密闭式呼吸机湿化管道系统细菌培养分析

Analysis of bacterial colonization in the ventilator circuits and humidification systems

目的了解机械通气患者呼吸机湿化管道系统细菌定植情况,为湿化管道系统的更换时间及临床护理操作提供参考。方法选择采用密闭式呼吸机湿化管道系统机械通气超过72h以上的患者276例,分别于上机72h、168h、240h、336h、504h、672h采集呼吸机湿化管道系统标本进行细菌培养检测。结果共采集标本数3 271个,分离出病原菌9种541株。其中,呼吸机管道403株,冷凝水124株,湿化罐湿化液14株,均以革兰阴性杆菌为主。不同机械通气时间下,呼吸机管道、冷凝水、湿化罐湿化液细菌培养阳性率比较,差异无统计学意义(均P>0.05)。结论采用密闭式呼吸机湿化管道系统,呼吸机管路、湿化罐湿化液的细菌定植量不随着机械通气时间的延长而增加,且湿化液在没有污染的情况下可延长至28d更换1次。

Objective To explore bacterial colonization in the ventilator circuits and humidification systems, and to provide reference for change intervals in clinical practice. Methods Totally, 276 patients on mechanical ventilation using closed circuits and humidifica tion systems for over 72 h,were enrolled . Samples from the ventilator circuits and humidification systems were harvested at 72 h, 168 h, 240 h, 336 h, 504 h, and 672 h and cultivated for bacteria. Results In total, 3 271 samples were collected and 541 strains of pathogens were found, belonging to 9 different categories. Most of them were gram negative bacilli, with 403 strains found in ventilator circuits, 124 in condensate formed in mechanical ventilators, and 14 in liquid in the humidifiers. No significant differences were observed in the pathogens in ventilator circuits, condensate formed in mechanical ventilators, or in the humidifiers, for diffe- rent lengths of ventilation （P〉 0.05 for all）. Conclusion The number of bacterial colonization in ventilator circuits, condensate formed in mechanical ventilators, or in the humidifiers doesnt t increase with duration of mechanical ventilation. Moreover, if not contaminated, the liquid in the humidifiers can be changed at an interval of 28 d.