From Diagnosis to Treatment: Getting to Optimal Therapy More Efficiently

The development of rapid diagnostic tests is being examined for the ability cut back on the time from diagnosis to treatment by improving the efficiency of pathogen identification and the ability expedite therapy and antimicrobial de-escalation.

A retrospective, cohort study demonstrated that using a rapid molecular diagnostic tests looking at contaminated blood cultures, showed the time to optimal therapy improved significantly and the vancomycin median duration decreased.

A community hospital in St. Louis Missouri implemented the BioFire FilmArray BCID in July 2019. Investigators at the hospital studied antimicrobial use for gram-positive blood cultures before and after BCID implementation to identify areas for further antimicrobial stewardship intervention. They looked at gram-positive blood culture results between February and June 2018 and 2019 (pre-and post-BCID).

They looked at 232 patients, who had a median age was 70 years and 54.3% were male. The investigators said that coagulase-negative staphylococci was most commonly isolated (n=104, 45%) and contamination rate was 53.4%.

“Median [time to optimal therapy] TTOT improved from 53.3 vs 28 hours, p< 0.001 in pre- vs post-groups, respectively, and optimal therapy selection increased from 83% to 93%, p=0.028. Median time to organism identification was 60.2 vs 23.5 hours, p< 0.001,” the investigators wrote. “Median duration for vancomycin (35.1 vs 25.2 hours, p=0.231) and overall antimicrobial duration did not differ between groups. Among contaminated blood cultures, TTOT improved (54 vs 27.3 hours, p< 0.001) and vancomycin median duration decreased (27.5 vs 16.6 hours, p=0.253).”

The results were presented as a poster, “Opportunities for antimicrobial stewardship: Time to optimal therapy and vancomycin use in gram-positive and contaminated blood cultures before and after implementation of rapid blood culture diagnostic testing,” at IDWeek 2022, held October 19-October 23, 2022 in Washington DC.

“Rapid BCID significantly improved TTOT, resulting in improved rates of optimal therapy and an observed reduced vancomycin duration,” the investigators wrote. “High rates of contaminated blood cultures identified opportunities for coordination with antimicrobial stewardship to reduce contamination rates and improve antimicrobial use.”