医院获得性肺炎(NP)是指病人住院48～72小时后发生的,或住院期间无临床症状而出院后才表现出来的下呼吸道感染。据报道,美国NP的发病率占全部医院获得性感染的第三位,国内NP的发病率为10～20%,病死率为25～50%。引起NP的病原体有细菌、病毒、霉菌、支原体、衣原体及寄生虫,其中以细菌性肺炎占大多数。据 Hospital Acquired Pneumonia (NP) refers to a lower respiratory infection that occurs after a patient has been hospitalized for 48-72 hours, or has been hospitalized without clinical symptoms and discharged from the hospital. According to reports, the incidence of NP in the United States accounted for the third among all hospital-acquired infections. The incidence of domestic NP was 10 to 20% and the case fatality rate was 25 to 50%. Pathogens causing NP are bacteria, viruses, molds, mycoplasma, chlamydia and parasites, of which the majority of bacterial pneumonia. according to