1494. Does Rapid Microorganism Identification Improve Time to Receipt of Effective Antimicrobial Therapy
Session: Poster Abstract Session: Antimicrobial Stewardship: Role of Diagnostics
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • malditof poster.png (461.9 kB)
  • Background: Timely receipt of effective antimicrobial therapy for the treatment of infectious diseases results in improved patient survival and shorter hospital length of stay. The introduction of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) into the hospital microbiology laboratory has resulted in the rapid microorganism identification. For the benefits of such technology to be recognized, culture results must be acted on when available. The incorporation of MS technology brings with it the promise of rapid pathogen identification; its clinical impact however, is less well understood. Does rapid organism identification shorten time to receipt of effective antimicrobial therapy for patients with bloodstream infections?

    Methods: Case control study of bacteremic patients whereby the infecting organism was identified by MS compared with historical controls whose organisms were identified via VITEK-2. Patients were matched based on pathogen, age, sex, and PITT bacteremia score. Time from index culture positivity to receipt of effective antimicrobials was assessed for each patient. 

    Results: Sixty-nine patients in the MS group were matched with 69 historical controls. Time to organism identification was 18.7 hours (h) in the MS group compared with 26.7h in the control group (p<0.0001). Time to receipt of effective antimicrobial therapy was 22.1h in the MS group and 25.3h in the control group (p=0.676). Thirty patients had gram-positive bacteremia, time to organism identification was 16.7h in the MS group and 26.7h in the control group (p<0.0001); time to receipt of effective antimicrobial therapy was 27.4h in the MS group and 22.8h in the control group (p=0.748). Thirty-eight patients had gram-negative bacteremia, time to organism identification was 20.4h in the MS group and 26.4h in the control group (p<0.0001); time to receipt of effective antimicrobial therapy was 20.6h in the MS group and 33h in the control group (p=0.138).

    Conclusion: Integration of rapid organism identification into hospital laboratories results in decreased time to organism identification but did not result in more rapid initiation of effective antimicrobial therapy.

    Lynn Nadeau, PharmD and Margaret Tarnawski, PharmD, Pharmacy, Windsor Regional Hospital, Windsor, ON, Canada

    Disclosures:

    L. Nadeau, None

    M. Tarnawski, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.