Empyema

About empyema

The term 'empyema' is most commonly used to refer to pus-filled pockets that develop in the pleural space. This is the slim space between the outside of the lungs and the inside of the chest cavity.

Although it can occasionally be life-threatening, it's not a common condition. Most bacterial infections are effectively treated with antibiotics before they get to this stage. 

Symptoms

An empyema can be distressing and uncomfortable, causing:

• a fever and night sweats
• a lack of energy
• difficulty breathing
• weight loss
• chest pain
• a cough - which can involve coughing up mucus containing pus 

Causes of empyema

The lungs and inside of the chest cavity are lined with a smooth layer called the pleura. These layers are separated by a thin space – the pleural space. This is filled with a small amount of fluid called pleural fluid.

The pleural fluid can sometimes build up and become infected, so that a collection of pus forms. This can thicken and cause areas of the pleura to stick together, creating pockets of pus.

Empyema can worsen to become many more pockets of pus, with thick deposits coating the outer layer of the lungs. These deposits prevent the lungs expanding properly.

Pneumonia and other possible causes

The most common cause of empyema is pneumonia caused by a bacterial infection of the lungs. An empyema can form when a person with pneumonia fails to fully get better with treatment.

Other possible causes are:

• bronchiectasis, a long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of mucus that can make the lungs more vulnerable to infection
• a blood clot or other blockage preventing blood flow to the lungs, causing some of the lung tissue to die - this is known as a pulmonary infarction
• surgery to the chest (empyema is a rare complication)
• an endoscopy (empyema is a rare complication)
• a serious injury to the chest
• an infection elsewhere in the body that has spread via the bloodstream
• an infection caused by inhaled food, if you have swallowing problems (but this is rare)
• tuberculosis (this is rare in Northern Ireland)

You're more at risk of developing an empyema if you:

• have diabetes
• have a weakened immune system
• have acid reflux
• drink too much alcohol or take a lot of recreational drugs

Both adults and children can be affected.

Diagnosing empyema

An empyema is usually suspected when a person with severe pneumonia does not improve with treatment and they start to show some of the symptoms.

If the patient is coughing up mucus, a sample of this should be taken to be inspected. The type of bacteria causing the infection is identified, so the right antibiotics can be given.

A blood sample will also be taken, to count the number of white blood cells and other signs of infection.

An X-ray or ultrasound scan will show whether there is a collection of fluid building up around the lungs and how much there is. Often a CT scan may also be used to give a more detailed picture.

Treatment

There are a number of treatments for the condition. The health professional looking after your care will discuss the treatment options with you.

Treatment can include:

• antibiotics - some patients will just need antibiotics given intravenously (directly into a vein through a drip)
• chest drain - some patients may need both antibiotics and a chest drain (a flexible plastic tube inserted through the chest wall and into the affected area, to drain fluid)
• surgery - to remove the lung lining if the condition doesn't improve with the treatments above
• stoma - an opening made in the chest wall with a special bag placed over it to collect the fluid that leaks from the empyema

More useful links

• How to use your health services
• Empyema