What is Thoracentesis Really Like?

Your provider may have told you that you need a thoracentesis and you are probably wondering what thoracentesis is, why you need it, and the details about what to expect.

What is thoracentesis?

Thoracentesis is a procedure that removes extra fluid from around your lungs. It is normal to have fluid in the layer around your lungs. Too much fluid causes problems and makes it harder to breathe.

During the procedure, your doctor will numb an area on your chest and use a needle and a thin tube to remove the fluid. The fluid can then be tested to see why the extra fluid buildup happened and will help decide what (if any) additional treatment is needed.1

Why do I need a thoracentesis?

Fluid can build up from lung cancer or can be caused from other conditions. This fluid buildup is called a pleural effusion. Thoracentesis can be performed to relieve the symptoms of this extra fluid and it can be performed to find the reason for the buildup.

How will I prepare for the procedure?

Your doctor will order a chest X-ray or ultrasound to get an exact view of the fluid and where it is located. Your doctor will go over everything so that you know the steps and what to expect. Any questions you have can and will be answered.

You may have to stop taking some of your regular medications before the procedure, depending on your doctor’s instruction. Rest assured, thoracentesis is a common procedure that is routinely performed.1,2

What are the steps of thoracentesis?

Positioning and cleaning

You will be placed in a sitting position in a hospital bed. Your arms will rest on a bedside table, which helps open up the spaces in between the ribs, where the doctor will insert the needle and catheter. If you can not sit up, you can lie on your side.

Your blood pressure, pulse, and heart rate will be watched and recorded. The area of the procedure will be cleaned with a solution to prevent infection.1,2


The doctor will numb the site of the procedure using a medication that is injected into the area using a small needle. This helps to decrease pain during the procedure.1,2

Fluid removal

Once numb, the doctor will insert a needle between your ribs in your back into the space where the extra fluid is. A thin, straw-like plastic tube will then be inserted to replace the needle. Because your skin was numbed, you should only feel pressure or a pushing sensation. The plastic tube connects to a drainage container or syringe and the fluid that is removed will fill this container. When enough fluid is drained, this tube will be removed and a bandage will be placed over the site.

You may have another chest X-ray after the procedure to make sure all the fluid was removed and that your lungs are working properly.1,2

What are the possible complications?

Thoracentesis is a common procedure. Most times, the procedure is done without complications. On occasion, complications may occur including:1

  • Pain: You may have some discomfort with the needle insertion. The numbing medicine helps with this.
  • Minor bleeding: Sometimes a blood vessel might be injured during the procedure.
  • Collapsed lung: The needle may poke a hole in the lining of the lung. This causes air to build up around the lung, making it collapse. This needs to be treated with a tube inserted into the chest to relieve this air.
  • Infection: Cleaning the site decreases this chance, but infection can happen on occasion.
  • Excess fluid in the lung: Rarely, the procedure can cause a sudden collection of fluid in the lung that usually resolves on its own.
  • Liver or spleen injury: Also rare, the liver or spleen may be injured during the procedure by accidental puncture.

What follow up will I need?

Depending on the amount of fluid and the reason why the fluid built up, you may or may not need follow up. Follow your doctor’s teaching about this and keep any appointments you have with your doctor.

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