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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 2 most common causes of acute mediastinitis are
Esophageal perforation:
Esophageal perforation may complicate esophagoscopy or insertion of a Sengstaken-Blakemore or Minnesota tube (for esophageal variceal bleeding). Rarely, it results from forceful vomiting (Boerhaave's syndrome). Another possible cause is swallowing caustic substances (eg, lye, 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 is usually obvious from clinical presentation and a 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 obtained by 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 usually is due to TB or histoplasmosis but can be due to sarcoidosis, silicosis, or other fungal diseases. An intense fibrotic process develops, leading to compression of mediastinal structures that can cause the superior vena cava syndrome, tracheal narrowing, or obstruction of the pulmonary arteries or veins.
Diagnosis is based on CT. 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 May 2012 by Richard W. Light, MD
Content last modified March 2012
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