【作者】 李青；

【导师】 阳爱云；

【作者基本信息】 中南大学 ， 护理， 2007， 硕士

【摘要】 目的：本研究针对ICU中接受机械通气的患者，从基因水平对该类患者呼吸机管道内定植细菌与下呼吸道致病菌进行同源性分析，希望通过深入、可信的研究结果，为临床预防VAP的发生提供可靠依据。对象与方法：1．采用临床实验的方法，在综合ICU中对30名机械通气患者收集24小时内、第三天、第五天、第七天口咽部分泌物、下呼吸道吸出物和呼吸机管道内的冷凝水进行细菌培养，分析各部位定植菌种类、数量、定植时间，结合临床表现及辅助检查结果将患者群体分为感染组(发生VAP)和非感染组(未发生VAP)。2．在病例组中，根据同一患者口咽部、下呼吸道、呼吸机管道分离的同种定植菌生物学反应是否相同，又分为感染1组(生化反应相同)和感染2组(生化反应不同)，用RAPD-PCR的方法从基因水平对病例1组进行同源性鉴定，再结合这些细菌定植时间上的先后次序推断感染的途径。3．用单因素分析法对VAP发生的可能危险因素进行分析。结果：1在30个病例中，有14例发生VAP，感染率为46.67％，致病菌以革兰氏阴性杆菌为主，其中醋酸钙不动杆菌为优势菌种。2 RAPD-PCR实验显示：在病例组中有35.71％患者呼吸机管道内的定植菌与VAP致病菌有同源性表现；有21.42％的患者在具备同源性的基础上，呼吸机管道内细菌定植时间先于下呼吸道，且定植时间多在上机第3天左右。3上机第3天左右是管道细菌定植的高峰时间。污染途径有口咽、下呼吸道定植菌移行和外源性污染三种。4上机第5天左右是VAP发生的高峰时间。5留置胃管时间、呼吸机管道细菌定植量、呼吸机管道首次细菌定植时间是VAP发生的危险因素。6在同一病区的相同时间段，不同患者间出现具有同源性特点的定植菌。结论：1呼吸机管道更换的最佳时间是3-4天2呼吸机管道内定植菌的移行是导致VAP发生的重要原因之一。3留置胃管时间、呼吸机管道细菌定植量、呼吸机管道首次细菌定植时间是VAP发生的危险因素，而性别、年龄、原发疾病、大手术、神志则与VAP发生没有明显相关性。4机械通气患者中VAP的发生率为46.67％。更多还原

【Abstract】 OBJECTIVES: This study to aim directly at patients that receivingmechanical ventilation in ICU, the purpose of colonization bacteria inventilator circuit on molecular level to provide the one trial base fortreatment and prevention in clinical.METHODS:I A clinical trial in 30 patient of receiving ventilatorsupport to collect their oropharynx excretion, tracheal aspirate andcondensed water in ventilator circuit to bacterial culture with on thewithin 24 hours, third days, fifth days and seventh days. Patients weredivided infection group and non-infection group. The types and amountthat field planting bacterium and attack rate were analyzed. 2 In infectiongroup, if the colonization bacteria in ventilator circuit, pathogens of VAPand colonization bacteria of oropharynx showed same biochemicalcharacteristics and colonization order in same patients who were dividedinfection 1 group and infection 2 group; the isolates were analyzed withRAPD-PCR to study their homology. 3 make single factor analysis toanalyze all the risk factor.RESULTS: 1 In the cases, fourteen cases of the total 30 intubatedpatients supported by mechanical ventilation developed VAP. Infectionrate was 47%. The Gram-negative bacteria were major in pathogens forVAP. 2 RAPD-PCR showed most homology of pathogens for VAP andbacteria in ventilator circuit with 35.71% patients in all cases. The time was before bacteria colonization in Ventilator circuit than lowerrespiratory tract with 21.42% patients. Colonization time on planes 3daysto 4days after used mechanical ventilation. 3 Apex time was 3days afterused mechanical ventilation in bacteria colonization from Ventilatorcircuit. 4 Apex time was 5days after used mechanical ventilation in toappear VAP. 5 the time of to detain a gastric tube, the amount of bacteriafrom ventilator circuit and the time of bacteria in ventilator circuit at firstare potential risk factors. 6 At same endemic area and meantime segmentto appear cross infection.CONCLUSION: 1 3day to 4day was the best time to be changeventilator circuit. 2 A possible bacterial origin which translocated fromventilator circuit to low respiratory tract and may contributes to theoccurrence of VAP. 3 The time of to detain a gastric tube, the amount ofbacteria that ventilator circuit and the time of bacteria that ventilatorcircuit at first are potential risk factors. 4 The VAP attack rate in patientssupported by mechanical ventilation was 46.67%.更多还原