The Homology Study On Colonization Bacteria From Ventilator Circuit And Pathogens Of Ventilator-associated Pneumonia

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%.