#23 Clinical Outcomes with Rapid Gram-Positive Blood Culture Identification in an Academic Pediatric Hospital
Authors: Robertson Melena 
Published: June 2022

Abstract

Background
BACKGROUND Delays in initiating appropriate antibiotics increases mortality, length of stay, and overall admissions costs in patients with bloodstream infections. Adult studies using rapid diagnostic tests such as the GenMark’s e-Plex Blood Culture Identification (BCID) Panels coupled with Antimicrobial Stewardship Program (ASP) interventions have led to reductions in each of these metrics. Similar data assessing use in the pediatric population are generally lacking. The primary aim of this study was to assess the impact of the GenMark Blood Culture Identification Gram Positive panel (BCID-GP panel) on the time to optimal antimicrobial therapy (OAT) in pediatric patients with positive blood cultures growing gram-positive bacteria (GPB).

Method
METHOD A 2-year Quality Improvement study of admitted pediatric patients was carried out at UPMC Children’s Hospital of Pittsburgh (CHP) between June 25, 2019 and June 26, 2021. Pre-intervention data (6/25/19 – 6/25/20) was collected retrospectively from the CHP Electronic Medical Record (EMR). During the post-intervention time-period (6/26/20 - 6/26/21), BCID-GP panel was run daily from 6AM to 10 PM on blood cultures with Gram stains revealing GPB. Results were provided to the ASP who generated recommendations and communicated them to the patient’s primary team after reviewing the EMR using a pre-determined algorithm. Statistical analyses were performed using Wilcoxon rank sum test and Chi-squared tests.

Results
RESULTS 317 and 265 blood cultures with GPB were evaluated in the pre- and post-intervention groups, with median ages of 2.26 and 3.2 years in the 2 groups, respectively. Overall panel accuracy was 97% with gene accuracy of 100%. Percent compliance with ASP recommendations within 12 hours was 89%. The median time to OAT was 48 (range of 0-175), and 33.1 hours (range 0-165) in the pre- and post-intervention groups, respectively (p &lt;0.001). The median time to OAT for patients with MSSA decreased from 65 to 30.5 hours (p &lt;0.001), and 37 to 20 hours (p 0.048) for those with MRSA. Antibacterial therapy was avoided in 42.2% of patients in the post-intervention group when results were interpreted as contaminants, compared with 23.4% in the pre-intervention group with this assessment (p = 0.008). Length of stay and 30-day mortality was similar between groups, 6.1 days vs 6.9 days (p = 0.23) and 3.5% vs 3.4%, (p = 1.00) respectively.

Conclusion
CONCLUSION Use of BCID-GP panel significantly decreased the time to OAT and avoided initiation of antibiotics in incidences of contamination in our study population. This was also true for positive blood cultures due to MSSA and MRSA. However, significant differences in the length of stay or 30-day mortality were not identified between groups. We did find the overall accuracy, defined as the percentage of BCID panels detected targets confirmed by conventional laboratory culture and gene accuracy, defined as the percent of BCID panels with results detected confirmed by conventional laboratory susceptibility methods, of the panel mirrored with previously published data. We also found ASP recommendations based on the BCID-GP were followed 89% of the time within 12 hours of them being made.