Analysis Of Clinical Characteristics And Risk Factors For Nosocomial Lower Respiratory Tract Infection By Acinetobacter Baumannii

Objective To investigate the clinical features,antibiotic resistance and risk factors for nosocomial lower respiratory tract infection by Acinetobacter baumannii,which aims at providing references and bases for further clinical diagnosis and treatment on the lower respiratory tract infection.Methods The complete clinical data were chosen and analyzed retrospectively from 80 patients,as an infection group,with lower respiratory tract infection by Acinetobacter baumannii hospitalized at the First Affiliated Hospital of Anhui Medical University between June 1st 2014 and October 1st 2015.In strict accordance with the 1: 1 matching principle,another 80 patients with hospitalized in the same time without lower respiratory tract Acinetobacter baumannii infection were set as a control group,whose clinical characteristics.were retrospectively analyed.The susceptibility and drugresistance of 80 strains of Acinetobacter baumannii to 15 kinds of antimicrobial agents was detected by standard Kirby-Bauer method.The risk factors of lower respiratory tract infection with Acinetobacter baumannii were obtained by the case-control study and conditional logistic regression.Results1.A total of 80 patients with nosocomial lower respiratory tract infection by Acinetobacter baumannii consisted of 57 males and 23 females,aged from 14 to 94 years old,average age 62.51±17.45 years old,the mean days of hospitalization was 39.13 ± 25.47 days.Before the patients infected by Acinetobacter baumannii,the average days of hospitalization was 5.54±3.60 days.Before the patients infected by Acinetobacter baumannii,their average APACHE?scores was 22.31±6.56 points.The most common primary diseases in infection group were composed of 26 cases cerebrovascular accident(including cerebral hemorrhage,cerebral infarction,et al)(32.50%,26/80),11 cases of cardiovascular system disease(13.75%,11/80),8 cases of respiratory system disease(10.00%,8/80).71 patients with lower respiratory infection by Acinetobacter baumannii were identified in the intensive care unit(ICU),accounted for88.75%(71/80).Nearly half(41.25%,33/80)patients of nosocomial lower respiratory tract infection by Acinetobacter baumannii had other site infections with bacterial and/or fungal.20%(16/80)patients merged with other sites of Acinetobacter baumannii infection.37.5%(30/80)patients in infection group had died,despite positive treatment and all rescue measures had implemented.2.The antibiotic susceptibility and drug-resistance tests showed that minocycline(19.30% drug-resistance)and tigecycline(21.15% drug-resistance)were the lowest resistance against Acinetobacter baumannii,the followed by amikacin(54.93%drug-resistance)and cefoperazone-sulbactam(57.89% drug-resistance).The drug-resistance rate of Acinetobacter baumannii to imipenem and meropenem were96.61% and 96.92% respectively.The resistant rates of other testing drugs were more than 70.00%.The detection rates of multidrug-resistant(MDR),extensively drug resistant(XDR)against Acinetobacter baumannii were 66.25%(53/80)and27.50%(22/80),respectively.3.The univariate analysis performed by 10 risk factors probably related to the lower respiratory tract infection with Acinetobacter baumannii and multivariate conditional logistic regression analysis showed that the independent risk factors of lower respiratory tract infection by Acinetobacter baumannii were long-term ICU stay(?5day)(OR=13.868,95%CI 1.376-139.775,P=0.026),mechanical ventilation use (OR=36.325,95%CI 2.033-649.090,P=0.015),the Apache II score?20(OR=37.821,95%CI 2.378-601.600,P=0.010),combined use of antibiotics(OR=15.652,95%CI1.1020-222.481,P=0.005)(P<0.05).Conclusions1.Most infection of Acinetobacter baumannii in lower respiratory tract occurred in ICU,which closely related to the central nervous system diseases.If the patients had severe primary disease with multi-site infection,their prognosis were very poor.In order to prevent the incidence of nosocomial lower respiratory tract caused by Acinetobacter baumannii infection,infection management and medication monitoring should be strengthened in whole hospital,especially in ICU and the department of neurosurgery.2.The drug-resistance of nosocomial Acinetobacter baumannii infection situation was grim and the resistance to carbapenems was very serious,which showed the trend of multidrug or extensively drug resistance,which should be treated with PK/PD theory,the early reasonable use of antibiotics,the timely adjustment of antibiotics based on antibiotic susceptibility and drug resistance testing should be considered.3.The long-term ICU stay(?5day),use of mechanical ventilation,the Apache II score?20,combination use of antibiotics were the risk factors for nosocomial lower respiratory tract infection by Acinetobacter baumannii.Clinicians should pay attention to these factors,nosocomial infection should strengthen be monitored,to prevent the occurrence of Acinetobacter baumannii infection in the lower respiratory tract.