(529) Pharmacy Protocol Decreases Vancomycin Use for Empiric Pneumonia

Introduction: Recommendations regarding the need for anti-methicillin-resistant Staphylococcus aureus (MRSA) therapy in pneumonia vary in guidelines. Recent primary literature supports the use of MRSA nares screening to aid in timely de-escalation of agents targeting MRSA. Additionally, a recent multicenter cohort study suggests empiric anti-MRSA therapy was not associated with reduced mortality for adults hospitalized for pneumonia. However, literature has also shown anti-MRSA therapy use has increased despite a decrease in positive MRSA cultures. Therefore, the study site implemented two pharmacy protocols to decrease unnecessary anti-MRSA therapy in pneumonia.

Methods: Two pharmacy protocols were implemented in Q3 2020. First, vancomycin was discontinued if the patient was only receiving vancomycin for pneumonia, respiratory cultures demonstrated no significant growth of MRSA (if available), and MRSA nares screen was negative. Additional evidence and local data then led to expansion of the protocol which allowed pharmacists to automatically discontinue empiric vancomycin for pneumonia unless the patient was in septic shock requiring vasopressors or respiratory failure requiring mechanical ventilation.

Results: The ICU MRSA Standardized Antimicrobial Administration Ratio (SAAR) decreased from 1.02 in 2020 to 0.55 in 2021 and 0.69 in 2022. When including all units at the study facility, the SAAR decreased from 0.99 in 2020 to 0.65 in 2021 and 0.79 in 2022. The monthly ICU vancomycin days of therapy (median) per 1000 days present decreased from 160 and 120 in 2019 and 2020, respectively to 71 and 89 in 2021 and 2022, respectively.

Conclusions: Anti-MRSA therapy stewardship led by pharmacists decreased vancomycin use in the ICU. Future goals at the study site include expanding the anti-MRSA therapy stewardship to other indications, given the high negative predictive value of the MRSA nares screening.