Predictors of mortality in Acinetobacter baumannii bacteremia

Abstract

Objective: We aimed to describe the risk factors for fatality among the patients with Acinetobacter baumannii bacteremia. Methods: Patients with a positive blood culture for A. baumannii by BacT/Alert (bioMerieux, Durham, NC) system were selected. Surviving and nonsurviving patients were compared in terms of demographic characteristics, underlying diseases, invasive procedures, and antibiotic resistance of the microorganisms. Therapies were evaluated according to the results of antibiotic susceptibility tests, and impact of inappropriate therapies for A. baumannii bacteremia was evaluated statistically. Results: of the 40 patients enrolled, 21 (52.5%) died due to A. baumannii bacteremia. Univariate analysis of risk factors for fatality revealed the following parameters to be significant: > 50 years of age, an APACHE II score > 16, and transfer from one unit to another more than once (p<0.05). Cox regression survival analysis demonstrated that the death rate was 3.5 times higher in the patients older than 50 years of age, and 2.8 times higher in the patients with an APACHE II score > 16. Overall imipenem resistance in A. baumannii was 67.5%, and carbapenem resistance among fatal cases was 76%. When the antibiotic sensitivity results were assessed, it was noted that 70% of the patients had been receiving inappropriate therapy. However, the antibiotic therapy received or initiated empirically was not shown to be a significant risk factor for mortality (p>0.05). Conclusions: Knowing the risk factors that indicate mortality in such patients and ensuring early diagnosis are of critical importance with respect to prognosis. Starting appropriate therapy by making the right decisions regarding the severity of acute and underlying conditions will have favorable effects on the management of A. baumannii bacteremia.