Treatment may be directed at removing the fluid, preventing its re-accumulation, or addressing the underlying cause of the fluid buildup.

Therapeutic thoracentesis may be done if the fluid collection is large and causing pressure or shortness of breath. Treatment of the underlying cause of the effusion then becomes the goal.

For example, pleural effusions caused by congestive heart failure are treated with diuretics and other medications that treat heart failure. Pleural effusions caused by infection are treated with antibiotics specific to the causative organism. In patients with cancer or infections, the effusion is often treated by using a chest tube to drain the fluid. Chemotherapy, radiation therapy, or instilling medication within the chest that prevents re-accumulation of fluid after drainage may be used in some cases.

• A lung surrounded by a fluid collection for a long time can collapse.
• Pleural fluid that becomes infected can become an abcess, called an empyema, that requires prolonged drainage with a catheter, called a chest tube, that is placed into the fluid collection.
• Pneumothorax (air within the chest cavity) can be a complication of the thoracentesis procedure.

Call your health care provider if symptoms suggestive of pleural effusion develop.

Call your health care provider or go to the emergency room if shortness of breath or difficulty breathing occurs immediately after thoracentesis.