The 2 most common causes of acute mediastinitis are
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 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 can be confirmed by chest x-ray or CT showing air in the mediastinum, although other disorders (eg, spontaneous pneumomediastinum) can also cause air in the mediastinum.
Treatment is with parenteral antibiotics selected to be effective against oral and gastrointestinal flora (eg, clindamycin 450 mg IV every 6 hours plus ceftriaxone 2 g IV once a day, for at least 2 weeks). Patients who have severe mediastinitis with pleural effusion or pneumothorax require emergency surgical exploration of the mediastinum with primary repair of the esophageal tear and drainage of the pleural space and mediastinum.
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.
This condition usually is due to tuberculosis (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.