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

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.