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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.

Need to Know

Nice to Know
  • You will be asked to sign a consent form before the procedure is performed
  • Tell your radiologist about any allergies, especially to local or general anesthetics and contrast materials (“x-ray dye”)
  • If you are taking a blood thinner or aspirin product, the physician will instruct you when to stop taking these medications
  • Inform your radiologist if you are pregnant
  • Wear comfortable, loose-fitting clothing
  • You can request a gown to wear during your treatment
  • You can go home after the procedure if vitals are stable
  • Most patients feel minimal discomfort after the procedure


How Does It Work?

This procedure may be done in your doctor's office, an emergency room, the ultrasound department, or at your bedside in the hospital. You will need to take off the top off your clothing. You will be given a gown to use during the procedure. You will be asked to sign a consent form before a thoracentesis.

What Happens — Before, During, and After?

A clinical staff member will bring you into the procedure area. Your doctor or mid-level provider will greet you, review the procedure, and answer any questions you may have. During the procedure, you will be seated but leaning forward on a padded bedside table. Ultrasound will be used to confirm the location of fluid in your chest. The needle site between your ribs will be cleaned with an antiseptic solution. Your doctor or mid-level provider 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. Once the area is numb, your doctor or mid-level provider 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. A syringe or a small tube attached to a vacuum bottle is used to remove the pleural fluid. A large amount of fluid can be removed if the fluid is making it difficult for you to breathe. Once the fluid is removed, the needle or small tube is removed and a bandage is put on the site.

An X-ray is usually taken right after the procedure to make sure that no complications have occurred. If more pleural fluid collects and needs to be removed, another thoracentesis may be done later.

This procedure takes about 10 to 15 minutes.

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How Should I Prepare?

There are things you can do to make your experience more comfortable, and many of these will depend on your individual preferences. You might like to keep a list of questions or – as you’re doing now- educate yourself about the procedure.

Another important part of your preparation will be guided by your doctor:

  • Your doctor may ask you to stop taking aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or blood thinners (such as Coumadin, Warfarin, Plavix, Fragmin) for a time before the procedure.

Some of your preparation will need to be timed to the procedure:

  • The day before the procedure (or the Friday before, if you’re scheduled for a Monday procedure), a clinical staff member from the Interventional Radiology Department will call you. The clinical staff member will give you any additional instructions, and will ask if you have any questions.
  • Take your medications as instructed
  • When you arrive, make sure the clinical staff member and radiologist know about any allergies you may have, especially allergies to local anesthetics (such as lidocaine), general anesthetics, or x-ray dye (contrast media). If there’s any chance you might be pregnant, tell your radiologist.
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What Should I Bring?

  • Wear comfortable, loose-fitting clothes
  • Wear comfortable shoes
  • Avoid bringing jewelry or valuables
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What Are the Benefits and Risks?

Thoracentesis is generally a safe procedure. A chest X-ray is usually done right after the procedure to make sure that no complications have occurred.

The benefits of Thoracentesis could be:

  • Diagnose an infection in the pleural cavity
  • Remove a large amount of fluid that is causing pain or difficulty breathing

Risks you should be aware of include:

  • You can sustain a partial collapse or complete collapse of the lung (pneumothorax)
  • You can experience pulmonary edema, which may occur if a large amount of fluid is removed
  • There is always a small chance of bleeding and infection

Keep in mind that this information is general. Your radiologist is the best source of information about how these risks and benefits may apply to you.


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