Thoracentesis

Illustration showing a person having thoracentesis.

Thoracentesis is a procedure to remove excess fluid in the space between the lungs and the chest wall. This space is called the pleural space. When fluid builds up in the pleural space, it's called a pleural effusion, or, if infection is present, an empyema. If a lot of fluid is present, breathing may become difficult. Thoracentesis is done to help find the cause of the extra fluid, and it may be used to make breathing easier.

Other Names

• Thoracocentesis
• Pleural tap
• Pleural aspiration

Why Thoracentesis is Done

Normally, the pleural space is filled with a small amount of fluid, but some conditions, such as heart failure, lung infections, and tumors, can cause fluid to accumulate in this space. This is called a pleural effusion or an empyema. This fluid can press on the lungs, making it difficult to breathe. However, thoracentesis is not needed in all cases. A thoracentesis can uncover the cause of a pleural effusion or empyema. Once the cause is identified, appropriate treatments can be initiated to alleviate the fluid buildup. In some cases, the procedure can be used to remove fluid and improve breathing immediately.

Preparation

No special preparations are needed before thoracentesis.

How Thoracentesis is Done

During thoracentesis, a doctor inserts a needle or tube between the ribs and into the pleural space. The doctor may use an ultrasound scanner to identify the correct place to drain the fluid, or may look at the patient's chest x-ray or CT scan. Before starting the procedure, the insertion site is cleaned and a medication is injected to numb the area. Sometimes the needle or tube causes pressure or discomfort. Excess fluid is then drawn up into the needle or tube. This sometimes causes pain or an urge to cough. When enough fluid is removed, the instrument is removed, and a small bandage is placed on the site where the instrument had been inserted.

The illustration shows a person having thoracentesis. The person sits upright and leans on a table. Excess fluid from the pleural space is drained into a bag.

Usually, only the amount of fluid needed to find the cause of the pleural effusion is removed. However if a lot of fluid is present, more may be removed. By removing large amounts of fluid, the lungs are allowed to expand more and breathing is made easier.

The procedure, including preparation, usually takes about 15 to 20 minutes, but the needle is in the chest for only a few minutes. It may take longer if a lot of fluid has collected in the space.

The fluid removed from the chest is sent for laboratory testing. Once the cause of the pleural effusion is known, appropriate treatments can be started. For example, antibiotics are often prescribed if the fluid accumulation had been caused by an infection.

Benefits

A thoracentesis has two benefits:

• Diagnosis: identifying the cause of the pleural effusion by analyzing the fluid that is removed
• Treatment: Relieving symptoms due to the pleural effusion, such as difficulty breathing

Risks

Complications are uncommon with thoracentesis. Potential complications include the following:

• Pain
• Pneumothorax
  • Sometimes air comes in through the needle, or the needle makes a hole in a lung. Usually, a hole seals itself. If enough air gets into the pleural space, however, the lung may collapse (pneumothorax). In this case, a tube is inserted into the chest to remove the air and allow the lungs to expand.
• Shortness of breath
• Cough
• Fainting (vasovagal reaction)
• Bleeding and hematoma
  • Bleeding can occur in or around the lungs. A tube inserted into the chest is used to remove the blood. Surgery may be needed in severe cases.
• Re-expansion pulmonary edema^[1]

In extremely rare cases, the liver or spleen may be damaged.

Expected Outcomes

Follow-up procedures

Often a Chest X-ray is taken following thoracentesis to check the status of the lungs.

Alternatives

Depending on the amount of fluid around the lungs, other treatments may be used. Observation (waiting for the body to reabsorb the fluid on its own), repeated drainage using thoracentesis, placement of a chest tube, and surgical drainage are all options for the management of these conditions.^[2][3]

Experts on Thoracentesis

• A pulmonologist is a medical doctor who is an internal medicine specialist with advanced training in the treatment of diseases of the respiratory system.

History

Thoracentesis was first described in 1852.^[4]

References

1. ↑ Jones PW, Moyers JP, Rogers JT, Rodriguez RM, Lee YC, Light RW. Ultrasound-guided thoracentesis: is it a safer method? Chest. 2003 Feb;123(2):418-23. Abstract | Full Text
2. ↑ Cheng G, Vintch JR. A retrospective analysis of the management of parapneumonic empyemas in a county teaching facility from 1992 to 2004. Chest. 2005 Nov;128(5):3284-90. Abstract | Full Text
3. ↑ Light RW. Parapneumonic effusions and empyema. Proc Am Thorac Soc. 2006;3(1):75-80. Abstract | Full Text
4. ↑ Wikipedia. Thoracentesis.

External Links

National Heart, Lung, and Blood Institute: Pleurisy and Other Disorders of the Pleura