The Study Of Nosocomial Infection In Neonatal Intensive Care Unit

Part 1 The Occurrence of Nosocomial Infection in Neonatal Intensive care unit and Pathogen DistributionObjective To study the occurrence of nosocomial infection(NI for short) situation in the neonatal intensive care unit(NICU)and analyse the pathogen distribution and variation tendency.Method A retrospective cohort was performed fron 2009 to 2013 in NICU of Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, of which all neonates hospitalized over 48 hours were included. Chi-square test and t-test were performed for statistical analysis.Results There were 3396 cases staying longer than 48 hours in the cohort study, with 421 cases occurred 456 times NIs. The overall incidence of NI was 13.43%, the incidence density was 9.57 per 1000 NICU patient-days. The NI rate was on the up trend from 2009 to 2013 and differences were statistically significant(X2=12.954,P=0.012). The most common infection type is pneumonia(41.45%) andsepticemia(22.37%).The major microorganism were Klebsiella pneumonia(24.36%) and Acinetobacter baumannii(17.00%). The drug sensitivity of Klebsiella pneumonia and pseudomonas aeruginosa to cefepime, imipenem, meropenem,amikacin, gentamicin and le vofloxacin reduced.Conclusion The rate of NI in our NICU was on the rise, so we should take measure actively to control NI. The drug sensitivity of main pathogen to common antibiotics is reduced, so we should strengthen the management of antibiotics and use antibiotics reasonably.Part 2 Risk factors of Nosocomial InfectionObjective To study the risk factors of nosocomial infection, and to provide reference for prenvention and control the nosocomial infectionMethod Analyzed the clinical data of the NI and non-NI children from January 1, 2009 to December 31, 2013 in our NICU by case-control study, including general information, the history of birth,pregnancy history and information of treatment, and the factors relevant to NI carry Logistic stepwise regression analysis further.Results Single factor analysis show gender(male), gestational age, low birth weight, low Apgar score, the history of asphyxia recovery, mother with intrapartum feer, gestational hypertension, pregnancy with hepatitis, intravenous nutrition, indwelling gastric tube, mechanical ventilation, PICC, the chest closed drainage, catheter, chest surgery history, transfusion history are related to hospital-acquired infection by case-control study between the 411 cases of NI neonates and the 2881 cases of non-NI neonates. Logistic stepwise regression analysis showed that the independent risk factors of NI were 1 minute Apgar score low, history of asphyxia recovery, mechanical ventilation, PICC, chest closed drainage and the history of chest or abdomen surgery before infection..Conclusion Low 1 minute Apgar score, history of asphyxia rescue and intrusive equipment and invasive operation such as mechanical ventilation, PICC, the chest closed drainage and surgery before infection increase the risk of nosocomial infection.Part 3 The Research of nosocomial invasive fungal infectionObjective Analyze the clinical features, pathogenic distribution and exposure of risk factors of nosocomial invasive fungal infections(IFI for short) in NICU, to provide reference for clinical diagnosis and treatment.Method Adopt the method of retrospective study to collected clinical data of neonates whose NICU stay is more than 48 hours from January 1, 2009 to December 31, 2013, and analyze invasive fungal infection rate and change trend of incidence, pathogenic distribution, exposure risk factors, diagnosis, treatment and prognosis in our hospital.Results 63 cases of neonates got nosocomial invasive fungal infections in this study, the total incidence of IFI was 1.86%(63/3396), the rate in all NI neonates was 14.96%(63/421). Incidence is high in summer and autumn. In the IFI cases, the rate of low birth weight and preterm infants are both 82.54%. The IFI neonates usually appearred repeated apnea, feeding intolerance, gastrointestinal bleeding in clinical before being laboratory confirmed. In addition,they appeared CRP elevated(65.08%), platelet decline(76.19%), and BG rosen(82.54%) in laboratory examination. The main IFI type was sepsis(77.14%), and the main pathogenic types were candida parapsilosis(36.51%), candida albicans(26.98%), candida guilliermondii(23.81%). About risk factors, the broad spectrum antibiotic exposure rate was 100%, the parenteral nutrition exposure rate was 93.65%, the mechanical ventilation was 92.06%, the central venous catheter was 60.32%. Fluconazole or voriconazole is effective for most fungal septicemia, and fluconazole and amphotericin B combination therapy is needed by CNS fungal infection. The infants with fungal infection was with high mortality rate(6.35%) and poorly prognosis.Conclusion The invasive fungal infection rate in our NICU was higher, and premature and low birth weight neonates are at higher risk, so the IFI should be monitored carefully and exactly, diagnosed early and treated early.Part 4 The study of ventilator-associated pneumoniaObjective To research the occurrence situation of ventilator associated pneumonia(VAP for short), provide reference for clinical diagnosis and treatment.Method Adopt the method of retrospective study to collected clinical data of all neonates with mechanical ventilation more than 48 hours in our NICU between January 2009 and December 2009, and analysis the incidence of VAP in five years and the change trend, pathogenic bacteria distribution, drug susceptibility characteristics of common pathogens and change trend.Results In this study, 462 cases used mechanical ventilation more than 48 h, and 111 cases developed VAP, the infection of VAP was 33.20 episodes per 1000 ventilator days(111/3343). Children with gestational age, the incidence of VAP is different, the smaller the gestational age is, the higher the incidence of VAP is. VAP was mainly caused by acinetobacter baumannii(38.04%) and klebsiella pneumoniae(27.17%). Acinetobacter baumannii was sensitive to amikacin, tobramycin and minocycline, resistant to the cephalosporin class antibiotic. ESBL(+)pneumonia klebsiella was sensitive to imipenem and meropenem, ESBL(?) klebsiella pneumoniae was sensitive to amikacin, gentamicin and SMZco. Single factor analysis showed that related factors of VAP included the duration days of mechanical ventilation, VAP extubation after intubation, PICC, IVIG and antibiotic using before VAP. Further Logistic regression analysis found that duration days of mechanical ventilation and the use of antibiotics prior to VAP were independent risk factors for VAP.Conclusion VAP infection rate was 33.20 per 1000 ventilator days, the smaller the gestational age, the higher the incidence of VAP. We should try to shorten the duration of mechanical ventilation, using antibiotics rationally, in order to control the occurrence of VAP.