PSHP 2026 Residency Conference

Objective: The purpose of this study was to evaluate the impact of a pharmacist-driven antimicrobial stewardship (ASP) initiative using rapid diagnostic testing (RDT) on de-escalation of antipseudomonal antibiotic therapy for Enterobacterales bloodstream infections (BSIs).  
Methods: This was a multi-center, retrospective, comparative cohort study was approved by the institutional review board review (IRB) and included a sample of adult patients with Enterobacterales bacteremia who received empiric antipseudomonal therapy. Treatment was compared pre- and post- implementation of RDT. The primary outcome was time (hours) to de-escalation of antipseudomonal coverage. Secondary outcomes included days of antipseudomonal antibiotic therapy, 30-day mortality, and incidence of Clostridioides difficile infection (CDI). A subgroup analysis was also conducted to evaluate the use of anti-methicillin resistant Staphylococcus aureus (MRSA) therapy. Antimicrobial stewardship activities were also evaluated in the post-implementation group. 
Results: This study included 44 patients in the pre-implementation group and 60 patients in the post-implementation group. Baseline characteristics were comparable between both groups. The median time (hours) to de-escalation of antipseudomonal coverage for Enterobacterales bacteremia was found to be significantly lower in the post-implementation group (9.3 vs 50.5, p < 0.001). Median days of therapy was also found to be lower in the post-implementation group (2 vs 4 days, p < 0.001). The 30-day mortality rate, CDI events, and days of anti-MRSA therapy were not statistically different between groups. 
Conclusion: This study demonstrated that a pharmacist-driven antimicrobial stewardship initiative was successful in reducing time to targeted therapy in hospitalized patients receiving treatment for Enterobacterales bacteremia.