Potential interventions for an antimicrobial stewardship bundle for Escherichia coli bacteraemia.

Introduction: Escherichia coli is the most commonly identified bacteraemia, and causes a broad spectrum of diseases. The range of clinical conditions associated with E. coli bacteraemia mean that antimicrobial therapy is highly variable. This study aimed to determine the workload, efficiency and potential impact of an antimicrobial stewardship (AMS) bundle approach to E. coli bacteraemia.

Methods: An observational cohort study of patients with E. coli bacteraemia was performed, and a review of each case's entire medical record was undertaken. A number of AMS interventions were modelled on this cohort to assess their impact on overall days of antimicrobial therapy and time to optimized antimicrobial therapy.

Results: In total, 566 episodes of E. coli bacteraemia were identified. A number of AMS interventions were modelled to assess their impact. The strict implementation of guideline-based therapy was found to increase the number of patients receiving ineffective empirical therapy to 38/266 (14.3%) compared with 27/266 (10.2%) patients when w hen non-guideline-adherent therapy was allowed. A scheduled review by an AMS team on day 3 of empirical therapy could lead to a narrower-spectrum intravenous antibiotic in 237/515 (46%) cases, and 386 cases (68.2% of cohort) could have their duration of therapy reduced by a median of 7 days.

Conclusion: This study provides detailed description of a large cohort of patients with E. coli bacteraemia. There remains significant variability in empirical treatment, choice of step-down therapy and antimicrobial duration. A significant opportunity exists for AMS programmes to impact the management of E. coli bacteraemia through a bundled approach.