Risk factors for mortality among patients with Pseudomonas aeruginosa bacteremia – retrospective multicenter study

Abstract Objective: To evaluate risk factors for 30-day mortality among hospitalized patients with Pseudomonas aeruginosa bacteremia, a highly fatal condition. Patients and Methods: Retrospective study conducted in 25 centers, 9 countries, including 2396 patients between January 1, 2009, through October 31, 2015. Univariable and multivariable analyses of risk factors were conducted for the entire cohort and for patients surviving >= 48 hours. Propensity score for predictors of appropriate empirical therapy was introduced into the analysis. Results: Of 2396 patients included, 636 patients died within 30 days (26.5%). Significant predictors of mortality in multivariable analysis included patient related factors: age (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.03), female gender (OR 1.34, 95% CI 1.03-1.77), functional capacity: bedridden (1.99, 1.24-3.21), recent hospitalization (1.43, 1.07-1.92), concomitant corticosteroids (1.33, 1.02-1.73), and Charlson comorbidity score (1.05, 1.01-1.93). Infection related factors were: multidrug resistant Pseudomonas (1.52, 1.15-2.1), non-urinary source (2.44, 1.54-3.85), and Sequential Organ Failure Assessment (SOFA) score (1.27, 1.18-1.36). Inappropriate empirical therapy was not associated with increased mortality (0.81, 0.49-1.33). Among 2135 patients surviving 48 hours, hospital acquired infection (1.59, 1.21-2.09), baseline endotracheal tube (1.63, 1.13-2.36), and intensive care unit admission (1.53, 1.02-2.28) were additional risk factors. Conclusion: Risk factors for mortality among patients with P. aeruginosa were mostly irreversible. Early appropriate empirical therapy was not associated with reduced mortality. Further research should be conducted to explore sub-groups that may not benefit from broad spectrum antipseudomonal empirical therapy. Efforts should focus on prevention of infection, mainly hospital acquired infection and multidrug resistant pseudomonal infection.