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Mediastinitis
is inflammation of the mediastinum. Acute mediastinitis usually
results from esophageal perforation or median sternotomy. Symptoms
include severe chest pain, dyspnea, and fever. The diagnosis is
confirmed by chest x-ray or CT. Treatment is with antibiotics (eg, clindamycin
plus ceftriaxone) and sometimes surgery.
The two most common causes of acute mediastinitis are esophageal perforation and median sternotomy.
Esophageal perforation may complicate esophagoscopy or insertion of a Sengstaken-Blakemore or Minnesota tube (for esophageal variceal bleeding). It may rarely occur with forceful vomiting (Boerhaave's syndrome). Another possible cause is swallowing caustic substances (eg, lye or certain button batteries). Certain pills or esophageal ulcers (eg, in AIDS patients with esophagitis) can contribute.
Patients with esophageal perforation become acutely ill within hours, with severe chest pain and dyspnea due to mediastinal inflammation. Diagnosis usually is obvious from clinical presentation and the history of instrumentation or of another risk factor. The diagnosis should also be considered in patients who are very ill, have chest pain, and may have a risk factor that they cannot describe (eg, in intoxicated patients who may have vomited forcefully but do not remember and in preverbal children who may have ingested a button battery). The diagnosis is confirmed by chest x-ray or CT showing air in the mediastinum.
Treatment is with parenteral antibiotics selected to be effective against oral and GI flora, eg, clindamycin 450 mg IV q 6 h plus ceftriaxone 2 g once/day, for at least 2 wk. Patients who have severe mediastinitis with pleural effusion or pneumothorax require emergency exploration of the mediastinum with primary repair of the esophageal tear and drainage of the pleural space and mediastinum.
Median sternotomy:
This procedure is complicated by mediastinitis in about 1% of cases. Patients most commonly present with wound drainage or sepsis. Diagnosis is based on finding infected fluid from a needle aspiration through the sternum. Treatment consists of immediate surgical drainage, debridement, and parenteral broad-spectrum antibiotics. Mortality approaches 50% in some series.
Chronic fibrosing
mediastinitis:
This condition is usually is due to TB or histoplasmosis but can be due to sarcoidosis, silicosis, or other fungal diseases. Patients develop an intense fibrotic process that leads to compression of mediastinal structures that can lead to the superior vena cava syndrome, tracheal narrowing, or obstruction of the pulmonary arteries or veins.
Diagnosis is based on CT scan. If the cause is TB, anti-TB therapy is indicated. Otherwise, no known treatment is beneficial, but insertion of vascular or airway stents can be considered.
Last full review/revision February 2008 by Richard W. Light, MD
Content last modified February 2008
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