Analysis Of Clinical Manifestations And Risk Factors Of Mortality Of Acinetobacter Baumannii Bloodstream Infection

Background and objectiveAcinetobacter baumannii is a gram-negative bacilli, and widespread in nature、 the hospital environment. Genome research found that it has strong resistance and clone propagation ability, at present, multidrug-resistant、 extensivelydrug-resistant and even pandrug-resistant Acinetobacter baumannii present world epidemic. It has become the world’s major challenge in the field of anti-infective, and is one of the most important pathogenic bacteria of nosocomial infection in our country. Acinetobacter baumannii most often causes infection of lower respiratory tract infections, especially ventilator-associated pneumonia, followed by bloodstream infections. Acinetobacter baumannii bloodstream infections often occur in critically ill patients, once happen, will threat to the patient’s life, the prognosis is very poor.The antibiotics commonly used for Acinetobacter baumannii includ:sulbactam> carbapenem、polymyxin、tigecycline、quinolones、tetracydines and aminoglycosides. But the treatment decision especially for multidrug-resistant Acinetobacter baumannii infections is still a great difficulty. In recent years, there are a large number of in vitro antibacterial activity and animal models of researchs and observations, but the drug combination therapy clinical researchs for multidrug-resistant Acinetobacter baumannii has not been implemented. Therefore, understanding the inducing factors of Acinetobacter baumannii bloodstream infections, the risk factors of mortality and the antimicrobial treatment strategies is of great significance to identify high-risk patients and reduce the mortality.This study was to explore the clinical manifestations of Acinetobacter baumannii bloodstream infections、the risk factors of mortality, antimicrobial therapy and its relationship with prognosis.MethodsClinical data from 153 patients with Acinetobacter baumannii bloodstream infection hospitalized in First Affiliated Hospital of Zhejiang University from January 2013 to September 2014 were analyzed retrospectively. According to the 28-day prognosis after admission, the patients were divided into non-survivors(n=76)and survivors (n=77). Data on demographic and clinical characteristics, underlying diseases, treatments, invasive procedures, bacterial resistance to antibiotics, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ)score on set, and antimicrobial therapy were collected. The index as an independent risk factor of mortality was demonstrated by multivariate logistic regression analysis.Results(1) This study included 153 patients with Acinetobacter baumannii bloodstream infection, and the 28-day mortality was 49.7%.(2) The independent risk factors of mortality were APACHE Ⅱ score>22 on set [odds ratio (OR)=15.7,95% confidence interval(95% CI)5.1-48.1, P<0.001], septic shock(OR=6.3,95% CI 1.9-21.3, P=0.003), and receipt of steroids (OR=3.6,95% CI为1.0-12.3, P=0.043).(3)Compared with subjects treated with non-cefoperazone-sulbactam-based regimen, those treated with cefoperazone-sulbactam-based regimen for multidrug-resistant Acinetobacter baumannii(MDR-AB)had significantly lower mortality of 7-day、14-day and 28-day(P<0.001, P<0.001、P=0.002). The mortality of carbapenem single drug use group was up to 76.3%, and was significantly higher than other three groups, the difference was statistically significant (P< 0.001、0.027、0.019).Conclusion(1) The patients with Acinetobacter baumannii bloodstream infection had high mortality.(2) Receipt of steroids was associated with increased mortality of patients with Acinetobacter baumannii bloodstream infection; Septic shock and APACHEⅡ score≥22 on set predicted adverse outcome.(3) Cefoperazone-sulbactam-based antimicrobial therapy can improve the prognosis of patients with Acinetobacter baumannii bloodstream infection.