Mediastinitis

Acute Acute mediastinitis is an infectious process and can cause fever, chills, and tachycardia. Pain can occur with mediastinitis but the location of the pain depends on which part of the mediastinum is involved. When the upper mediastinum is involved, the pain is typically retro-sternal pain. When the lower mediastinum is involved, pain can be located between in the scapulae and radiate around to the chest. Chronic Symptoms depend on what organs of the mediastinum the disease is affecting. They might be caused by a constricted airway, constricted esophagus, or constricted blood vessels. Symptoms also depend on how much fibrosis has occurred. There may be cough, shortness of breath, coughing up blood, pain in the chest, and difficulty in swallowing. == Causes ==

Acute Esophageal perforation, a form of direct contamination, accounts for 90% of acute mediastinal infections. Although Descending Necrotizing Mediastinitis is an acute mediastinitis, it is distinct because it does not originate from structures within the mediastinum. Therefore, the term Descending Necrotizing Mediastinitis implies that the infection of the mediastinum originated from a primary site in the head or neck and descended through fascial spaces into the mediastinum. Though rare in developed countries, acute mediastinitis can be caused by inhalation of bacterial spores such as Anthrax. Historically, this infection was referred to as ''Wool-sorter's Disease''. In the lungs, spores can spread via lymphatics to mediastinal lymph nodes, where the mature rods can release exotoxins promoting edema and tissue necrosis. Clinically, persons infected with anthrax can develop a hemorrhagic mediastinitis, which manifests as acute pulmonary hemorrhage and meningitis. Autoimmune disease and Behcet's disease are also causes. Often the culprits are usually Gram-positive bacteria and anaerobes, though rarely, Gram-negative bacteria are also present. This severe form represents 20% of acute mediastinitis cases. == Diagnosis ==

Acute Acute mediastinitis can be confirmed by contrast x-rays since most cases of acute mediastinitis are due to esophageal perforation. Other studies that can be used include endoscopic visualization, Chest CT scan with oral and intravenous contrast. With regards to CT Imaging, the extent of involvement of the mediastinum can be evaluated. Therefore, acute mediastinitis can be classified into three categories: • diffuse mediastinitis • isolated mediastinal abscess • mediastinitis or mediastinal abscess complicated by empyema or subphrenic abscess. Chronic Most cases of granulomatous mediastinitis (75%) are incidentally found on chest x-rays which show a mediastinal mass, or widening of the mediastinum. == Treatment ==

Treatment for acute mediastinitis usually involves aggressive intravenous antibiotic therapy and hydration. If discrete fluid collections or grossly infected tissue have formed (such as abscesses), they may have to be surgically drained or debrided. Treatment for DNM usually requires an operation to remove and drain infected necrotic tissue. Broad spectrum intravenous antibiotics are also given to treat the infection. Patients are typically managed in the intensive care unit due to the severity of the disease. Treatment for chronic fibrosing mediastinitis is somewhat controversial, and may include steroids or surgical decompression of affected vessels. == Prognosis ==

Fibrosing mediastinitis can lead to entrapment of mediastinal structures. The mortality of DNM ranges from 10 to 40% due to sepsis and multi-organ failure if not recognized and intervened upon early. ==References==