Clinical impact of the BCID2 and rapid AST VITEK® REVEALTM on antibiotic optimisation in critically ill patients with Gram-negative bloodstream infections: a quasi-experimental pre/post interventional study.

Background: Rapid diagnostic tools (RDT), together with rapid antimicrobial susceptibility testing (rAST), have emerged as means to shorten the time to pathogen identification and AST for bloodstream infections (BSI). Whether these techniques significantly impact antimicrobial therapy in critically ill patients with BSI remains to be determined.

Methods: A single-center quasi-experimental study comparing antibiotic optimisation before and after the implementation of innovative RDT, BIOFIRE® Blood Culture Identification 2 (BCID2) Panel and VITEK® REVEALTM (bioMérieux), was conducted. All adult patients admitted to the intensive care unit (ICU) with a first episode of Gram-Negative Bacilli BSI were included in the study. The primary outcome was the proportion of patients receiving optimized antibiotic therapy within 24 h of blood culture incubation.

Results: A total of 100 patients, 50 in each study period, were included. The proportion of patients receiving optimized antibiotic therapy within 24 h of blood culture incubation was not significantly different in the post-interventional (28%) compared with the pre-interventional group (20%) (P = 0.3). When considering antibiotic therapy optimisation within 24 h of positive blood culture, the proportion of patients with optimized antibiotic therapy was significantly higher in the post-intervention group (46% versus 26%, P = 0.037). The time to optimisation in the RDT group was shorter than in the conventional group, 27 h versus 46 h, respectively (P < 0.001).

Conclusions: The real-world implementation of RDT significantly shortened time to results but did not improve antibiotic therapy optimisation within 24 h of blood culture incubation. An antimicrobial stewardship programme could help enhance the clinical impact of RDT.