Résumé
Rapid diagnostic tools together with rapid antimicrobial susceptibility testing (rAST) have emerged as a means to shorten the time to pathogen identification and AST for bloodstream infections (BSI). We assessed the clinical impact of the new diagnostic solutions BacT/Alert® VIRTUO®, BioFire® Blood Culture Identification 2-BCID2, and VITEK® REVEALTM (bioMérieux) on the antibiotic therapy optimization of Gram-negative bacilli (GNB) BSI in intensive care unit (ICU) patients. Methods: a single-center quasi-experimental study comparing antibiotic optimization before and after the implementation of the new diagnostic solutions. Adult patients with a first episode of GNB BSI admitted to the ICU were included in the study. The primary outcome was antibiotic therapy optimization (according to the modified Weiss et al. classification) within 24 hours of blood culture handling in the laboratory. Results: a total of 100 patients, 50 in each group, were included. The proportion of patients receiving optimized antibiotic therapy at 24 hours was not significantly different in the post-interventional group compared to the pre-interventional group, 28% vs. 20%, respectively (p=0.3). The length of stay (LOS) in the ICU was shorter by 8 days in the post-interventional group (p=0.049). There were no significant differences in the overall time to optimization, prevalence of multidrug-resistant (MDR) bacteria, or 28-day mortality. The time to optimization in VITEK® REVEALTM rAST-based optimized patients was shorter than in conventional AST-based optimized patients, 27 hours vs. 46 hours, respectively (p<0.001). Conclusions: the real-world implementation of RDT combined with VITEK® REVEALTM rAST (bioMérieux) did not improve antibiotic therapy optimization within 24 hours of blood culture handling. Physician reluctance to de-escalate antibiotic therapy based on rAST alone limits its clinical impact. A rigorous antimicrobial stewardship program integrating the psychosocial factors of antimicrobial prescribing could help enhance the clinical impact of rAST.