呼吸机相关肺炎(ventilator associated pneumonia,VAP)是指经气管插管或气管切开并行机械通气≥48h,停止机械通气及拔除气管导管后48h内新发生的肺实质感染性炎症。VAP是医院内获得性肺炎最常见的类型之一。由于VAP患者住院时间长,医疗成本高,死亡率高,了解其发病机制和对应的 Ventilator-associated pneumonia (VAP) refers to the new infectious pulmonary inflammatory disease occurring within 48 hours after tracheal intubation or tracheotomy in parallel with mechanical ventilation ≥48 hours, after stopping mechanical ventilation and removing the tracheal tube. VAP is one of the most common types of hospital acquired pneumonia. Due to the long hospital stay of VAP patients, the high cost of medical treatment and the high mortality rate, its pathogenesis and its corresponding