机械通气作为一种重要的呼吸支持手段,已常规应用于对呼吸衰竭患者的抢救与维持[1]。随着机械通气时间的增加,不但延长了患者的住院时间,同时也增加了病原菌定植的机会,从而引发了呼吸机相关性肺炎(VAP)。而VAP是导致患者住院时间延长、经济负担加重和院内感染 As an important means of respiratory support, mechanical ventilation has been routinely applied to the rescue and maintenance of respiratory failure patients [1]. With the increase of mechanical ventilation time, it not only prolongs the hospitalization time of patients, but also increases the opportunity of colonization of pathogens, which leads to ventilator-associated pneumonia (VAP). The VAP is leading to prolonged hospitalization, increased financial burden and nosocomial infections