C1. Clinical trials (abstracts submitted to C1 should choose a secondary category that describes the subject matter of the trial)
Oral Abstract Submission
Matthew P. Cheng, MD
Fellow
Brigham and Women's Hospital
Boston, Massachusetts
Disclosure: Nothing to disclose
Robert Stenstrom, M.D.
Assistant Professor
Department of Emergency Medicine, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Katryn Paquette, M.D.
Assistant Professor
Department of Pediatrics, McGill University Health Center, Montreal, Canada
Montreal, Quebec, Canada
Disclosure: Nothing to disclose
Sarah Stabler, Pharm D
Pharmacist
Department of Critical Care Medicine and Department of Pharmacy, Surrey Memorial Hospital, University of British Columbia, Surrey, Canada
Surrey, BC, Canada
Disclosure: Nothing to disclose
Murtaza Akhter, M.D.
Staff
Department of Emergency Medicine, University of Arizona College of Medicine, Phoenix, United States
Pheonix, AZ
Disclosure: Nothing to disclose
Adam Davidson, M.D.
Assistant Professor
Department of Emergency Medicine, Lion’s Gate Hospital, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Marko Gavric, BSc
Student
School of Kinesiology, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Alexander Lawandi, M.D.
Fellow
Division of Infectious Diseases, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, Quebec, Canada
Disclosure: Nothing to disclose
Rehman Jinah, BSc
Student
Faculty of Medicine, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Zahid Saheed, M.D.
Resident
Department of Emergency Medicine, University of Arizona College of Medicine, Phoenix, United States
Pheonix, AZ
Disclosure: Nothing to disclose
Koray Demir, M.D.
Resident
Division of Internal Medicine, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, QC, Canada
Disclosure: Nothing to disclose
Kelly Huang, BSc
Student
Faculty of Medicine, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Amirali Mahpour, M.D.
Resident
Department of Medicine, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia
Halifax, NS, Canada
Disclosure: Nothing to disclose
Chris Shamatutu, BSc
Student
School of Kinesiology, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Chelsea Caya, MSc
Research Assistant
Division of Infectious Diseases, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, QC, Canada
Disclosure: Nothing to disclose
Jean-Marc Troquet, M.D.
Assistant Professor
Department of Emergency Medicine, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, QC, Canada
Disclosure: Nothing to disclose
Greg Clark, M.D.
Assistant Professor
Department of Emergency Medicine, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, QC, Canada
Disclosure: Nothing to disclose
Cedric Yansouni, M.D.
Assistant Professor
Division of Infectious Diseases, McGill University Health Centre, McGill University, Montreal, Canada
Montreal, QC, Canada
Disclosure: Nothing to disclose
David Sweet, M.D.
Assistant Professor
Division of Critical Care Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, Canada
Vancouver, BC, Canada
Disclosure: Nothing to disclose
Background : Current guidelines recommend obtaining blood cultures prior to antimicrobial therapy in patients with sepsis. Administering antimicrobials immediately without waiting for blood cultures could potentially decrease time to treatment and improve outcomes, but it is unclear the degree to which this strategy impacts diagnostic yield.
Methods : We performed a patient-level, single-arm, diagnostic trial. Seven urban emergency departments affiliated with academic medical centers across Canada and the United States participated in the study. Adults ≥ 18 years of age presenting to the emergency department with evidence of severe manifestations of sepsis, including a systolic blood pressure < 90 mmHg and/or a serum lactate ≥ 4 mmol/L were included. Study participants had 2 sets of blood cultures drawn prior to and immediately following antimicrobial administration. The primary outcome was the difference in blood culture pathogen recovery rates before and after administration of antimicrobial therapy.
Results : Of 3164 participants screened, 325 were included in the study (mean age, 65.6 years; 63.0% men) and had repeat blood cultures drawn after the initiation of antimicrobial therapy (median time of 70 minutes, IQR 50 to 110 minutes). Pre-antimicrobial blood cultures were positive for one or more microbial pathogens in 102/325 (31.4%) patients. Fifty-four participants (52.9%) had matching blood culture results after initiation of antimicrobial treatment. The absolute difference in pathogen recovery rates was 14.5% ([95% CI 8.0 to 21.0%]; p<0.0001) between pre and post-antimicrobial blood cultures. Results were consistent in an analysis of the per-protocol population (absolute difference, 13.3% [95% CI 6.1 to 20.4%]; p<0.0001). Including the results of other microbiological cultures done as part of routine care, microbial pathogens were recovered in 69 of 102 (67.7%) participants (absolute difference, 10.2% [95% CI 3.4 to 16.8%]; p<0.0001).
Conclusion : Among patients with severe manifestations of sepsis, the administration of empiric antimicrobial therapy significantly reduces the yield of pathogen recovery when blood cultures are drawn shortly after treatment initiation.
