Study On Pathogens And High Risk Factors Of Ventilator-Associated Pneumonia In ICU

OBJECTIV To study the distribution and antimicrobial resistance of bacteria and the risk factors of ventilator-associated pneumonia(VAP) in order to provide evidence for prevention and therapy of VAP.METHODS(1)With Prospective method,the morbidity and the mortality of VAP and the related risk factors,such as the years,sex,the score of APACHEII,consciousness condition,the lasting time of mechanical ventilator,microorgnism cononization in oropharynx or in the tube of ventilator and the way of mechanical ventilation and other factors were ivestigated on VAP patients which in one of three grade hospital during January -December2007.(2)Etiologyic diagnosis was established under quantitative culture of endotracheal aspiration.All the pathogens were analysised by VITEK,which made in Biomerieux company.(3)Drug-resistance test with K-B methods according to the rules of NCCLS,(4)The cases were divided into the infection group and the control group.Univariate chi-square was conducted and then Non-condition Logistic regression analysis of the markedly different factors in the two groups was employed in SPSS15.0.RESULTS(1) Totally 236 patients were enrolled in this study,of which 98 were diagnosed as VAP.The morbidity of VAP was 41.52%.The mortality was 37.76%;(2)A total of 133 pathogens were identified.Among all the strains casing VAP,Gram-negative bacteria accounted for 72.04%,in which pseudomonas aeruginosa was the major pathogen.Gram positive cocci occuping 20.43%and 7.53%were fungi;(3)VAP was related with such factors as the age over 60 years(x~2=20.258),the score of APACHEII(x~2=44.051), consciousness condition(x~2=9.399),the lasting time of mechanical ventilator(x~2=21.732),microorgnism cononization in oropharynx(x ~2=13.355) or in the tube of ventilator(P＜0.05) and the way of mechanical ventilation(x~2=7.448);(4)The major risk factors might be the score of APACHEII than or equal to 15(OR=1.175),the age over 60 years (OR=1.069),the lasting time of mechanical ventilator than or equal to 7days(OR=1.008),the way of mechanical ventilation(OR=0.203) and microorgnism cononization in the humidifier of ventilator(OR=0.024)CONCLUSION(1)Gram-negative bacteria were the most common pathogens of VAP,which presented to multi-drug resistant pattern.Gram positive cocci to vancomycin were all 100%.Clinician should choose antimicrobial agents according to antimicrobial susceptibility test result in time.(2) There were multiple factors result in VAP.It is suggested that precaution against VAP such as enhance our survey on the risk factors of VAP, attach important to bacteria-free operation technology,reduce pollution in the tube of ventilator by bacteria,shorten the durating of invasive mechanical ventilation so as to contral incidence rate of VAP.