Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia; retrospective study of impact of combination antimicrobial therapy

Abstract

BackgroundWhether the combination of antimicrobial therapy is a factor in mortality in Pseudomonas aeruginosa bacteremia remains to be elucidated. This study investigated the risk factors for mortality in P. aeruginosa bacteremia patients and the influence of adequate antimicrobial therapy and combination therapy on clinical outcomes.MethodsThis retrospective study analyzed data of 234 patients with P. aeruginosa bacteremia at a 1,200-bed tertiary teaching university hospital in South Korea between January 2010 and December 2012. Factors associated with mortality were determined. Mortality was compared in patients with adequate empirical and targeted combination therapy, and monotherapy, and inappropriate therapy.ResultsA total of 141 (60.3%) patients were given appropriate empirical antibiotic treatment (combination therapy in 38 and monotherapy in 103). Among 183 patients (78.2%) who finally received appropriate targeted treatment, 42 had combination therapy and 141 had monotherapy. The percentage of patients receiving empirical combination therapy was slightly, but not significantly higher, in the survivor group than in the nonsurvivor group (17.0% [31/182] vs. 13.5% [7/52], p = 0.74). A similar tendency was demonstrated for targeted combination therapy (19.8% [36/182] vs. 11.5% [6/52], respectively; p = 0.31). However, in a subgroup analysis of data from patients (n = 54) with an absolute neutrophil count less than 500/mm3, the patients who had appropriate empirical or targeted combination therapy showed better outcomes than those who underwent monotherapy or inappropriate therapy (p < 0.05). Mechanical ventilation (odds ratio [OR], 6.93; 95% confidence interval [CI], 2.64–18.11; p = 0.0001), the use of a central venous catheter (OR, 2.95; 95% CI, 1.35–6.43; p = 0.007), a high Acute Physiology and Chronic Health Evaluation II score (OR, 4.65; 95% CI, 1.95–11.04; p = 0.0001), and presence of septic shock (OR, 2.91; 95% CI, 1.33–6.38; p = 0.007) were independent risk factors for 14-day mortality.ConclusionsDisease severity was a critical factor for mortality in our patients with P. aeruginosa bacteremia. Overall, combination therapy had no significant effect on 14-day mortality compared with monotherapy. However, appropriate combination therapy showed a favorable effect on survival in patients with febrile neutropenia.

Carbapenem-resistant Pseudomonas aeruginosa : association with virulence genes and biofilm formation

“…Often, bacteremia caused by P. aeruginosa resistant to antibiotics has a higher mortality rate due, in particular, to the administration of inappropriate antibiotic therapy 40 . In this study, we investigated a cohort of 157 patients with bacteremia caused by P. aeruginosa strains, with 69 of them infected by carbapenem-resistant P. aeruginosa isolates.…”

Antimicrobial resistance of selected invasive bacteria in a tertiary care center: results of a prospective surveillance study

“…In such cases, initiation of adequate antimicrobial therapy based on the most likely causative agent and its presumable susceptibility pattern in a particular medical setting is an essential step in treatment of bacteremia, and it is associated with better outcome and lower mortality [4,5].…”

WCK 5107 (Zidebactam) and WCK 5153 Are Novel Inhibitors of PBP2 Showing Potent “β-Lactam Enhancer” Activity against Pseudomonas aeruginosa, Including Multidrug-Resistant Metallo-β-Lactamase-Producing High-Risk Clones

“…These strains are responsible for a growing number of outbreaks in the hospital setting associated with significantly higher morbidity and mortality attributed to limited effective antimicrobial options (7,12,13). Of further concern, recent studies have revealed that MDR/XDR P. aeruginosa clones (such as ST111, ST175, and ST235) have disseminated in multiple institutions worldwide, and for that reason, they have been classified as epidemic high-risk clones (14)(15)(16).…”