社区获得性肺炎 (communityacquiredpneumonia ,CAP)是指在医院外罹患的感染性肺实质炎症 ,即在医院外得的肺炎[1] 。资料显示 :CAP仍是威胁人类健康的重要疾病。近年来 ,由于人口的老龄化、免疫抑制疾病的增加、病原体变迁和抗生素耐药率的上升 ,使重症肺炎比例增加 ,也加重了 Community-acquired pneumonia (CAP) refers to infectious pulmonary parenchymal disease outside the hospital, which is pneumonia outside the hospital [1]. Data show: CAP is still an important disease that threatens human health. In recent years, due to the population aging, the increase of immunosuppressive diseases, the change of pathogens and the increase of the rate of antibiotic resistance, the proportion of severe pneumonia is increased, which also aggravates