Effect of Direct-from-blood Bacterial Testing on Antibiotic Administration and Clinical Outcomes

Study Summary

Bacterial blood stream infections are common and life-threatening. Bloodstream infections have historically been identified using blood cultures, which often take 24-72 hours to result and are imperfectly sensitive. Early administration of antimicrobial therapy is a fundamental component of the management of adults presenting to the hospital with a suspected bloodstream infection and/or sepsis. But because blood cultures frequently take 24-72 hours to result, patients are typically treated with empiric, broad spectrum antibiotics. In a meta-analysis of sepsis studies, empirical antibiotic therapy was inappropriate for the organism that ultimately grew in culture in almost half of patients. Thus, patients are commonly exposed to unnecessary antibiotics without evidence of infection or with evidence of infection requiring narrow antibiotic selection. For example, current guidelines recommend the use of empiric intravenous vancomycin as coverage for a bloodstream infection caused by the bacterial pathogen methicillin-resistant S. aureus (MRSA). Vancomycin requires careful monitoring due to its narrow therapeutic range and high risk of toxicity. Administration of vancomycin to patients who do not have MRSA can lead to avoidable adverse drug events and costs, as well as drive antimicrobial resistance. There has been increasing interest in using rapid diagnostic tests that identify bacteria directly from whole blood samples without relying on growth in culture, referred to as "direct-from-blood" tests, to guide early therapeutic management of patients with suspected bloodstream infections in addition to standard blood cultures. One such FDA-approved, direct-from-blood test is the T2Bacteria® Panel. This panel's performance as a direct-from blood test for bacterial pathogens has been described in previous studies. A recent meta-analysis of largely observational studies reported a faster transition to targeted microbial therapy and de-escalation of empirical microbial the

Primary Outcome

The time between randomization and the start time for the last dose of intravenous vancomycin received by the patient within 14 days of randomization.

Interventions

• OTHER Usual Care
• OTHER T2Bacteria® Panel (direct-from-blood testing)