Journal Club

How Long Do We Have to Get It Right in Bloodstream Infection?

By Christopher J. Graber, MD, MPH, FIDSA

Prompt empiric broad-spectrum treatment for suspected bloodstream infection (BSI) has long been advocated to ensure that offending pathogens are appropriately covered. While urgency regarding timing and breadth of therapy may be appropriate for patients with severe sepsis or shock, data supporting this urgency for patients without severe sepsis and/or shock are less clear and often limited by bias. So just how long do we have to get it right?

In an article in Clinical Infectious Diseases, authors from an academic hospital in Sweden retrospectively reviewed 10,628 BSIs at their institution from 2012-2019, excluding BSI onset in the intensive care unit. They observed the relationship between 30-day mortality and the time from blood culture collection to when at least one antibiotic was given to which the offending organism was susceptible. To avoid immortal time bias, authors examined pre-specified landmarks of 1, 3, 6, 12, 24, 48, and 72 hours, excluding deceased patients at each time point. 

By 3 and 12 hours, 50.4% and 87.4% of patients had received appropriate therapy, respectively. Septic shock was present in 5.7%, and overall 30-day mortality was 11.8%. No association favoring a protective effect between appropriate therapy and 30-day mortality was seen at 1, 3, and 6 hours, but after 12 hours (adjusted odds ratio (aOR) 1.17 [95% confidence interval (CI) 1.01-1.37]) mortality risk gradually increased, reaching aOR 1.67 (95% CI 1.30-2.15) at 72 hours, a finding that held up in multiple sensitivity analyses.

The study was limited by a low proportion of BSI caused by antimicrobial-resistant pathogens (n=420), its retrospective, non-randomized nature, and uncertainty as to exactly when BSI begins, with time of blood culture collection used as a surrogate here. Nevertheless, it provides a strong argument for ensuring time for an appropriate workup for infectious source and pathogen identification, especially for patients not in septic shock and especially in the era of rapid diagnostic tests that can result in pathogen identification well within a 12-hour window.  

(Van Heuverswyn et al. Clin Infect Dis. Published online: Sept. 6, 2022)