(585) Impact of Pharmacist-Led Antimicrobial Stewardship Rounds in a Critical Care Unit

Introduction: Patients admitted to intensive care units are at high risk of developing multi-drug resistant (MDR) infections. Antimicrobial stewardship programs (ASPs) utilize different tactics to promote the appropriate use of antimicrobial agents with the goal of decreasing antimicrobial exposure, antimicrobial resistance, and healthcare associated costs without increasing mortality. We evaluated the impact of twice-weekly pharmacist-led antimicrobial stewardship rounds (ASRs) on antimicrobial exposure in a critical care unit.

Methods: This was a retrospective cohort study of patients admitted to University of California San Diego Hillcrest Critical Care Unit comparing antimicrobial use before and after implementation ASRs. Antimicrobial use was evaluated over a fifteen-month interval from May 2018 until August 2019 in the pre-implementation cohort and from May 2022 until August 2023 in the post-implementation cohort. Linear regression was performed to identify if the intervention was associated with a change in antimicrobial usage.

Results: Our analysis included 114 medical ICU patients; 83 patients in the pre-implementation cohort and 31 patients in the post-implementation cohort. The mean age in the study population was 58.3 years (standard deviation [SD], 17.5 years) and 56.1% were male. The average ICU length of stay was 8.9 days (SD, 6.4) and comparable between cohorts. Linear regression suggests a decrease in antimicrobial usage in the CCU by 5.4 days (95% CI, -8.4 to – 2.3) after implementation of pharmacist-led ASRs. Broad spectrum antibiotic exposure (p = 0.001) and MRSA active agent exposure (p = 0.006) were significantly reduced in the post-implementation cohort. There was no difference in narrow spectrum antibiotic or pseudomonas coverage between the cohorts. Post-implementation was associated with a decrease in vancomycin exposure (p = 0.020) and vancomycin drug levels (p = 0.021). Overall, 30-day mortality (27.2%) did not differ significantly between the cohorts.

Conclusions: This study found that twice-weekly ASRs were associated with decreased antimicrobial exposure without increasing mortality. Future studies are needed to assess the effect on the rate of multi-drug resistant organisms, rates of clostridium difficile, and the impact on healthcare associated costs.