The Positive Blood Culture as a Stewardship Opportunity: Time to Appropriate and "Best Therapy" is a Useful Quality Gauge Across an Acute Care Hospital
Background: To assess the appropriateness of antimicrobial therapy of patients with positive blood cultures in a tertiary care setting, the timeliness of antibiotic administration, and streamlining of therapy in response to microbiologic data generated using MALDI-tof. . Methods: Over a 4-week period, all inpatients (University of Alberta Hospital) with new positive blood cultures were enrolled prospectively. Data collected included Microbiology, patient demographics, comorbidities and antimicrobial therapy. The final antimicrobial regimen was categorized as the “Best Therapy” or not, based on susceptibility testing, clinical factors including coinfections, allergies and cost. The timeliness of antibiotic therapy and streamlining was assessed based on the time of the positive culture call, the times antibiotics were ordered and administered, and the time culture, and updated susceptibility reports became available.
Results: 48 positive blood cultures were included (19%- E. coli, 12%- Staph. aureus, 10% - Enterococcus and 15.5% -Streptococcus). The most commonly suspected sources were urosepsis (24%) and pneumonia (12%). Over 80% of empiric antimicrobial orders were concordant with Microbiologists recommendations. Ceftriaxone, piperacilin-tazobactam, vancomycin and azithromycin were the most common empiric antibiotics (36.2%, 25.9%, 25.9% and 12.1% respectively). Based on final culture and sensitivities, 34.5% of empiric therapy was inadequate; however, 89.7% of all positive blood cultures patients received eventual “Best Therapy”. It took a median of 2.78 hours and 6.7 hours for antibiotic initiation and change after the call from microbiology and after susceptibilities were posted respectively, significant variability in the timing of antibiotic changes (0-46 hrs) and administration (0-19.75 hrs) was noted . Conclusion: Microbiologists recommendations and initial empiric therapy are >80% concordant. The majority of patients were eventually treated with best therapy; however, there are opportunities to streamline therapy earlier in the clinical course. Finally, the time to initiate and change antibiotics varies substantially, and more data involving the processes on each unit is required in order to make improvements.
M. Guirguis, None