The 2 most common causes of acute mediastinitis are
Esophageal perforation Esophageal Rupture Esophageal rupture may be iatrogenic during endoscopic procedures or other instrumentation or may be spontaneous (Boerhaave syndrome). Patients are seriously ill, with symptoms of mediastinitis... read more 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 Pneumomediastinum Pneumomediastinum is air in mediastinal interstices. The main causes of pneumomediastinum are Alveolar rupture with dissection of air into the interstitium of the lung with translocation to... read more ) 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 Pleural Effusion Pleural effusions are accumulations of fluid within the pleural space. They have multiple causes and usually are classified as transudates or exudates. Detection is by physical examination and... read more or pneumothorax Pneumothorax Pneumothorax is air in the pleural space causing partial or complete lung collapse. Pneumothorax can occur spontaneously or result from trauma or medical procedures. Diagnosis is based on clinical... read more 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.
Chronic fibrosing mediastinitis
This condition usually is due to tuberculosis (TB) Tuberculosis (TB) Tuberculosis is a chronic, progressive mycobacterial infection, often with an asymptomatic latent period following initial infection. Tuberculosis most commonly affects the lungs. Symptoms include... read more or histoplasmosis Histoplasmosis Histoplasmosis is a pulmonary and hematogenous disease caused by Histoplasma capsulatum; it is often chronic and usually follows an asymptomatic primary infection. Symptoms are those... read more but can be due to sarcoidosis Sarcoidosis Sarcoidosis is an inflammatory disorder resulting in noncaseating granulomas in one or more organs and tissues; etiology is unknown. The lungs and lymphatic system are most often affected, but... read more , silicosis Silicosis Silicosis is caused by inhalation of unbound (free) crystalline silica dust and is characterized by nodular pulmonary fibrosis. Chronic silicosis initially causes no symptoms or only mild dyspnea... read more , or other fungal diseases. An intense fibrotic process develops, leading to compression of mediastinal structures that can cause the superior vena cava syndrome Regional spread , 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.