Impact of carbapenem resistance and receipt of active antimicrobial therapy on clinical outcomes of Acinetobacter baumannii bloodstream infections.

Authors

Esterly JS, Griffith M, Qi C, et al. 

Institution

Department of Pharmacy Practice, Chicago State University College of Pharmacy, Chicago, Illinois, USA.

Source

Antimicrob Agents Chemother 2011 Oct; 55(10) :4844-9.

Abstract

Nosocomial Acinetobacter baumannii bloodstream infections occur with significant prevalence and mortality. The relationship between carbapenem resistance in A. baumannii and patient outcomes remains unclear. A retrospective cohort study was conducted on patients with A. baumannii bacteremia. Outcomes, controlling for confounders, were compared for carbapenem-nonresistant A. baumannii (CNRAB) and carbapenem-resistant A. baumannii (CRAB). The primary outcome studied was all-cause hospital mortality, and the secondary endpoints evaluated were time to mortality, time to negative cultures, and length of stay postinfection for survivors. A total of 79 patients, 37 infected with CRAB and 42 with CNRAB, were studied. Hospital mortality was greater in the CRAB group as determined based on bivariate analysis (P < 0.01); however, this effect was nullified when controlling for relevant confounders with logistic regression and a Cox proportional-hazards model (P = 0.71 and 0.75, respectively). Values for time to mortality and time to negative cultures did not differ between the groups. The median number of days of stay postinfection for survivors was greater for the CRAB group than the CNRAB group (14 versus 6.5; P < 0.01). Patients who received active antimicrobial therapy were less likely to die (93.5% versus 74.2%; P = 0.02), regardless of carbapenem susceptibility classifications, and this result was robust in the multivariate model (P = 0.02). Trends existed for improved outcomes in patients receiving an active beta-lactam, and patients fared worse if they had received a polymyxin as an active agent. Patients with CRAB bloodstream infections were more chronically ill and had more comorbidities. Inactive therapy was more important than carbapenem susceptibility with respect to outcomes, was a strong predictor of death, and is potentially modifiable.

Mesh

Acinetobacter Infections
Acinetobacter baumannii
Adult
Aged
Anti-Bacterial Agents
Bacteremia
Carbapenems
Cohort Studies
Cross Infection
Drug Resistance, Bacterial
Female
Hospital Mortality
Humans
Male
Microbial Sensitivity Tests
Middle Aged
Polymyxins
Retrospective Studies
Treatment Outcome
beta-Lactamases

Language

eng

Pub Type(s)

Journal Article Research Support, Non-U.S. Gov't

PubMed ID

21825287