机械通气患者气管导管内生物被膜生成及病原分析

The characteristics of biofilm formation in endotracheal tubes in ventilated patients

目的观察呼吸重症监护病房（RICU）内气管插管患者生物被膜病原学特点和耐药情况。方法选取2006年9月至2007年3月入住河北医科大学第二医院RICU内有创机械通气患者39例，其中男27例，女12例，平均（65±14）岁。通过前瞻性队列研究，电镜观察气管插管患者生物被膜形成时间分布特征，分析病原菌时间相关性特点和耐药情况。采用SPSS11．5软件，计数资料进行趋势χ^2检验。结果39例气管插管患者中21例（53．85％）出现呼吸机相关肺炎（VAP）。机械通气后2—7d，导管内壁有点片状生物被膜形成；机械通气7～10d，有87．5％（34／39）的导管内形成了片状生物被膜，10d以后所有的导管内均形成了生物被膜。结论随着有创机械通气时间的延长，VAP患病率逐渐增高，耐药细菌感染增多，并且与被膜内病原菌种趋向一致。

Objective To evaluate the etiology and drug resistance of biofilms in endotracheal tubes in respiratory intensive care unit （RICU）. Methods A prospective cohort study was conducted. The biofilms were observed by scanning electron microscopy at different times of ventilation. The pathogens were identified and their resistance to antibiotics were analyzed. Results Twenty one VAP cases were identified in 39 mechanically ventilated patients （53.85%）. Patchy biofihns were observed 2 d to 7 d after the initiation of ventilation. After 7 d to 10 d, 87. 5% of the endotracheal tubes were covered by biofihns. Biofilms were identified in all the tubes longer than 10 d. Conclusions The incidence of VAP increased with prolonged mechanical ventilation. Meanwhile the antibiotic resistance rate increased and more pathogens isolated were consistent with those in the biofilms.