133. Creation of an Emergency Department (ED)-Specific Urine Antibiogram and Evaluation of Urinary Tract Infection (UTI) Prescribing Practices at a Tertiary Academic Medical Center

Abstract Background Inpatient settings have been the focus of most antimicrobial stewardship (AS) practices; however, the Joint Commission has now published requirements for accredited ambulatory healthcare organizations to implement AS. This analysis aimed to create a urine isolate antibiogram and to evaluate microbiological data and prescribing practices for UTI patients in the ED. Methods This retrospective cohort study included adults admitted to either of two EDs at University of Minnesota Medical Center and diagnosed with a UTI between 1/1/2018 and 12/31/2018. Patients were excluded if subsequently admitted to an inpatient unit or if they had a repeat culture growing the same organism as the index isolate. Diagnosis of cystitis versus pyelonephritis was based on ICD-10 coding. Data including urinalysis and culture results, susceptibilities, empiric antibiotic selection, and readmissions were collected. Results Data from 350 isolates were collected for inclusion in the antibiogram. Patient characteristics corresponding to this isolate collection included 78.9% female, median age of 41 years, and 64.6% diagnosed with pyelonephritis. Escherichia coli was the most common organism (70%), followed by Klebsiella pneumoniae (5.4%) and Proteus mirabilis (4%). Combined susceptibilities of E. coli isolates from both EDs were: 49.4% ampicillin, 55.7% ampicillin/sulbactam, 69.8% sulfamethoxazole/trimethoprim, 83.7% ciprofloxacin (CIP), 85.7% cefazolin, 93.9% ceftriaxone, and 94.3% nitrofurantoin (NIT). The most common discharge antibiotics prescribed for cystitis patients were NIT (29.8%) and cephalexin (25%). Pyelonephritis patients were most frequently prescribed CIP (32.3%) and cefdinir (14.2%). Drug-bug mismatches occurred in 19.1% of patients (10.5% cystitis vs. 23.9% pyelonephritis). The rates of ED readmission within 96-hours and inpatient admission within 30 days, for any reason, were 4.3% and 9.1% respectively. Conclusion Based on the ED-specific urine antibiogram generated, NIT (cystitis) and CIP (pyelonephritis) could be considered first-line agents for empiric treatment of UTI at our institution. Drug-bug mismatches were more common in pyelonephritis patients. These data will be used to develop a treatment algorithm aimed at improving treatment of UTI in the ED. Disclosures Elizabeth B. Hirsch, PharmD, Merck (Grant/Research Support)Nabriva Therapeutics (Advisor or Review Panel member)