Pleural effusion

  • Definition
    • A pleural effusion is a buildup of fluid between the layers of tissue that line the lungs and chest cavity.

  • Alternative Names
    • Fluid in the chest; Fluid on the lung; Pleural fluid

  • Causes
    • Your body produces pleural fluid in small amounts to lubricate the surfaces of the pleura. This is the thin tissue that lines the chest cavity and surrounds the lungs. Pleural effusion is an abnormal, excessive collection of this fluid.

      There are two types:

      • Transudative pleural effusion is caused by fluid leaking into the pleural space. This is from increased pressure in the blood vessels or a low blood protein count. Congestive heart failure is the most common cause.
      • Exudative effusion is caused by blocked blood vessels or lymph vessels, inflammation, lung injury, and tumors.
  • Symptoms
  • Exams and Tests
    • Your doctor will examine you and listen to your lungs with a stethoscope.

      The following tests may help to confirm a diagnosis:

      • Chest x-ray
      • Kidney and liver function blood tests
      • Pleural fluid analysis (examining the fluid under a microscope to look for bacteria, cancer cells, and protein level)
      • Thoracentesis (a sample of fluid is removed with a needle inserted between the ribs)
      • Ultrasound of the chest and heart
  • Treatment
    • The goal of treatment is to:

      • Remove the fluid
      • Prevent fluid from building up again
      • Determine and treat the cause of the fluid buildup

      Removing the fluid (thoracentesis) may be done if there is a lot of fluid and it is causing chest pressure, shortness of breath, or other breathing problems, such as a low oxygen level. Removing the fluid allows the lung to expand, making breathing easier.

      The cause of the fluid buildup must also be treated.

      If it is due to congestive heart failure, you may receive diuretics (water pills) and other medications to treat heart failure.

      Pleural effusion caused by infection is treated with antibiotics.

      In people with cancer or infection, the effusion is often treated by using a chest tube for several days to drain the fluid.

      Sometimes, small tubes can be left in the pleural cavity for a long time to drain the fluid. In some cases, the following may be done:

  • Outlook (Prognosis)
    • The outcome depends on the underlying disease.

  • Possible Complications
    • Complications may include:

      • Lung damage
      • Infection that turns into an abscess, called an empyema, which will need to be drained with a chest tube
      • Air in the chest cavity (pneumothorax) after thoracentesis
  • When to Contact a Medical Professional
    • Call your doctor if you have symptoms of pleural effusion.

      Call your doctor or go to the emergency room if shortness of breath or difficulty breathing occurs right after thoracentesis.

  • References
    • Broaddus C, Light RW. Pleural effusion. In: Mason RJ, Broaddus CV, Martin TR, et al, eds. Textbook of Respiratory Medicine. 5th ed. Philadelphia, PA: Saunders Elsevier; 2010:chap 73.

      Celli BR. Diseases of the diaphragm, chest wall, pleura, and mediastinum. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 99.