Effect of adequate single-drug versus combination antimicrobial therapy on mortality in Pseudomonas aeruginosa bloodstream infections. A post hoc analysis of a prospective cohort.
Clin Infect Dis. 2013 Apr 11;
Authors: Peña C, Suarez C, Ocampo-Sosa A, Murillas J, Almirante B, Pomar V, Aguilar M, Granados A, Calbo E, Rodríguez-Baño J, Rodríguez F, Tubau F, Oliver A, Martínez-Martínez L, for the Spanish Network for Research in Infectious Diseases (REIPI)
Background. Empirical combination therapy is recommended for patients with known or suspected Pseudomonas aeruginosa (PA) infections as a means to decrease the likelihood of administering inadequate antimicrobial treatment, to prevent the emergence of resistance, and to achieve a possible additive or even synergistic effect. Methods. We performed a post-hoc analysis of patients with PA bloodstream infections from a published prospective cohort. Mortality was compared in patients treated with adequate empirical and definitive combination therapy (AECT, ADCT), and adequate empirical and definitive single-drug therapy (AESD, ADSD). Confounding was controlled by Cox regression analysis, and a propensity score for receiving AECT or ADCT was also used. Results. The final cohort comprised 593 patients with a single episode of PA bacteremia. The 30-day mortality was 30% (176 patients); 76 patients (13%) died during the first 48 hours. The unadjusted probabilities of survival until day 30 were 69.4% (95% confidence interval [CI]: 59.1-81.6) for the patients which receiving AECT, 73.5% (95% CI: 68.4-79.0) for the AESD group, and 66.7% (95% CI: 61.2-72.7) for patients who received inadequate empirical therapy (P=0.17, log-rank test). After adjustment for confounders, the AESD group (adjusted hazard ratio [aHR]: 1.17; 95%CI: 0.70-1.96; p=0.54) and patients who received ADSD (aHR: 1.34; 95%CI: 0.73-2.47 p=0.35) showed no association with 30-day mortality compared with the AECT and ADCT groups respectively. Conclusions. These results suggests that treatment with combination antimicrobial therapy did not reduce the mortality risk compared with single-drug therapy in PA bloodstream infections.
PMID: 23580739 [PubMed - as supplied by publisher]