What is it?
A thoracentesis is a procedure that removes fluid from the pleural space. The pleural space is the space between the lungs and the chest wall. It is normal to have a small amount of fluid in this space (about four teaspoons). An excess of pleural fluid is called a plueral effusion. As the amount of fluid increases, it becomes difficult to breathe since the fluid causes increased pressure on the lungs.
There are two reasons that a thoracentesis will be performed. These are:
- Diagnostic: in this case, the fluid is sent to a lab to determine the cause of the pleural effusion. Pleural effusions can be caused by cancer, heart failure, pulmonary embolism (blood clot in the lungs), infection, sarcoidosis, and reactions to certain medications.
- Therapeutic: in this case, the procedure is done to relieve the symptoms and discomfort caused by the pleural effusion. In this scenario, the cause of the pleural effusion has likely already been determined.
A pleural effusion is diagnosed based on your medical history, your physical exam and diagnostic testing. Symptoms can include new or worsening shortness of breath and coughing. Medical history that can be associated with pleural effusion include having a history of smoking, heart disease, cancer, or exposure to tuberculosis or asbestos. When your provider listens to your lungs, they may sound muffled or have areas where no breaths can be heard. You may have an x-ray, ultrasound, or CT scan of your chest, all of which will show a buildup of fluid.
Once your thoracentesis is complete and the fluid has been tested (if necessary), your provider will notify you of the follow-up plan and further treatment options. If it is determined that the excess fluid will continue to accumulate, your provider may suggest that a catheter be inserted to allow the fluid to be drained regularly. Speak with your provider regarding any concerns regarding your plan of care.
How is it done?
A thoracentesis can be done either in a provider’s office or in the hospital. Your provider will explain the procedure to you and have you sign a consent form. Notify your provider of any medications you are taking, any bleeding disorders you have, any allergies, or if you may be pregnant.
The procedure can take anywhere from 10 minutes up to 45 minutes, depending upon the amount of fluid being removed. You will be awake for the procedure and the amount of discomfort you experience should be minimal. You may be asked to put on a hospital gown. You may be given pain and/or anti-anxiety medications prior to the procedure if needed. You will want to use the bathroom prior to the procedure starting since you won’t be able to move once the procedure starts.
- First, your provider will have you sit at the edge of a chair, exam table or hospital bed with your arms resting on a table in front of you at about the height of your chest. Your legs may be supported with a chair under your feet and a pillow may be placed on the table to put your arms and head on to make you more comfortable. If you are unable to stay in this position you may be able to have the procedure done while lying on your side.
- Once you are in a comfortable position your provider will ask you to not move, take deep breaths or cough. The provider may palpate (feel with his or her hands) the spaces between your ribs on your back. An ultrasound may be used to find the space where the fluid is most accessible. A cool or warm gel will be placed on the ultrasound probe and you may feel slight pressure where the ultrasound is being placed on your skin. This is not painful.
- Once the provider determines the best insertion site for the needle that will remove the fluid they will mark the spot. Next, the provider will clean the area where the needle will be inserted. This will most likely feel cold. A sterile drape may be placed surrounding the area of the insertion site.
- The area around the site where the needle will be placed is then numbed. A small needle will be used to inject the local anesthetic (numbing medication) below the skin. The medication may cause a brief burning or stinging sensation. Your provider will wait a few moments to ensure the area is properly numbed.
- Once the area is appropriately numb, your provider will insert a needle between your ribs and into the pleural space. It may be uncomfortable and you may feel some pressure, but it should not be painful.
- The fluid will drain through the needle, or a tube connected to the needle, into a container, test tube, or large glass container may be used. The needle or tube will stay in as long as it takes to drain the amount of fluid necessary either for testing or to relieve symptoms. While the fluid is draining you may feel the need to cough or you may feel some chest pain. Notify your provider if you are experiencing any discomfort.
- Once the fluid is removed, the needle or tube will be removed and a small bandage will be placed at the insertion site. You are now able to move around as you feel able.
- A chest x-ray is usually performed shortly after the thoracentesis is complete to monitor for any complications. Your blood pressure, breathing, and oxygenation will be monitored for a period of time after the procedure. If your thoracentesis was done in your doctor’s office you will be sent home once you are stable. You should have someone drive you home.
What are the risks?
As with any procedure there are risks associated with having a thoracentesis. These risks include pneumothorax (collapsed lung), respiratory distress, pain, bleeding, infection, and bruising.
A pneumothorax is a side effect where air collects in the pleural space. The air can be introduced into the pleural space through the needle used to remove the fluid, or the needle may puncture the lung allowing air to enter the space. In most cases, a hole in the lung will seal itself, but if enough air gets into the pleural space the lung can collapse. If the lung collapses, a tube placed in the chest may be needed to remove the air.
You may also experience pain, bleeding, infection, and bruising at the insertion site of the needle. Pain may be managed with medication and changes in your positioning. It is important to keep the site clean and dry until healed. Bleeding at the insertion site will be managed by applying pressure. It is rare for bleeding to occur in or around the lungs, but if this happens your provider may need to place a tube in your chest to drain this blood. If the area appears infected (redness, tender or sore, pus or drainage), notify your provider. Infection can be treated with antibiotics.
When to contact your care team
It is important to contact your care team with any changes after your thoracentesis including fever, new or worsening shortness of breath, chest pain, uncontrollable pain or bleeding, foul smelling discharge, or redness and warmth at the insertion site.