Empyema is also called pyothorax or purulent pleuritis. It’s a condition in which pus gathers in the area between the lungs and the inner surface of the chest wall. This area is known as the pleural space. Pus is a fluid that’s filled with immune cells, dead cells, and bacteria. Pus in the pleural space can’t be coughed out. Instead, it needs to be drained by a needle or surgery.
What causes empyema?
Empyema can develop after you have pneumonia. Many different types of bacteria may cause pneumonia, but the two most common are Streptococcus pneumoniae and Staphylococcus aureus. Occasionally, empyema may happen after you’ve had surgery on your chest. Medical instruments can transfer bacteria into your pleural cavity.
The pleural space naturally has some fluid, but infection can cause fluid to build up faster than it can be absorbed. The fluid then becomes infected with the bacteria that caused the pneumonia or infection. The infected fluid thickens. It can cause the lining of your lungs and chest cavity to stick together and form pockets. This is called an empyema. Your lungs may not be able to inflate completely, which can lead to breathing difficulties.
What conditions put you at risk?
The biggest risk factor for empyema is having pneumonia. Empyema occurs most frequently in children and older adults. However, it’s fairly uncommon. In one study, it occurred in less than 1 percent of children with pneumonia.
Having the following conditions can also increase your chances of empyema after pneumonia:
- chronic obstructive pulmonary disease (COPD)
- rheumatoid arthritis
- a weakened immune system
- surgery or recent trauma
- lung abscess
How is empyema diagnosed?
A doctor may suspect empyema if you have pneumonia that isn’t responding to treatment. Your doctor will take a complete medical history and physical examination. They may use a stethoscope to listen for any abnormal sounds in your lungs. Your doctor will usually perform certain tests or procedures to confirm a diagnosis:
- Chest X-rays and CT scans will show whether or not there’s fluid in the pleural space.
- An ultrasound of the chest will show the amount of fluid and its exact location.
- Blood tests can help check your white blood cell count, look for the C-reactive protein, and identify the bacteria causing the infection. White cell count can be elevated when you have an infection.
- During a thoracentesis, a needle is inserted through the back of your ribcage into the pleural space to take a sample of fluid. The fluid is then analyzed under a microscope to look for bacteria, protein, and other cells.
How is empyema treated?
Treatment is aimed at removing the pus and fluid from the pleura and treating the infection. Antibiotics are used to treat the underlying infection. The specific type of antibiotic depends on what type of bacteria is causing the infection.
The method used to drain the pus depends on the stage of the empyema.
In simple cases, a needle can be inserted into the pleural space to drain the fluid. This is called percutaneous thoracentesis.
In the later stages, or complex empyema, a drainage tube must be used to drain the pus. This procedure is usually performed under anesthesia in an operating room. There are different types of surgery for this:
- Thoracostomy: In this procedure, your doctor will insert a plastic tube into your chest between two ribs. Then they’ll connect the tube to a suction device and remove the fluid. They may also inject medication to help drain the fluid.
- Video-assisted thoracic surgery: Your surgeon will remove the affected tissue around your lung and then insert a drainage tube or use medication to remove the fluid. They will create three small incisions and use a tiny camera called a thoracoscope for this process.
- Open decortication: In this surgery, your surgeon will peel away the pleural peel.