Impact of Rapid Susceptibility Testing System on the Management of Gram-Negative Bacteremia in a Network of Community Hospitals

Abstract

Background: Rapid initiation of optimal antimicrobial therapy is crucial for the management of Gram-negative (GN) bacteremia. We aimed to evaluate the impact of Accelerate PhenoTM (AxDx) system on change in therapy and length of stay among patients with GN bacteremia.

Methods: We conducted a retrospective cohort study of adult patients hospitalized who had at least 1 blood culture with presence of Enterobacterales. We compared clinical outcomes among patients who had their blood cultures processed through standard methods alone vs AxDx.

Results: We identified 255 bacteremia episodes among 243 unique patients. In the AxDx group, 31.1% of patients had deescalation of antibiotics within 48 h from blood culture collection compared to 20.0% of patients in the control group (P = 0.09). We found no impact of AxDx on the odds of deescalation at 48 h from blood culture collection [odds ratio (OR) 1.80 (95% CI 0.91-3.56), P = 0.09] or Gram stain report [OR 1.61 (95% CI 0.86-3.01), P = 0.14]. Escalation in therapy at 48 h from blood culture collection occurred in 16.8% and 16.9% of patients in the AxDx and control groups, respectively (P = 0.99). There was no impact on the odds of escalation at 48 h from blood culture collection [OR 0.99 (95% CI 0.47-2.11), P = 0.99] or Gram stain report [OR 1.26 (95% CI 0.57-2.80), P = 0.57]. No differences were seen in length of stay and mortality between the 2 groups.

Conclusions: The impact of rapid identification and susceptibility technologies may differ according to the setting in which they are implemented.

Keywords: Gram-negative bacteremia; antimicrobial susceptibility testing; rapid diagnostics.