Comparison Study On The Impact Of Ventilator-associated Pneumonia For COPD Patients With Different Ventilator Circuit Replacement Time

Objective: The aim of this study was to explore the impact of ventilator-associated pneumonia for COPD patients with different ventilator circuit replacement time. Methods: This design was a randomized clinical trial with 120 cases of COPD patients,who needed for invasive mechanical ventilation in RICU of People's Hospital of the autonomous region. According to the order of admission, the selected patients were randomly divided into control group and experimental group, each of which contained 60 cases. The control group's ventilator circuits were replaced everyday, while the experimental group ever 4 days. Collected secretion samples from each ex-30 patients of the two groups at the time of using the ventilator 24 h, 48 h, 72 h, 96 h. The samples were collected form ventilator inlet, outlet circuit inner surface before ventilator circuit being replaced, and then the samples were taken bacteriological examination. The bacteria which had been trained in two consecutive times were the right pathogen bacteria. Results:①Before invasive mechanical ventilation, the COPD patients all have variances lung infections, which were called almost by gram positive coccus and gram negative bacilli. The first three pathogen bacteria were Streptococcus viridans(23.3%), Neisseria(19.2%) and Candida albicans (10%).②The first occurrence rate of VAP in COPD patients was 34.2%, while occurred at the (5.66±2.95) days. The bacteriological examination illustrated that the primary bacteria were gram negative bacilli (62%), and the first three ones were as follows: Acinetobacter baumannii(26%),Pseudomonas aeruginosa(18%)and Staphylococcus epidermidis(12%). The recurrence rate of VAP was 17.5%, the recurrence time was (9.86±4.03) days, and the dominated bacteria was Klebsiella pneumoniae bacteria (22.6%).③In experimental group, the vitiate rate of ventilator circuit has no significant difference between 24 hours, 48 hours, 72 hours, but this rate in 96 hours was obviously high than 24 hours, 48 hours, 72 hours. The rate in outlet circuit was higher than that of inlet circuit(P<0.05).④The rates of VAP's occurrence and reoccurrence in the experimental group were all lower than those in the control group(P<0.05).Conclusion:①The first occurrence rate of VAP in COPD patients was 34.2%, and the reoccurrence rate was 17.5%, and gram negative bacilli were the primary bacteria, and the first three bacteria were Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus epidermidis.②COPD patients'VAP occurrence peak time was 5days after used mechanical ventilation.③The number of ventilator circuit bacteria colonization increased significantly at 4th day, so it is suggested that the appropriate time was to replace the ventilator circuit of COPD patients in every 4 days.