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

BackgroundIt 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.MethodsThis 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.ResultsA 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).ConclusionRisk 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.