?

Thoracentesis is a procedure that removes extra fluid from the space between the lung and the chest wall. That space is called the pleural space, and the fluid buildup is called a pleural effusion. A thin needle, then a small catheter, is passed between the ribs into the fluid, usually with ultrasound guidance.

A small sample may be taken for testing. This is a diagnostic thoracentesis. A larger amount may be drained to help you breathe. This is a therapeutic thoracentesis. The catheter is removed when drainage is finished. It is not a chest tube that stays in place, unless your team places a separate drain for infection.

Why Do I Need It?

Pleural fluid can come from heart failure, infection, cancer, inflammation, liver or kidney disease, or other causes. Extra fluid can cause:

• Shortness of breath, especially with activity or when lying down
• Chest tightness, cough, or pain with a deep breath
• The need to test the fluid for infection, cancer cells, or the cause of the buildup
• Draining fluid can make breathing easier while the cause is treated

How Do I Prepare?

• Medicines: Tell the team about blood thinners, antiplatelet drugs, and all other medicines. Some may be held. Do not stop them unless you are told to.
• Allergies: Report allergies to local anesthetic, latex, iodine, or adhesives.
• Imaging: A chest ultrasound, and sometimes a chest X-ray or CT, shows where the fluid is and how much is present.
• Eating and cough: You can often eat and drink unless told otherwise. Tell the team if you have a cough you cannot control.
• Support: Arrange a ride if sedation is planned. Most thoracentesis procedures use only local anesthetic.

How is it Performed?

• You usually sit on the edge of the bed and lean forward, with your arms on a table. Some people lie on their side.
• Ultrasound marks a safe spot between the ribs, above a rib, so the needle avoids the nerve and blood vessels that run under each rib.
• The skin is cleaned and numbed. You may feel pressure, but sharp pain should be brief.
• A needle, then a thin catheter, enters the fluid. Fluid drains into a bag or bottle. Stay still and breathe as directed. Coughing during drainage is common.
• The catheter is removed, and a bandage is placed. Staff will watch you for a short time. A chest X-ray is done if there is concern for a collapsed lung.

Care Instructions

• Keep the bandage clean and dry for about 24 hours, then you may usually shower and pat the site dry.
• Mild soreness at the site is common. Coughing for up to an hour after fluid removal can be normal as the lung re-expands.
• Rest the day of the procedure. Avoid heavy lifting and strenuous activity for 24 to 48 hours.
• You may breathe more easily. Fluid can return, so follow the plan for the cause of the effusion.
• Take pain medicine only as directed. Ask when to restart any blood thinners.

What to Watch Out For

Contact your care team promptly, or seek emergency care for severe symptoms, if you notice:

• Increasing shortness of breath, chest pain, or a feeling that one side of the chest is not expanding
• Coughing up blood
• Dizziness, fainting, or a racing heartbeat
• Bleeding that soaks the bandage
• Fever, chills, or increasing redness, warmth, or drainage at the site
• These can be signs of a collapsed lung (pneumothorax), bleeding, or infection