A pleural empyema
(also known as a pyothorax
or purulent pleuritis
) is an accumulation of pus
in the pleural cavity
. Most pleural empyemas arise from an infection within the lung
), often associated with parapneumonic effusions
. There are three stages: exudative
, fibrinopurulent and organizing. In the exudative stage, the pus accumulates. This is followed by the fibrinopurulent stage in which there is loculation of the pleural fluid (the creation of grapelike pus pockets). In the final organizing stage, scarring of the pleural space may lead to lung entrapment.
Symptoms of empyema may vary in severity. Typical symptoms include: fever, chest pain or discomfort, cough, sweating and shortness of breath.
Clubbing of the fingernails may be present. There is a dull percussion note and reduced breath sounds on the affected side of the chest. Other diagnostic tools include chest x-ray, CT scan, and ultrasonography.
Diagnosis is confirmed by thoracentesis
; frank pus may be aspirated from the pleural space. The pleural fluid typically has a low pH (<7.20), low glucose (<60 mg/dL), and contains infectious organisms.
Definitive treatment for empyema entails drainage of the infected pleural fluid. A chest tube
may be inserted, often using ultrasound guidance. Intravenous antibiotics
are given. If this is insufficient, surgical debridement
of the pleural space may be required.