Skip to Main Content

Empyema is pus in the pleural space, and the definition includes pleural space infections with a positive Gram stain or culture, or parapneumonic effusions without pleural fluid sampling. Additional causes of empyema besides pneumonia are: complications of chest or abdominal trauma, esophageal perforation, extension from a lung abscess, osteomyelitis or other near pleural infections, or a hemothorax, chylothorax, or hydrothorax that becomes infected.

Predisposing factors for empyema include aspiration pneumonia and its associated risk factors, such as neurologic disease impairing normal swallowing, respiratory disease impairing ciliary function, immunocompromise, and alcoholism. An underlying bacterial pneumonia is the most common cause of empyema. The common organisms in empyema stratified by associated pathology are listed in Table 69-1.

Table 69-1 Common Organisms in Empyema and Associated Pathology

Clinical Features

Empyema is usually preceded by pneumonia. Empyema should be suspected if symptoms of pneumonia (fever, cough, dyspnea, pleuritic chest pain, and malaise) do not resolve. The onset of empyema may also be insidious. Patients may appear chronically ill with weight loss, anemia, and night sweats, and frequently have underlying risk factors: neurologic disease, pulmonary disease, malignancy, alcoholism, human immunodeficiency virus, and other immunocompromised states.

Physical examination findings include: decreased breath sounds, dullness to percussion, decreased tactile fremitus, and, occasionally, a friction rub. Pain from an underlying effusion or empyema may cause splinting with respiration. If there is an underlying pulmonary infection, rales or rhonchi may be heard.


Diagnostic criteria for empyema are: aspiration of grossly purulent material on thoracentesis and at least one of the following: thoracentesis fluid with a positive Gram stain or culture, pleural fluid glucose <40 milligrams/dL, pH <7.1, or lactate dehydrogenase >1000 IU/L.1 Empyema has three stages that impact treatment:

  1. 1. Exudative (may be very short, <48 hours, the free-flowing pleural effusion that is present is amenable to chest tube drainage)

    2. Fibrinopurulent (fibrin strands form in the pleural fluid causing loculations, resolution of the empyema with single chest tube drainage is unlikely)

    3. Organizational (takes several weeks, more extensive fibrosis, “pleural peel” restricts lung expansion)


The treatment of underlying conditions, such as pneumonia or heart failure, should begin in the ED. Pleuritic pain should be treated with appropriate NSAIDs or opioids. Thoracentesis may be needed in the ED to stabilize a patient with respiratory or cardiac ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.