Antimicrobial Stewardship Pharmacist Interventions for Coagulase-Negative Staphylococci Positive Blood Cultures Using Rapid Polymerase Chain Reaction

Abstract

No studies exist regarding the value of pharmacist interventions using rapid identification of coagulase-negative staphylococci (CoNS) by rapid polymerase chain reaction (rPCR) from blood cultures. To evaluate the impact of interventions by infectious diseases pharmacists (ID PharmDs) on blood cultures positive for CoNS using rPCR and assess the duration of antistaphylococcal antibiotic therapy, hospital length of stay (LOS), and related costs. A quasi-experimental, pre- and postintervention study of patients with positive blood cultures for CoNS, identified using rPCR, was conducted. Patients were included if there was a blood culture for CoNS from January 1, 2011, to March 31, 2011 (preintervention), or October 1, 2011, to January 18, 2012 (postintervention). Exclusion criteria included age younger than 18 years or 89 years or older, neutropenia, incomplete records, and duplicate or mixed blood cultures. The setting was a 1200-bed academic medical center. The ID PharmD intervened on blood cultures identified in the postintervention group as CoNS after notification from the microbiology laboratory. The pre- and postintervention groups were compared to analyze the effect of the intervention. The primary outcome was time to discontinuation of antistaphylococcal antibiotics by the pharmacist intervention in patients with a positive blood culture for CoNS that was determined to be a contaminant. We analyzed 53 patients (31 preintervention, 22 postintervention) with CoNS blood culture contaminants. In the postintervention group, antistaphylococcal antibiotics were discontinued 32.0 hours sooner from time of rPCR result (median 57.7 vs 25.7 hours; p = 0.005), total antibiotic exposure decreased 43.5 hours (97.6 vs 54.1 hours; p = 0.011), infection-related LOS decreased 4.5 days (10 vs 5.5 days; p = 0.018), and infection-related costs decreased $8338 ($28,973 vs $20,635; p = 0.144). The pharmacist initiated vancomycin in 7 (21.9%) patients with CoNS bloodstream infections. Timely interventions by ID PharmDs using rPCR are required to impact the outcomes of patients with positive blood cultures for CoNS.