医院获得性肺炎 ,是指入院时不存在、也不在潜伏期而于入院 4 8小时以后发生的肺炎。病人在住院期间由细菌、真菌、支原体、病毒或原虫等引起的肺实质炎症。临床上有时将医院肺炎与医院内下呼吸道感染的概念相混用。国内将病变局限于气道者定义为院内获得性气管———支气管炎 Hospital-acquired pneumonia is pneumonia that does not occur on admission and is not in the incubation period and occurs 48 hours after admission. The patient’s parenchymal inflammation of the lungs caused by bacteria, fungi, mycoplasmas, viruses or protozoa during hospitalization. Clinically, hospital pneumonia is sometimes mixed with the concept of lower respiratory tract infection in hospitals. Domestic lesions limited to the airways are defined as hospital acquired trachea - bronchitis