LAUSR

INTRODUCTION Escherichia coli (E. coli) is the most commonly identified bacteraemia, and causes a broad spectrum of illness. The range of clinical conditions associated with E. coli bacteraemia mean antimicrobial therapy is highly variable. We aim to determine the workload, efficiency and potential impact of an antimicrobial stewardship (AMS) bundle approach to E. coli bacteraemia. METHODS We performed an observational cohort study of patients with E. coli bacteraemia, and a review of each case's entire medical record was undertaken. We then modelled a number of AMS interventions on this cohort to assess their impact on overall days of antimicrobial therapy and time to optimized antimicrobial therapy. RESULTS 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 non-effective empirical therapy, from 27/266 patients given non-guideline adherent therapy (10.2%) to 38/266 (14.3%). A scheduled review by an AMS team at day 3 of empirical therapy could lead to a narrower-spectrum intravenous antibiotic in 237/515 (46%) of cases. 386 cases (68.2% of cohort) could have their duration of therapy reduced by a median of 7 days. CONCLUSION This study provides a 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 programs to impact the management of E. coli bacteraemia management through a bundled approach.