The Yield, Safety, and Cost-effectiveness of Decreasing Repeat Blood Cultures Beyond 48 Hours in a Pediatric Hematology-Oncology Unit.

Clear recommendations are needed on when repeat blood cultures (BCxs) in hospitalized children with cancer should be obtained. We reviewed all BCx obtained on the Hematology-Oncology Unit at Riley Hospital for Children, regardless of reason for patient admission or neutropenia status, between January 2015 and February 2021. Patients with positive BCx within 48 hours of initial cultures, history of stem cell transplant, or admitted to the intensive care unit were excluded. Medical records of patients with new positive BCx drawn >48 hours after initial BCx were reviewed. Seven (1.2%) hospitalization episodes grew new pathogens, or commensals treated as pathogens, on cultures beyond 48 hours. All patients with new, true pathogens were hemodynamically unstable or had recurrent fever when the new positive BCx was obtained. Twenty-three (4.0%) hospitalization episodes had contaminant cultures beyond 48 hours, with 74 (5.4%) of 1362 BCx collected beyond 48 hours being contaminated, resulting in an additional cost of $210,519 from increased length of stay. In conclusion, repeat BCx beyond 48 hours in pediatric hematology-oncology patients with negative initial cultures are low yield and costly. Repeat BCx can be safely and cost-effectively ceased after 48 hours of negative cultures in hemodynamically and clinically stable patients.