[Acute Mediastinitis].

Acute mediastinitis is a deep thoracic infection. In particular, descending necrotizing mediastinitis (DNM) is serious and potentially fatal, however, the initial symptoms are often not severe. It is caused by prolonged oropharyngeal or odontogenic infections such as pharyngitis, tonsillitis, and dental caries. The most common pathogens are Gram-positive cocci and anaerobes, and patients often have underlying medical conditions such as diabetes mellitus, steroid use, and chronic renal failure. Surgical drainage is necessary for treatment, and surgery should be performed as soon as possible after diagnosis. The mortality rate of DNM was initially reported to be more than 40%, but has improved to less than 20% in recent years. Proper judgment and appropriate surgery have contributed to the improvement of the life-saving rate.