Study On High Risk Factors And Etiology Of Ventilator-associated Pneumonia In 99 Prematures

Backgroud: Ventilator-associated pneumonia(VAP) is the disease which infected in hospital after cannulaing and mechanical ventilation for the time which is longer than 48 hours. It is a serious complication which affected the prognosis of the prematures who have used the mechanical ventilation. It is also the reson why the prematures aboved will infected in hospiatal, die, live in hospital for longer time, and they must must pay much more money. The premature is the sepecial group in neanates. The quantity of the prematures which have sended to the hospital is much more than before for some reason such as the development of medical science and the adnantagement of society. The premature has been the main member of the neonatal intensive care unit(NICU). The sum of the premature who need the therapeutic measure of the mechanical ventilation is more and more. Immaturing for every organ in the premature, they have less ability to suit the environment, have less immunity, so they are up to be infected by the pathogenic bacteria. The VAP attacked rate is more than that of neonates. If the baby has attaked by the VAP, the VAP patients will be difficult to take out of service of the breathing machine, VAP may induce the attacked premature to be defeated in the therapeutic measure of the mechanical ventilation, or even to die. So the VAP has been payed close attention by more and more people. The mortality of VAP is high constantly. Curative effect of VAP directly determine the prognosis, survival rate and living quality. If we can prevent the onset of VAP, or once the VAP happened we can give effective therapeutic measure, the healing level of premature will be to leap.Objective: To explore the preventions and treatments of ventilator-associated pneumonia(VAP) in premature, we analyzed the etiology and high risk factors of VAP in premature in the neonatal intensive care unit(NICU).Methods: A retrospective study was conducted at the No.1 affiliated hospital of Jilin university. The objects contains 99 patients who had the hours of mechanical ventilation≥48h and admitted to the NICU from Mar. 2007 to Mar. 2008. Among the patients, mechanical ventilated prematures who suffered VAP were included in a observed group, and non-VAP prematures were in a control group. Case-control method, single-fastor analysis with Chi-square test and multiple logistic regression were performed to determine risk factors such as gender, gestation age, birth weight, ventilation hour, delivery way, asphyxia, birth defect, primary lung disease, preventative using antibiotic, airway suctioning, anaemia, septemia, surgery, thoracic close drainage, CNS suppressant, parenteral nutrition (PN), preventative using IVIG, reintubation, and so on. At the same time, we analyzed the results of tracheal aspirates cultures and drug sensitivity test in VAP premature to determine pathogenic microorganism and the severity of drug fast.Results: There were 64 episodes of VAP in 99 patients who were mechanically ventilated more than 48 hours. The incidence of VAP was 64.6%. By multiple logistic regression analysis, reintuba- tion (OR=8.166, 95%CI=1.191~55.977), duration of mechanical ventilation (OR=6.054, 95%CI=2.032~18.037), airway suctioning (OR=5.970, 95%CI=1.590~22.420), gestation age (OR=5.226, 95%CI = 1.896~14.408), primary lung disease(OR=4.582, 95%CI = 1.082~19.412), anaemia(OR=4.159,95%CI=1.178~14.685), treat- ment with CNS suppressant (OR=4.127, 95%CI=1.100~15.485) independently predicted neonatal VAP. The main pathogens were G-negative bacterium (75%). Klebsiella pneumoniae was the most isolated bacteria among gram-negative strains (25%), Pseudomonas aeruginosa is the second, Baumanii is the third. The Staphylococcus epidermidis was the most common isolated bacteria among gram- positive strain (12.5%), Staphylococcus aureus is the second. One Saccharomyces albicans was also isolated (3.125%). Gram-negative bacteria were sensitive to Amikacin and Meropenem. The sensitive rates of gram-positive cocci strains to Vancomycin were all 100%.Conclusion: Incidence and fatality of prematue which affected by VAP is high. Occurs at significant rates among mechanically ventilated prematures is associated with processes of care. The risk factors of premature VAP were reintubation, duration of ventilation, airway suctioning, gestation age, primary lung disease, anaemia, eatment with CNS suppressant. Additional studies are necessary to develop interventions to prevent prematural VAP. Gram-negative bacteria are the main pathogens causing VAP in prematures in NICU, and bacteria strains have high anti-microbial resistance,the Gram-positive bacteria is the second pathogens, there is also fungi has been founed. Clinicians should choose antimicrobial agents according to pathogen and antimicrobial susceptibility test result.