What is Thoracentesis & How is it Performed?

Thoracentesis, also known as pleural tap, is a procedure that is performed to remove excess air and fluid from the pleural space. Pleural space is a small space between the lungs and the rib cage. It normally also contains a small amount of fluid in this space. Fluid build-up in this space is known as pleural effusion and it can compress the lungs and cause difficulty in breathing.

A few conditions that can lead to pleural effusion are:

What is Thoracentesis?

Thoracentesis is a procedure that is minimally invasive. It involves inserting a needle to remove excess fluid from the pleural space. The purpose of draining the fluid is to make it easier to breathe. Sometimes it also helps in determining the cause of fluid buildup.

According to the National Heart, Lung, and Blood Institute, it takes 10-15 minutes or longer to drain fluid from the lungs. It can also take longer than this depending on the amount of fluid in the pleural space.(1)

Pleural fluid analysis can be performed after thoracentesis to know the cause of fluid build-up. A pleural biopsy can also help determine the cause.

Thoracentesis Procedure: How is it Performed?

Thoracentesis is performed in a doctor’s office or in a hospital and is mostly done in sedation.

The patient after sitting on a chair or lying on the table is positioned in a way a doctor can get access to the pleural space. An ultrasound is used to confirm the correct area where the needle goes into. In some cases, it is also done under CT guidance.

The area selected is cleaned and injected with a numbing agent. The needle is inserted in between the ribs into the pleural space. It makes the patient a bit uncomfortable but has to keep still. The fluid is then drained out.

Once the fluid is drained out, the insertion site is closed with a bandage. An x-ray is performed after the procedure.

Depending on the severity of the symptoms, the patient is asked to stay in a hospital overnight or is discharged home. The patient is allowed to go home after monitoring the blood pressure, breathing rate, oxygen saturation, and pulse.

Who Needs Thoracentesis?

Thoracentesis is performed in people who have pleural effusion and in those who need a diagnosis for a certain condition. According to the American Thoracic Society, thoracentesis is performed due to following reasons:

  • To diagnose the reason behind pleural effusion
  • To diagnose any suspected infection
  • To diagnose cancer or to improve symptoms
  • To ease the symptoms of pleural effusion

A doctor can help determine if a person is a good candidate for pleural effusion.

People who have less pleural fluid or those who have an infection or wound at the needle insertion site are not good candidates for pleural effusion.

A doctor needs to be cautious while performing thoracentesis in the following people:

  • Who are on blood thinners
  • Having bleeding disorders
  • Have scarring from recent lung surgery
  • Suffering from other conditions where potential complications outweigh the benefits

Before going ahead with the thoracentesis procedure it is important to inform the doctor if taking medications like blood thinners, allergic to any medication, pregnant, having any bleeding problem, having scarring from previous procedures, and currently having lung disease like asthma or emphysema.

Risk Associated with Thoracentesis

The risk associated with thoracentesis include:

  • Pain
  • Bleeding
  • Bruising
  • Infection
  • Air accumulation

The most common complication include liver and spleen injury.(1) These are rare nowadays as x-ray and CT are used during the thoracentesis procedure.

A study performed in 2020 found, while using imaging the risk of complication was 1.2 percent. Comparatively, there was a 10-18 percent risk of collapsed lungs when undergoing thoracentesis without imaging.(2)

Make sure to contact the doctor if after the procedure you develop the following symptoms:

Thoracentesis is a rather simple procedure to remove fluid from the pleural space. Also, it is not a suitable option for all. Before going ahead it is important to discuss the risk and benefits with a doctor.