Improvement of gram-negative susceptibility to fluoroquinolones after implementation of a pre-authorization policy for fluoroquinolone use: A decade-long experience.

OBJECTIVE: Due to concerns over increasing fluoroquinolone (FQ) resistance among gram-negative organisms, our stewardship program implemented a preauthorization use policy. The goal of this study was to assess the relationship between hospital FQ use and antibiotic resistance. DESIGN: Retrospective cohort. SETTING: Large academic medical center. METHODS: We performed a retrospective analysis of FQ susceptibility of hospital isolates for 5 common gram-negative bacteria: Acinetobacter spp., Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Primary endpoint was the change of FQ susceptibility. A Poisson regression model was used to calculate the rate of change between the preintervention period (1998-2005) and the postimplementation period (2006-2016). RESULTS: Large rates of decline of FQ susceptibility began in 1998, particularly among P. aeruginosa, Acinetobacter spp., and E. cloacae. Our FQ restriction policy improved FQ use from 173 days of therapy (DOT) per 1,000 patient days to <60 DOT per 1,000 patient days. Fluoroquinolone susceptibility increased for Acinetobacter spp. (rate ratio [RR], 1.038; 95% confidence interval [CI], 1.005-1.072), E. cloacae (RR, 1.028; 95% CI, 1.013-1.044), and P. aeruginosa (RR, 1.013; 95% CI, 1.006-1.020). No significant change in susceptibility was detected for K. pneumoniae (RR, 1.002; 95% CI, 0.996-1.008), and the susceptibility for E. coli continued to decline, although the decline was not as steep (RR, 0.981; 95% CI, 0.975-0.987). CONCLUSIONS: A stewardship-driven FQ restriction program stopped overall declining FQ susceptibility rates for all species except E. coli. For 3 species (ie, Acinetobacter spp, E. cloacae, and P. aeruginosa), susceptibility rates improved after implementation, and this improvement has been sustained over a 10-year period.

Initial management of candidemia at an academic medical center: evaluation of the IDSA guidelines.

Treatment of candidemia is more complicated because of the changing epidemiology of Candida and introduction of newer antifungal agents. Utilization and benefit of practice guidelines and infectious disease consultation for the management of candidemia has not been previously described in the routine clinical setting. We prospectively studied the impact of the Infectious Disease Society of America (IDSA) guidelines for the management of candidemia and infectious disease consultation on clinical outcomes in 119 patients with candidemia at a tertiary care hospital. Medical records were reviewed to capture data concerning use of antifungal agents, management of central venous catheters, and infectious disease consultation. Initial antifungal therapy was consistent with the IDSA guidelines in 76% of patients. Variation from the guidelines was independently associated with higher mortality (24% versus 57%, P = 0.003). Infectious disease consultation was independently associated with lower mortality (18% versus 39%, P < 0.01). Use of the IDSA guidelines and infectious disease consultation service was found to improve patient outcomes in patients with candidemia at our institution. Further studies should be performed to validate newer guidelines in a clinical setting at other institutions.

Association between vancomycin-resistant Enterococci bacteremia and ceftriaxone usage.

OBJECTIVE: Vancomycin-resistant enterococci (VRE) have become a public health concern with implications for patient mortality and costs. Hospital antibiotic usage may impact VRE incidence, but the relationship is poorly understood. Animal investigations suggest that ceftriaxone may be associated with VRE proliferation. We measured antimicrobial usage and VRE bloodstream infection (VRE-BSI) incidence to test our hypothesis that increased ceftriaxone usage would be associated with a higher incidence of VRE-BSI. DESIGN: Retrospective cohort study. SETTING: University of Alabama at Birmingham Medical Center, a 900-bed urban tertiary care hospital. PARTICIPANTS: All patients admitted during the study period contributed data. METHODS: We conducted a retrospective analysis of antimicrobial usage and VRE-BSI from 2005 to 2008 (43 months). Antimicrobial usage was quantified as days of therapy (DOTs) per 1,000 patient-days. VRE-BSI incidence was calculated as cases per 1,000 patient-days. Negative binomial regression with adjustment for correlation between consecutive observations was used to measure the association between antimicrobial usage and VRE-BSI incidence at the hospital- and care-unit levels. RESULTS: VRE-BSI incidence increased from 0.06 to 0.17 infections per 1,000 patient-days. Hospital VRE-BSI incidence was associated with prior-month ceftriaxone DOTs (incidence rate ratio, 1.38 per 10 DOTs; P = .005). After controlling for ceftriaxone, prior-month cephalosporin usage (class) was not predictive of VRE-BSI (P = .70). Similarly, prior-month usage of piperacillin-tazobactam, ceftazidime, cefepime, cefazolin, or vancomycin was not predictive of VRE-BSI when considered individually (P≥ .4 for all comparisons). The final model suggests that type of intensive care unit was related to VRE-BSI incidence. CONCLUSIONS: Ceftriaxone usage in the prior month, but not cephalosporin (class) or vancomycin usage, was related to VRE-BSI incidence. These findings suggest that an antimicrobial stewardship program that limits ceftriaxone may reduce nosocomial VRE-BSI incidence.