191. Appropriateness of Empiric Antibiotics for Enterobacteriaceae Bacteremia

BACKGROUND: Appropriate empiric antibiotic therapy is associated with decreased mortality and recurrence in patients with Enterobacteriaceae bacteremia (EB). Increasing bacterial resistance adds an additional layer to this complex clinical scenario. Swift utilization of appropriate antibiotics is crucial for improved patient outcomes. However, prolonged and excessively broad antibiotic coverage is not without its own complications. Our study aimed to review the appropriateness of empiric antibiotics for EB. METHODS: A retrospective chart review of all patients >18 years of age who were admitted to a single academic community hospital during 2018 EB anytime throughout their hospitalization. The primary endpoint was the appropriateness of empiric antibiotic therapy, defined as receiving active therapy prior to the return of antimicrobial sensitivities that were susceptible to the empiric agents used. Appropriateness was further adjusted for standard of care (SOC) practices. Specifically, despite in vitro susceptibility of piperacillin/tazobactam and cefepime, carbapenem therapy is preferred for ESBL infections. RESULTS: Our study identified 178 patients with EB. Most common organisms included E.coli (64.6%), K. pneumoniae (11.8%) and P. mirabilis (7.3%). Resistance patterns included 1 CRE (0.57%) and 17 ESBL (9.7%) isolates. Most common sources of infection included urinary (63.5%) and intraabdominal (13.5%). Based on the sensitivity reports of tested isolates, 83.7% of patients received appropriate empiric antibiotics. After adjustment for SOC, 11.8% of ESBL patients (2/17) and 0% of CRE (0/1) patients received appropriate therapy. Comparatively 89.0% of patients without ESBL or CRE (137/154) received appropriate care (P < 0.0001). CONCLUSION: The results of this study demonstrate that across our patient population, over 80% of patients received appropriate empiric antibiotics for EB; however, this percentage was dramatically lower for patients with ESBL or CRE infections. This highlights room for improved rapid diagnosis and identification of risk factors predisposing to resistant organisms thereby decreasing the time to appropriate antibiotic therapy. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.