Risk factors and clinical outcomes of patients with carbapenem-resistant Acinetobacter baumannii bacteremia.

BACKGROUND: It is still controversial whether carbapenem-resistant Acinetobacter baumannii (CRAB) is an independent risk factor for mortality. This study aimed to determine the risk factors and outcomes of patients with CRAB bacteremia, compared to those with carbapenem-susceptible A. baumannii (CSAB) bacteremia. METHODS: This retrospective cohort study was conducted in Taipei Veterans General Hospital, Taiwan. Patients with bacteremia due to A. baumannii during June 2002 and December 2007 were included. RESULTS: A total of 62 patients with CRAB and 164 with CSAB bacteremia were included. Among these patients, the independent risk factors for acquiring CRAB bacteremia were hematological malignancy [odds ratio (OR): 4.04; 95% confidence interval (CI): 1.29-12.70; p = 0.017], previous use of cefepime (OR: 2.60; 95% CI 1.11-6.08; p = 0.028) and use of total parenteral nutrition (OR: 3.06; 95% CI 1.12-8.39; p = 0.029). The patients with CRAB bacteremia had higher mortality rate than those with CSAB bacteremia. However, multivariate analysis showed that among patients with A. baumannii bacteremia, acquisition of CRAB by itself was not an independent risk factor for 14-day mortality. Instead, the independent factors predicting14-day mortality were Acute Physiology and Chronic Health Evaluation (APACHE) score > 20 (OR: 6.33; 95% CI: 2.32-17.26; p < 0.001), shock (OR: 2.68; 95% CI: 1.11-6.23; p = 0.025) and inappropriate antimicrobial therapy (OR: 2.14; 95% CI: 1.01-4.53; p = 0.046). CONCLUSION: Risk factors for CRAB bacteremia were hematological malignancies, previous use of cefepime and use of total parenteral nutrition. Acquisition of CRAB itself is not a poor prognostic factor for the patients with A. baumannii bacteremia.

Predictors of mortality in surgical patients with Acinetobacter baumannii bacteremia.

BACKGROUND: Acinetobacter baumannii has emerged as an important pathogen of nosocomial infection. The aim of this study was to evaluate the predictors of poor outcome in surgical patients with A baumannii bacteremia. METHODS: We retrospectively recruited a total of 50 patients who developed A baumannii bacteremia within 2 weeks after surgery during a 113-month period. The primary outcome for this study was all-cause 14-day mortality. Clinical and laboratory data, antimicrobial susceptibility, treatment, and Sequential Organ Failure Assessment (SOFA) score were evaluated as possible predictors of outcome. RESULTS: The 14-day mortality was 20% and there was no association between type of surgery and mortality. The SOFA score was the only independent predictor of 14-day mortality after adjustment for other variables. The calibration was acceptable (Hosmer-Lemeshow χ(2) = 3.65, p = 0.72) and the discrimination was good (area under the receiver operating characteristic curve: 0.80 ± 0.07, 95% confidence interval, 0.67-0.94). We found that a SOFA score ≥ 7 was a significant predictor of 14-day mortality in surgical patients with A baumannii bacteremia. CONCLUSIONS: The SOFA score assessed at the onset of bacteremia is a reliable tool for predicting 14-day mortality in surgical patients with A baumannii bacteremia.