1．急性縦隔炎

Acute Mediastinitis

急性縦隔炎，特に降下性壊死性縦隔炎（descending necrotizing mediastinitis：DNM）は致死率の高い激烈な感染症である1～4）．しかし遭遇機会が少なく，初見例では判断が後手になりやすい1，4）．本稿では若手医師が本疾患に初遭遇した場面を想定し，実戦的な情報にも言及したい．

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.