Clinical and Economic Outcomes Associated with Rapid Antimicrobial Susceptibility Reporting and Dual-Card Testing in ICU Bloodstream Infections.

Abstract

Purpose: To evaluate the clinical and economic outcomes associated with implementation of an optimized blood culture workflow in intensive care unit (ICU) patients with bloodstream infections.

Patients and methods: From March 2022 to June 2023, the laboratory implemented a multi-modal workflow optimization including satellite blood culture incubation in the emergency department, upgraded blood culture bottles, rapid MALDI-TOF MS identification, automated rapid antimicrobial susceptibility testing (AST) reporting, and dual AST cards for Gram-negative bacteria. The pre-optimization group included 107 adult ICU patients with positive blood cultures (March 2021 - February 2022). The post-optimization group included 153 patients (September 2023 - August 2024).

Results: Compared to the final AST report in the pre-optimization group, the rapid AST report in the post-optimization group was 19.6 hours faster (P < 0.001). Total antibiotic use duration was 1.5 days shorter (P = 0.055). Use of two broad-spectrum antibiotics, meropenem (P < 0.001) and tigecycline (P = 0.045), decreased significantly. Hospital length of stay was 5 days shorter (P = 0.006). In unadjusted comparisons, antibiotic and hospitalization costs were reduced by 4871 CNY ([US$ 684], P < 0.001) and 13,336 CNY ([US$ 1873], P = 0.073), respectively.

Conclusion: This multimodal workflow optimization for ICU patients with BSIs, incorporating automated rapid AST reporting and dual-AST-card-enabled expanded antimicrobial panels, shortened laboratory turnaround time. It was associated with earlier opportunities for targeted antimicrobial therapy and suggests potential clinical-economic benefits, alongside possible mitigation of antimicrobial-resistance risk.