Risk Factors for Mortality in Patients with Pseudomonas aeruginosa Bacteremia: Clinical Impact of Antimicrobial Resistance on Outcome

Abstract

Despite the high prevalence of antimicrobial resistance among Pseudomonas aeruginosa bacteremia, the clinical consequence of resistance remains unclear. The purpose of this study was to identify predictors of mortality and evaluate the clinical impact of antimicrobial resistance on outcome in P. aeruginosa bacteremia. A retrospective cohort study including patients with P. aeruginosa bacteremia was performed. The risk factors for antimicrobial resistances were evaluated, and the impact of the respective resistances on mortality was assessed. Of 202 P. aeruginosa bacteremia cases, the resistance rates to ceftazidime, piperacillin, imipenem, fluoroquinolone, and aminoglycoside were 36.6%, 22.3%, 22.8%, 23.8%, and 17.8%, respectively. A prior use of fluoroquinolones and an indwelling urinary catheter were common risk factors for all types of antimicrobial resistance. The overall 30-day mortality rate was 25.2% (51/202), and the risk factors for mortality were corticosteroid use, nosocomial acquisition, polymicrobial infection, an increasing Charlson's weighted co-morbidity index, and intensive care unit care (p < 0.05). As compared with the susceptible group, ceftazidime-, piperacillin-, or imipenem-resistant groups had a higher mortality (p < 0.05). A multivariate analysis showed that resistance to ceftazidime or imipenem remained a significant factor associated with mortality (odds ratio, 2.96; 95% confidential interval, 1.20-7.31; and odds ratio, 2.74; 95% confidential interval, 1.02-7.31, respectively). Antimicrobial resistance, especially to ceftazidime or imipenem, adversely affected outcome in patients with P. aeruginosa bacteremia.

Retrospective Analysis of Antibiotic Susceptibility Patterns of Respiratory Isolates of Pseudomonas Aeruginosa in a Chest Diseases Public Hospital

“…This rate was reported as 51.1% in the study of Pinheiro et al (27) and 25.2% in the study of Joo et al (31). The reason for lower mortality in our study than in other studies is that those studies were conducted among intensive care patients or patients with bacteremia.…”

Increased risk of death with recurrent Pseudomonas aeruginosa bacteremia

“…The occurrence of primary P. aeruginosa BSI infections in the hematology population is well described [12][13][14]. High rates of corticosteroid use were also described in the P. aeruginosa primary BSI cohort described by Joo et al [15]. Thus these two variables place an individual at risk for not only a primary BSI but also for its recurrence.…”

Influence of Multidrug Resistance and Appropriate Empirical Therapy on the 30-Day Mortality Rate of Pseudomonas aeruginosa Bacteremia

“…Some authors have identified resistance to ceftazidime, carbapenems, or MDR as risk factors for mortality (1,7,16,24,25,28). In contrast, Combes et al (3) evaluated the impact of piperacillin resistance on the outcomes of P. aeruginosa ventilator-associated pneumonia in patients who received appropriate empirical antibiotics, and they found that piperacillin resistance was not associated with higher mortality.…”

“…However, the influence of multidrug resistance on the probability of receiving appropriate empirical therapy was not evaluated. Some authors have described a higher mortality rate among patients with MDR strains (1,7,8,10,16,25,28), but these patients more frequently received incorrect empirical therapy and had more severe underlying diseases and longer hospital stays than patients infected by susceptible Pseudomonas aeruginosa strains (24). Therefore, the individual influence of each one of these variables on the mortality of PAB is still not well defined.…”