Mediastinitis is inflammation of the mediastinum. Acute mediastinitis usually results from esophageal perforation or occurs after median sternotomy. Symptoms include severe chest pain, dyspnea, and fever. The diagnosis is suggested by chest x-ray and usually confirmed by CT. Treatment is with antibiotics (eg, clindamycin plus ceftriaxone) and sometimes surgery.Mediastinitis is inflammation of the mediastinum. Acute mediastinitis usually results from esophageal perforation or occurs after median sternotomy. Symptoms include severe chest pain, dyspnea, and fever. The diagnosis is suggested by chest x-ray and usually confirmed by CT. Treatment is with antibiotics (eg, clindamycin plus ceftriaxone) and sometimes surgery.
The 2 most common causes of acute mediastinitis are
Esophageal perforation
Median sternotomy
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 syndrome). Another possible cause is swallowing caustic substances (eg, lye, certain button batteries). Certain pills or esophageal ulcers (eg, in patients with AIDS and 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 patients who are intoxicated and may have vomited forcefully but do not remember and in preverbal children who may have ingested a button battery). The diagnosis is suggested by chest x-ray showing air in the mediastinum and confirmed by CT, 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 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 withpleural 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.
Median sternotomy
This procedure is complicated by mediastinitis in about 1% of cases (1). 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. Mediastinitis after median sternotomy has a high mortality rate.
Chronic fibrosing mediastinitis
This condition usually is due to tuberculosis (TB) or histoplasmosis but can be due to sarcoidosis or silicosis. Other fungal diseases may also cause chronic fibrosing mediastinitis.
An intense fibrotic process develops, leading to compression of mediastinal structures, which 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 or fungal, antimicrobial therapy is indicated. Otherwise, no known treatment is beneficial, but insertion of vascular or airway stents can be considered.
Reference
1. De Feo M, Renzulli A, Ismeno G, et al. Variables predicting adverse outcome in patients with deep sternal wound infection. Ann Thorac Surg 2001;71(1):324-331. doi:10.1016/s0003-4975(00)02137-8
