呼吸机相关性肺炎(ventilator-associated pneumonia,VAP)是一种医院获得性感染,指原无肺部感染的呼吸衰竭患者在气管插管或切开机械通气治疗后48 h,或原有肺部感染用呼吸机48 h以上发生新的病情变化(临床高度提示为一次新的感染并经病原学证实),或拔管后48 h内发生的肺实质的感染性炎症[1]。VAP分为:(1)早发 Ventilator-associated pneumonia (VAP) is a hospital-acquired infection that refers to patients with respiratory failure who have not previously had a lung infection at 48 h after intubation or mechanical ventilation, Infection with ventilator 48 h or more new changes in the condition (clinical highly suggestive of a new infection and confirmed by etiology), or within 48 h after extubation pulmonary parenchymal infectious inflammation [1]. VAP is divided into: (1) early onset