The Analysis Of The Influence Factors Of The Ventilator-associated Pneumonia In Elderly Patients And The Method Of Disinfecting Endotracheal Tubes

ObjectiveThe object of this study is to analysis the influence factors and the distribution ofbacteria of ventilator-associated pneumonia (VAP), and to set up the VAP forecast model.Besides, to analyse and confirm the optimum cleaning disinfectants and cleaning times on PVC tracheostomy tube, in order to reduce the bacterial colonization and provide evidence for prevention and nursing of VAP.Methods1. Retrospective analysis: the data was collected on patients who aged over 80 and had received mechanical ventilation over 48 hours in our hospital from Jan 2011 to Dec 2015. According to the data collected, to analyse the risk factors of VAP and set up forecast model.2.Clinical trial study:?Self controlled before and after study: to included in 25 cases elderly patients using PVC endotracheal tubes from Jan 2016 to July. Using 6 different cleaning disinfectants (sterile saline, alcohol, compound iodine solution,0.5%hydrogen peroxide, 0.2% chlorhexidine, 2% intensified glutaraldehyde) clean and disinfect PVC endotracheal tubes, and the bacterial colony counts were analysed and compared. ?Randomized controlled trial: the topic of study is analysis of optimum cleaning times using 0.2%chlorhexidine. To included in 27 cases elderly patients using PVC endotracheal tubes from July 2016 to Nov, and randomly divided into three groups by every 24h, every 12h and every 8h.Results1. Analysis the influence factors and the distribution of bacteria of VAP1.1 Totally 901 patients were included in this study, of which 156 were diagnosed as VAP.The incidence of VAP was 17.3%.1.2 Logistic regression analysis showed the independent influence factors for elderly patients with VAP were the way of mechanical ventilation (OR=1.650,P<0.05),duration of mechanical ventilation (OR=2.346,P<0.01), number of antibacterials(OR=5.500,P < 0.01), department(OR=2.209,P < 0.001),duration of central venous intubation (OR=0.405 , P<0.01), number of central venous intubation (OR=2.041,P<0.05), duration of indwelling urinary catheter(OR=1.961,P < 0.05), the use of hormone (OR=1.611,P<0.05).1.3 A total of 353 pathogenic bacteria were identified. Among all VAP cases,gram-negative bacteria accounted for 68.8%, in which acinetobacter baumannii,pseudomonas aeruginosa, stenotrophomonas maltophilia was the major pathogen.Fungi occuping 21.4% and 9.7% were gram-positive cocci.1.4 The VAP forecast model based on influence factors P=1/(1+exp(7.714-0.792X1-0.853X2-0.501X3+0.903X4-0.714X5-0.673X6-1.705X7-0.477X8))2. Analysis different ways of cleaning and disinfecting on PVC endotracheal tubes within the wall of bacterial colonization2.1 The colonized gram-negative bacteria within the wall of PVC endotracheal tubes included pseudomonas aeruginosa, acinetobacter baumannii, proteus,stenotrophomonas maltophilia.2.2 Disinfection effect of 0.2% chlorhexidine, better than sterile saline, compound iodine solution, 0.5% hydrogen peroxide (P<0.05). According to 75% alcohol and 2%intensified glutaraldehyde, the disinfection way of 0.2% chlorhexidine is simple and has less adverse effect.2.3 There was significant difference among three groups. The effects of disinfecting colonized bacteria within the wall of PVC endotracheal tubes in groups 8h and 12h were different from 24h group(P<0.05).There was no significant difference between 8h group and 12h group.Conclusion1. The incidence of VAP was 17.3%. VAP was related with a variety of factors, such as the way of mechanical ventilation, duration of mechanical ventilation, number of antibacterials. Early detecting of high-risk patients by setting up forecast model of VAP to take corresponding nursing precautions.2. In our hospital, the main VAP pathogenic bacterium for elderly patients was gram negative bacilli. And the top three pseudomon were acinetobacter baumannii,pseudomonas aeruginosa, stenotrophomonas maltophilia. There are also pathogenic bacterium of gram positive and fungus. To provide guidance for the selection of disinfectants related to the mechanical ventilation of clinical care.3. Using 0.2% chlorhexidine every12h cleaning wall of PVC endotracheal tubes can make bacteria colonization rate was significantly lower.