Implementation of a Pharmacist-Directed Antimicrobial Stewardship Protocol Utilizing Rapid Diagnostic Testing

Background: Rapid identification of gram-positive bacteria and resistance determinants from blood cultures can reduce the time to optimal antibiotic therapy. Objective: This study evaluates the use of technology to rapidly identify gram-positive bacteria in combination with a pharmacist-directed antimicrobial stewardship protocol in a tertiary-care facility. Methods: Rapid diagnostic testing was performed on gram-positive blood cultures. Pharmacists were instructed to notify prescribers of results and recommend appropriate antimicrobial therapy based on targeted treatment chart. The primary outcomes were mean time to optimal antibiotic therapy, mean time antibiotics were avoided before traditional culture results, and percent of patients with time to optimal antibiotic therapy reached in less than or equal to 2 hours. Results: Inclusion criteria were met for 297 patients. Mean time to identify bacteria was 26.8 hours with nucleic acid assay versus 75.3 hours with traditional culture (difference = 48.5 hours, p < .0001). The rapid identification of gram-positive bacteria combined with accepted pharmacist intervention improved time to optimal antibiotic therapy (8.4 vs 15.4 hours, p = .0095). When contaminants were identified, antibiotics were avoided for 39.5 hours before traditional culture with pharmacist intervention versus 37.2 hours (p > .05). Antibiotic change occurred in less than or equal to 2 hours in more patients in the pharmacist intervention group (28% vs 10.5%, p = .0002). Conclusions: Rapid identification combined with pharmacist intervention significantly improved time to optimal antibiotic therapy and significantly increased the number of patients receiving optimal antibiotic therapy in less than or equal to 2 hours over rapid identification alone. A pharmacist-directed protocol combined with rapid identification enhanced antimicrobial stewardship.