2077. Assessment of the Clinical Impact of Rapid Identification with Same-Day Phenotypic Antimicrobial Susceptibility Testing (Accelerate Pheno™ System) on the Management of Bloodstream Infections in Adult Patients with Antibiotic Stewardship Intervention: A Retrospective Observational Study

BACKGROUND: Rapid initiation of appropriate antimicrobial therapy is crucial in managing severe infections, including bloodstream infections. Timely availability of microbiological results is essential to enable early de-escalation of empiric therapy, which is one of the key components of an effective antimicrobial stewardship program. The Accelerate Pheno™ system (AXDX) is a novel technology for rapid identification and phenotypic antimicrobial susceptibility testing with promising results. Yet the impact of this technology on the clinical management and patient outcome still is unclear. METHODS: The University Hospital Cologne is a 1,464-bed tertiary care hospital. We conducted a retrospective before and after observational study and analyzed three groups with different diagnostic and therapeutic pathways following a change in the standard of care and recent integration of AXDX: conventional microbiological diagnostics with and without antimicrobial stewardship program (ASP) intervention from January 2015 to July 2015, rapid diagnostics (AXDX in addition to conventional standard) with ASP intervention from January 2017 to March 2018. RESULTS: n = 280 patients met inclusion criteria and n = 225 (conventional microbiological diagnostics n = 74/conventional diagnostics + ASP intervention n = 79/rapid diagnostics + ASP intervention n = 72) were included in the final analysis during the two study periods. There was no difference in clinical and demographic characteristics among the three groups. The use of AXDX significantly decreased time from positive blood culture to microorganism identification (ID) (median: 25 hours vs. 12.5 hours, P < 0,001) and susceptibility testing (AST) (median: 43.8 hours vs. 17.6 hours, P < 0.001) and improved time from Gram stain to optimal therapy (median: 20.1 hours vs. 7 hours, P < 0.01). ASP intervention alone without AXDX improved the proportion of patients on optimal therapy within 48 hours after Gram stain (62.2% vs. 77.2%, P < 0.05). CONCLUSION: Use of AXDX significantly reduced time to ID and AST by 12.5/26.2 hours. In combination with ASP intervention AXDX significantly reduced time to optimal therapy by 13.1 hours, ASP intervention alone also improved the proportion of patients on optimal therapy within 48 hours. DISCLOSURES: K. Ehren, Accelerate Diagnostics Inc.: Research Contractor, Research support. A. Meißner, Accelerate Diagnostics Inc.: Research Contractor, Research support. J. Ertel, Accelerate Diagnostics Inc.: Research Contractor, Research grant. H. Seifert, Accelerate Diagnostics Inc.: Research Contractor, Research grant.