为了解我院ＩＣＵ近年来呼吸道定植菌的变迁和指导机械通气相关肺炎 (ＶＡＰ)的抗生素治疗 ,对自 1995年起对ＩＣＵ中机械通气 (ＭＶ)病例的下呼吸道分泌物进行了细菌学的系列监测 ,现总结如下。资料与方法一、病例选择　 1995年 1月～ 2 0 0 1年 12月我院ＩＣＵ住院的ＭＶ≥ 4 In order to understand the changes of respiratory tract colonization bacteria in our hospital in recent years and to guide the antibiotic treatment of mechanical ventilation-associated pneumonia (VAP), a series of bacteriological studies on lower respiratory secretions of mechanical ventilation (MV) cases in ICU since 1995 Monitoring, are summarized as follows. Materials and Methods First, the selection of patients January 1995 ~ December 2001 hospital ICU hospital MV ≥ 4