Researchers tested a stewardship-driven antibiotic treatment algorithm, incorporating rapid diagnostic testing into the management of gram-negative bacteremia, and found that the algorithm would have resulted in 10% more patients receiving appropriate antibiotic therapy vs. standard care, according to a recent study.
“There is a fair bit of literature surrounding the clinical benefits of rapid diagnostic testing with active stewardship intervention,” Kimberly C. Claeys, PharmD, BCPS, assistant professor of infectious diseases in the department of pharmacy practice and science at the University of Maryland School of Pharmacy, told Infectious Disease News.
“The majority of that literature focuses of gram-positive bloodstream infections. However, there is benefit in also developing interventions for the management of gram-negative bloodstream infections. There is emerging literature that demonstrates ability to improve appropriateness of therapy in gram-negative bloodstream infections, but few data exist. These rapid diagnostic tools are likely being underutilized in most facilities because of this lack of literature.”
From September 2015 through May 2016, Claeys and colleagues conducted a retrospective, single-center, observational study of adult patients with gram-negative bacteremia at an 800-bed academic tertiary care hospital. During the study period, they screened 256 cases of gram-negative bacteremia and included 188 patients in the final analysis. One hundred and forty-three patients were positive for organisms targeted by the Verigene Blood-Culture Gram-Negative (BC-GN) rapid diagnostic test (Luminex): Escherichia coli, Klebsiella pneumoniae, K. oxytoca, Pseudomonas aeruginosa, Acinetobacter species, Citrobacter species, Enterobacter species and Proteus species. The researchers found the most common source of gram-negative bacteremia was genitourinary, that E. coli was the most commonly identified organism.
Claeys and colleagues then applied an algorithm developed for use with the Verigene test and compared it with standard treatment.
Among 144 patients with Verigene BC-GN target organisms, there was a “moderate” level of agreement between the reviewers regarding appropriateness of standard care antibiotics and a “strong” level of agreement for algorithm recommendations, Claeys and colleagues reported. Overall, they determined the algorithm would have resulted in 88.4% of cases receiving appropriate antimicrobial therapy compared with 78.1% with standard care antimicrobials.
“The algorithm was developed by an ID pharmacist and ID physician at our institute and takes into consideration location susceptibility patterns and available literature for best practices for treating multidrug-resistant gram-negatives,” Claeys said. “It’s important that each institution should develop and validate their own algorithm for use since resistance patterns differ.”
According to Claeys and colleagues, the results “demonstrated the ability to derive a treatment algorithm using institution-specific antibiogram data, evidence-based medicine, and Verigene BC-GN results, with the potential to increase the proportion of patients receiving timely appropriate therapy compared to standard care.”
“By going through the process of validating our proposed algorithm and getting feedback from our ID physicians and antimicrobial subcommittee, we were able to gain support and institutional buy-in for the use of the algorithm,” Claeys said. “The algorithm combined with active stewardship surveillance of blood cultures allows us to assist in either timely appropriate escalation of antibiotic therapy when resistance is detected or allows us to de-escalate therapy faster when resistance is not detected.” – by Caitlyn Stulpin
Disclosures: The authors report no relevant financial disclosures.