36 Management of a positive blood culture in paediatric emergency department: A multicenter case-based survey

Abstract Background Positive blood cultures in paediatric Emergency Departments (ED) represent a diagnostic dilemma for clinicians as 50% are due to contaminants. As such, the risk of misinterpretation is costly and can lead to inappropriate antibiotic use, blood tests, and hospitalization. Despite the prevalence and ramifications of this diagnostic uncertainty, current clinical practice lack established guidelines. Objectives Our aim was to characterize the management of positive blood cultures by physicians working in paediatric EDs across Canada. In addition, we identified factors influencing how physicians distinguish true bacteremia from contaminants. Design/Methods A self-administered electronic survey was sent to all members of the Paediatric Emergency Research Canada (PERC) network in 2024 using the principles of the Dillman’s Tailored design method. The survey was constructed using standardized methodology. Potential risk factors of bacteremia were identified based on a literature review and consultation of multiple experts. The survey consisted of three clinical cases, modeled off real patients, and was pilot tested by a group of physicians. Each case highlighted a common clinical scenario in which physicians had to interpret the significance of a positive blood culture. There were follow-up questions to further assess clinical decision-making and provide demographic information. The primary outcome was the management of a positive blood culture according to the participant. Results Of the 221 PERC members invited, 153 (69%) were included in the final analysis. In brief, 65% of the participants were trained in paediatric emergency medicine and 55% had more than 15 years of experience. The management of the case scenarios was heterogeneous, for example, 49% of participants would have discharged a 9-week-old with a positive culture and otherwise normal blood results and absence of fever at follow-up, while 35% suggested hospitalization with IV antibiotics. Most participants identified young age, immunocompromised status, and shorter time to blood culture positivity as risk factors for true bacteremia, though consensus on time-to-positivity remained unclear. Only 17% of physicians reported use of a clinical guideline, largely from one site, and 98% reported that they would be willing to adopt a clinical decision rule if it had a high sensitivity. Conclusion This study highlights the considerable variation in practice across Canadian paediatric EDs and the need for standardized guidelines. Young age, immunocompromised status, and shorter time to blood culture positivity are risk factors used by ED physicians to assess the probability of true bacteremia among children with positive blood culture.