Thoracentesis

What is Thoracentesis?

Thoracentesis is a procedure to remove fluid fom the space between the lungs and the chest wall called the pleural space. Normally, very little fluid is present in this space. An accumulation of excess fluid between the layers of the pleura is called a pleural effusion.

It is done with a needle or a catheter inserted through the chest wall. The pleural fluid may be sent to a lab to determine what may be causing the fluid to accumulate in the pleural space. Sometimes the excess fluid is removed to relieve shortness of breath and pain caused by a pleural effusion.

How to prepare for the procedure?

A consent form needs to be signed before the procedure. Talk to your doctor about any concerns you have regarding the need for the procedure, its risks, how it will be done, or what the results will indicate.

Before the procedure, tell your doctor:

• If you are taking any medicines, including prescription and over-the-counter medicines
• About any allergies to medicines or latex.
• About any previous bleeding problems or if you are taking blood-thinners, such as aspirin, clopidogrel (Plavix), or warfarin (Coumadin).
• If you are or might be pregnant.
• If you have had lung surgery, since scarring from the first procedure may make it difficult to do this procedure.

Your doctor may order some tests before the procedure such as:

• Complete blood count (CBC)
• Bleeding factors
• Chest X-ray

How is thoracentesis done?

Ultrasound machines are used routinely to increase the safety of the procedure.

You will sit on the edge of a chair or bed with your head and arms resting on a table. Usually, you are asked to sit upright during the procedure. It is important to remain still during the procedure so that the fluid does not shift.

The skin around the procedure site is disinfected. A small amount of numbing medicine (a local anesthetic) is injected into the area. This medicine helps minimize discomfort during the procedure.

The thoracentesis needle is inserted above the rib into the pleural space. A syringe is attached to this needle and is used to withdraw fluid from around the lung. 

The fluid removed during thoracentesis will be sent to the lab for analysis.

What to expect after the procedure?

After the procedure the insertion site is observed for signs of bleeding.

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

What complications are likely to occur due to the procedure?

Thoracentesis is generally a safe procedure. Complications may include:

• Pain or discomfort during insertion of the needle.
• Bleeding can occur during insertion of the needle; this is usually minor and stops on its own.
• Infection at the site of insertion.
• Pneumothorax or lung collapse if the needle punctures the lung.
• Pulmonary edema if large amount of fluid is removed.