Impact of Rapid Antimicrobial Susceptibility Testing in Gram-Negative Rod Bacteremia: a Quasi-experimental Study
- 24 August 2020
- journal article
- research article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 58 (9)
- https://doi.org/10.1128/jcm.00360-20
Abstract
Background: Clinical justification for rapid antimicrobial susceptibility testing (AST) in Gram-negative rod (GNR) bacteremia is compelling; however, evidence supporting its value is sparse. We investigated the impact of rapid AST on clinical and antimicrobial stewardship outcomes in real-world practice. Methods: We performed a before and after quasi-experimental study from February 2018 to July 2019 at a tertiary hospital of the 24-hour/day, 7-day/week implementation of the direct VITEK®2 AST method from positive blood culture broth for GNR bacteremia with electronic isolate-specific de-escalation comments, and daytime antibiotic stewardship program (ASP) intervention. The primary outcome was time to appropriate antibiotic escalation or de-escalation, and secondary outcomes included time to oral antibiotic step-down, hospital length-of-stay (LOS), all-cause 30-day mortality, 7-day incidence of acute kidney injury (AKI) and 30-day incidence of C. difficile infection (CDI). Results: A total of 671 GNR isolates were included from 643 adult patients. Among patients for whom antibiotic change occurred after rapid AST result, rapid AST was associated with a trend in decreased time to escalation or de-escalation (hazard ratio 1.22, 95% CI 0.99-1.51; p=0.06), with median times of 52.3 vs 42.2 hours. Secondary outcomes were similar in both groups including median time to oral antibiotic step-down, LOS, all-cause mortality, and incidence of AKI and CDI. Conclusion: Rapid AST led to improved stewardship measures but did not impact clinical patient outcomes. These results highlight that multiple variables in addition to timing of AST result contribute to clinical outcome and that further intervention may be required to clinically justify rapid AST implementation.Keywords
Funding Information
- Stanford Department of Pathology
This publication has 36 references indexed in Scilit:
- Current and Emerging Methods of Antibiotic Susceptibility TestingDiagnostics, 2019
- Advances in Rapid Molecular Blood Culture Diagnostics: Healthcare Impact, Laboratory Implications, and Multiplex TechnologiesThe Journal of Applied Laboratory Medicine, 2019
- Improvement of a rapid direct blood culture microbial identification protocol using MALDI-TOF MS and performance comparison with SepsiTyper kitJournal of Microbiological Methods, 2018
- Multicenter Evaluation of the Accelerate PhenoTest BC Kit for Rapid Identification and Phenotypic Antimicrobial Susceptibility Testing Using Morphokinetic Cellular AnalysisJournal of Clinical Microbiology, 2018
- Direct-from-Blood-Culture Disk Diffusion To Determine Antimicrobial Susceptibility of Gram-Negative Bacteria: Preliminary Report from the Clinical and Laboratory Standards Institute Methods Development and Standardization Working GroupJournal of Clinical Microbiology, 2018
- Performance of the Accelerate Pheno™ system for identification and antimicrobial susceptibility testing of a panel of multidrug-resistant Gram-negative bacilli directly from positive blood culturesJournal of Antimicrobial Chemotherapy, 2018
- Evaluation of the Accelerate Pheno System for Fast Identification and Antimicrobial Susceptibility Testing from Positive Blood Cultures in Bloodstream Infections Caused by Gram-Negative PathogensJournal of Clinical Microbiology, 2017
- Randomized Trial of Rapid Multiplex Polymerase Chain Reaction–Based Blood Culture Identification and Susceptibility TestingClinical Infectious Diseases, 2015
- Identification of Blood Culture Isolates Directly from Positive Blood Cultures by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and a Commercial Extraction System: Analysis of Performance, Cost, and Turnaround TimeJournal of Clinical Microbiology, 2012
- Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock*Critical Care Medicine, 2006