What is thoracentesis?
Thoracentesis is a bedside medical procedure used to drain fluid from the space between your chest wall and lungs (the pleural cavity).
Your lungs are enclosed in a two-layered covering called the pleura. There is a thin space between the two layers of the pleura called the pleural space that contains a small amount of fluid called the pleural fluid. Some disease conditions may lead to fluid collection in the pleural space (pleural effusion), which may prevent the normal expansion of the lungs causing several symptoms such as difficulty in breathing.
Thoracentesis is a minimally invasive procedure, which means it does not involve any major surgical cuts or incisions, and is typically performed under local anesthesia. During the procedure, the doctor inserts a needle under image guidance between your ribs to withdraw fluid from the pleural cavity (pleural effusion).
Removing the excess fluid provides relief from the associated symptoms such as shortness of breath and chest discomfort. The fluid is then sent for lab analysis to understand the cause of the effusion.
When is thoracentesis performed?
Thoracentesis is performed when the pleural fluid gets collected in the chest (pleural effusion) and your doctor wants to determine the reason for it besides reducing your symptoms due to the effusion. Common conditions for which thoracentesis may be performed are as follows:
- Pleural effusion associated with congestive heart failure (a condition in which the heart does not properly pump out blood to the body)
- Empyema (an area of pus in the pleural space that is the space between the two layers of the pleura)
- Pulmonary embolism (blood clot in the lungs)
- Cancer
- Pulmonary hypertension (high blood pressure in the blood vessels in the lungs)
- Pneumonia
- Liver failure
- Tuberculosis
- Infections (viral, fungal, or bacterial)
- Reactions to medicines
Is thoracentesis painful?
Your doctor will ensure that you feel minimal pain and discomfort during the procedure by giving local anesthesia. You may feel some pain in the area where the needle is inserted. This may happen toward the end of the procedure and should go away when the procedure is finished.
Usually, the discomfort is transient, and medication is not required for it. If you feel a lot of pain, you must tell your doctor, and they may pause the procedure.
How much fluid can be drained during thoracentesis?
The amount of fluid removed during thoracentesis varies. For instance, if thoracentesis is performed as a diagnostic procedure, then 20-100 mL of fluid may be removed. For therapeutic purposes, removing 400-500 mL of the pleural fluid is often sufficient to reduce shortness of breath. The usual recommended limit is 1000-1500 mL in a single thoracentesis procedure.
What are the risks of thoracentesis?
Thoracentesis is generally a safe procedure. It does not involve any surgical incisions. The complication of thoracentesis may vary depending on the general health and other factors. Your healthcare provider will guide you before the procedure about the risks most applicable to you. The usual risks of thoracentesis include:
- Pneumothorax (presence of air in the space between the lungs and chest wall causing the lungs to collapse)
- Bleeding
- Infection
- Pain
- Pulmonary edema or wet lungs (presence of excessive fluid in the lungs)
- Breathing difficulty
- Liver injury
- Spleen injury