Risk Factors for Mortality in Patients with Carbapenem-Resistant Acinetobacter baumannii Bacteremia: Impact of Appropriate Antimicrobial Therapy

Abstract

This study investigated predictors associated with 14-day mortality, and focused especially on the impact of appropriate antimicrobial treatment among patients with carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia. This retrospective study was performed at a tertiary care hospital in Korea from June 2007 to June 2010. Antibiotic therapy was considered appropriate if the antibiotics were administered via an appropriate route within 24 hr after the result of blood culture, had in vitro sensitivity to isolated strains, and of an adequate dosage according to the current guidelines. Ninety-five patients with A. baumannii bacteremia were included; of these, 53 (55.8%) were infected with CRAB. The overall infection-related 14-day mortality was higher in patients receiving inappropriate antimicrobial therapy than in patients receiving appropriate therapy (59.5% [22/37] vs 13.8% [8/58], P < 0.05). Multivariate analysis showed that septic shock (OR 10.5, 95% CI, 1.93-57.4; P = 0.006), carbapenem-resistance (OR 7.29, 95% CI 1.57-33.8; P = 0.01), pneumonia as a source of bacteremia (OR 5.29, 95% CI 1.07-26.1; P = 0.04), and inappropriate antimicrobial therapy (OR 8.05, 95% CI 1.65-39.2; P = 0.009) were independent risk factors for 14-day mortality. Early definite antimicrobial therapy had an influence on favorable outcomes in patients with A. baumannii bacteremia.

Molecular Characterization of Carbapenem Resistant Acinetobacter baumannii in Cancer Patients

“…Similar high 14-day mortality rates were previously recorded with Acinetobacter infections (Kim et al, 2012). Still the exact cause of mortality is not clear as these infections usually occur in high risk ICU patients with high rates of comorbidity.…”

“…In addition, 48.8% of A. baumannii infections were isolated from patients admitted to ICU. The importance of Acinetobacter species as a cause of ICU infections was previously confirmed (Kim et al, 2012).…”

“…The isolate was considered as MDR, if resistant to more than two classes of antimicrobials (≥ 3 classes) (Vaze et al, 2013). Carbapenem resistant Acinetobacter isolates were defined as non-susceptible or with diminished susceptibility to meropenem and/or imipenem in vitro (Kim et al, 2012). Fourteen-day in hospital mortality after the onset of Acinetobacter infection was used as the main assessment of patients' outcome.…”

Treatment Options for Carbapenem-Resistant and Extensively Drug-Resistant Acinetobacter baumannii Infections

“…Independent risk factors for mortality among patients with carbapenem-resistant A. baumannii bloodstream infections include the severity of illness, underlying malignancy, history of transplant, higher age, septic shock, concurrent pneumonia, inappropriate antimicrobial therapy, prolonged ICU stay, and renal failure, among others [19, 20, 22–25]. High mortality rates observed in patients with carbapenem-resistant A. baumannii infection are believed to be mostly due to the greater severity of illness and higher risk of receiving early inappropriate antimicrobial therapy (see “Importance of early appropriate therapy”) [18].…”

Emergence of Carbapenem Resistant Non-Fermenting Gram-Negative Bacilli Isolated in an ICu of a Tertiary Care Hospital

“…The rate of carbapenem resistance in NFGNB is gradually increasing worldwide and vary geographically [4,5]. Mechanism of carbapenem resistance in non-fermenting Gram-negative bacilli occurs by various mechanisms including carbapenemase production, decrease permeability due to loss of porin channels, overexpression of efflux pump and changes in penicillin binding proteins [6].…”