Clinical impact of pharmacist-directed antimicrobial stewardship guidance following blood culture rapid diagnostic testing

Abstract

Background: Rapid diagnostic testing (RDT) has been shown to be associated with improved clinical outcomes. Aim: To evaluate the clinical outcomes of using RDT paired with well-defined pharmacist-directed antimicrobial stewardship programme (ASP) guidance to achieve targeted treatment in patients with bacteraemia. Methods: In this quasi-study, a retrospective (pre-intervention) phase was compared with a prospective (post-intervention) phase. Adult patients with positive blood cultures identified using the BacT/ALERT system were included. Bacterial identification and susceptibility were provided by VITEK 2. During the post-intervention phase, Verigene ASP guidance was developed to optimize antibiotic selection. Pharmacists received the results from the microbiology laboratory, evaluated the appropriateness of current therapy (if any), and communicated the recommended antimicrobial therapy to the treating physician accordingly. Findings: The cohort consisted of 164 patients in the pre-intervention group and 148 patients in the post-intervention group. When comparing the post-intervention period with the pre-intervention period, the median time to culture identification was 22 vs 96 h (P<0.0001), median time to targeted antibiotics was 2 vs 22 h (P<0.0001), median time for antibiotic de-escalation was 12.2 vs 27 h (P<0.0001), and median time to escalation was 1.3 vs 24 h (P<0.003), respectively. In-hospital mortality and 30-day re-admission were significantly lower in the post-intervention group (P<0.003 and 0.034, respectively). Length of hospital stay was significantly shorter in the post-intervention group (6.5 vs 8 days; P=0.03). Conclusion: Rapid identification of bacteraemia combined with a pharmacist's recommendation as an ASP initiative significantly improved time to optimal therapy, and may have decreased the risk of mortality and re-admission.