Carbapenem resistance and mortality in patients with Acinetobacter baumannii infection: systematic review and meta-analysis

Abstract

Acinetobacter baumannii has emerged as a major cause of healthcare-associated infections. Controversy exists as to whether antimicrobial resistance increases the risk of mortality. We conducted a systematic review and meta-analysis to examine this association. We searched MEDLINE and EMBASE databases up to May 2013 to identify studies comparing mortality in patients with carbapenem-resistant A. baumannii (CRAB) vs. carbapenem-susceptible A. baumannii (CSAB). A random-effects model was used to pool Odds Ratios (OR). Heterogeneity was examined using I(2). We included 16 observational studies. There were 850 reported deaths (33%) among the 2546 patients. Patients with CRAB had a significantly higher risk of mortality than patients with CSAB in the pooled analysis of crude effect estimates (crude OR = 2.22; 95% CI = 1.66, 2.98), although substantial heterogeneity was evident (heterogeneity I(2) = 55%). The association remained significant in the pooled adjusted OR of 10 studies. Studies reported that patients with CRAB compared to patients with CSAB were more likely to have severe underlying illness and also to receive inappropriate empirical antimicrobial treatment, which increases the risk of mortality. Our study suggests that carbapenem resistance may increase the risk of mortality in patients with A. baumannii infection. However, cautious interpretation is required because of the residual confounding factors and inadequate sample size in most studies.

Comparison of the efficacy of colistin monotherapy and colistin combination therapies in the treatment of nosocomial pneumonia and ventilator-associated pneumonia caused by Acinetobacter baumannii

“…In A. baumannii infections resistant to carbapenem, mortality is higher than those with susceptibility to carbapenem. [12] The present study also found higher mortality in patients who received colistin-carbapenem combination. This increased mortality may have resulted either from the failure to achieve the desired synergistic effect after administration to severely infected patients or from the addition of infections by other resistant microorganisms developing under carbapenem.…”

“…[1,11,12] Pneumonia is the most common type of infection; its mortality rate can increase up to 65% [4,13] when attributed to MDR-AB. In our ICU, the mortality rate was 83.6% in 134 patients with MDR-AB-associated pneumonia/VAP.…”

Significant spread of extensively drug-resistant Acinetobacter baumannii genotypes of clonal complex 92 among intensive care unit patients in a university hospital in southern Iran

“…This resistance includes non-susceptibility to carbapenems, and hence the bacteria are called carbapenem-resistant A. baumannii (CRAB). The appearance of CRAB has substantially reduced the numbers of antibiotics available for treatment, and patients with CRAB infections have a significantly higher risk of mortality [3]. The global occurrence of CRAB is an escalating public health challenge, especially in South and Southeast Asia, where such strains are becoming one of the predominant nosocomial pathogens [4].…”

Efficacy of nebulized colistin-based therapy without concurrent intravenous colistin for ventilator-associated pneumonia caused by carbapenem-resistant Acinetobacter baumannii

“…Carbapenem resistance in Acinetobacter baumannii (CRAB) infection has become increasingly prevalent worldwide and has been associated with high mortality rate (1)(2)(3). Patients with ventilator-associated pneumonia (VAP) caused by carbapenem-resistant CRAB, the incidence of which has been rising substantially, may be predisposed to poor outcome because of limited therapeutic options and the likelihood of inappropriate empirical antibiotic therapy (4,5).…”