Pharmacist‐driven methicillin‐resistantStaphylococcus aureus screening protocol and the impact on vancomycin exposure in hospitalized patients with pneumonia

Abstract

AbstractIntroductionAlthough methicillin‐resistant Staphylococcus aureus (MRSA) is a rarely identified pathogen of pneumonia, providers are often compelled to use anti‐MRSA antibiotics empirically. As a result, patients may be exposed to unnecessary anti‐MRSA antibiotic therapy. Polymerase chain reaction (PCR) nares screening for MRSA colonization has repeatedly shown a negative predictive value of >95% for MRSA pneumonia. Therefore, nares screenings have the potential to serve as a valuable tool to de‐escalate anti‐MRSA antibiotics for patients with pneumonia. Our institution implemented a protocol whereby pharmacists order a MRSA PCR screen for patients with suspected MRSA pneumonia at the time of vancomycin initiation. For negative MRSA PCR results, pharmacists contact the provider and recommend discontinuation of vancomycin.ObjectivesThe primary objective of this study was to evaluate the impact of pharmacist‐driven MRSA PCR nares screening on duration of vancomycin therapy for patients with pneumonia.MethodsThis study was a retrospective cohort study of patients with suspected MRSA pneumonia pre‐ and post‐protocol implementation. The study was conducted at a community teaching hospital September 1, 2017 through November 30, 2017 (control) and September 1, 2018 through November 30, 2018 (intervention). Patients were excluded for the following: concomitant non‐pulmonary MRSA infection, septic shock requiring vasopressors, confirmed MRSA infection within the last 30 days, cystic fibrosis, or bronchiectasis. The primary endpoint was duration of vancomycin therapy.ResultsOur institutional review board‐approved study included 196 patients (n = 81 pre‐protocol, n = 115 post‐protocol). Post implementation of the MRSA nares screen protocol, patients received a significant reduction in median hours of vancomycin (38 vs 23.5 hours, P = .002). Reduction in vancomycin exposure was not found to adversely affect clinical outcomes such as length of stay or readmission at 30 days.ConclusionsImplementation of a pharmacist‐driven MRSA nares screen significantly and safely reduces unnecessary vancomycin exposure in patients with suspected pneumonia.