Impact of same-day antibiotic susceptibility testing on time to appropriate antibiotic treatment of patients with bacteraemia: a randomised controlled trial

Abstract

Inadequate therapy in bloodstream infections is suggested to be associated with higher mortality. We evaluated the reduction in inappropriate antibiotic therapy using rapid identification and antibiotic susceptibility testing (FAST) compared to standard of care (SOC) testing in patients with bloodstream infections. The FAST method used polymerase chain reaction (PCR) for identification and to detect growth in the presence or absence of antibiotics after only 6 h. For SOC testing, the BD Phoenix system was used. Patients with blood cultures growing Staphylococcus, Streptococcus or Enterococcus species or Gram-negative rods were randomised for FAST or SOC tests. A total of 129 patients were randomised for FAST and 121 patients for the SOC group. At the time SOC results became available, 78 patients in the FAST group could have been switched to more appropriate therapy. Although FAST results were highly accurate (agreement with SOC was 94%), they were only implemented in a minority (16) of patients. However, significantly fewer patients in the FAST group used inappropriate therapy at the time of SOC results (p = 0.025). The time to results in the FAST group was reduced by 15.6 h (p < 0.001). In the patients switched after FAST, this was done after a mean of 42.3 h compared to 61.4 h in those switched after SOC tests (p < 0.001). In bacteraemic patients, FAST resulted in significantly more patients using appropriate antibiotic therapy at the time SOC results were available and 15.6 h earlier than SOC tests. However, the implementation of FAST results was not optimal and no benefit on clinical outcome was shown.

The Cost-Effectiveness of Rapid Diagnostic Testing for the Diagnosis of Bloodstream Infections with or without Antimicrobial Stewardship

“…All studies that provided available mortality data (9, 17-25, 34, 36-45) were included in our analysis, while studies conducted outside the United States (46)(47)(48)(49)(50)(51) or studies that included pediatric patients (35) were excluded. Overall mortality estimates, which were then used to yield probabilities of survival, were obtained by pooling the mortality rates of the included studies with the use of a random-effects meta-analysis (Der Simonian and Laird) (52,53).…”

Prospective intervention study with a microarray-based, multiplexed, automated molecular diagnosis instrument (Verigene system) for the rapid diagnosis of bloodstream infections, and its impact on the clinical outcomes

“…The most important benefit of the rapid diagnostic methods, including the Verigene system examinations, is their rapidity in providing results. For example, there were limited clinical benefits recognized in a recent clinical trial that utilized a multiplexed molecular method for bacteremia, which required 51 h to report the results of the molecular method after the blood culture obtained [34]. In addition, the results might not be useful if the physician does not understand the results or change antimicrobial agents as appropriate.…”

Utility of direct susceptibility testing on blood cultures: is it still worthwhile?

“…In addition, the clinical utility of such rapid results needs to be evaluated. A recent study assessed the clinical outcome of rapid antimicrobial susceptibility testing by using PCR to detect micro-organisms grown in the presence or absence of antibiotics after only 6 h. This randomized controlled trial was not able to show a clinical benefit compared to standard susceptibility testing, which the authors attributed to a suboptimal implementation of the rapid results (Beuving et al, 2015).…”