医院获得性肺炎(Ｈｏｓｐｉｔａｌａｃｑｕｉｒｅｄｐｎｅｕｍｏｎｉａ,ＨＡＰ)是指患者入院时不存在,也不处于感染潜伏期,于入院48ｈ后发生的肺炎。以美国为例,其ＨＡＰ发病率为05%～10%,其中内、外科ＩＣＵ高达15%～20%,死亡率为50%～90%,仅此增加的医疗费多达每年20亿美元〔 Hospitals with Hospitals (HAP) refer to patients with pneumonia that are not present on admission nor in the incubation period of infection and occur 48 hours after admission. In the United States, for example, the incidence of HAP is between 05% and 10%, of which the intra- and surgical ICU is as high as 15% to 20% with a mortality rate of 50% to 90%. The increase in medical expenses alone amounts to as much as $ 2 billion annually