Safety of discharge for children with cancer and febrile neutropenia off antibiotics using absolute neutrophil count threshold values as a surrogate marker for adequate bone marrow recovery

Background: Febrile neutropenia (F&N) is common among pediatric oncology patients. However, there is a lack of clarity regarding parameters whereby such patients have demonstrated adequate bone marrow recovery for hospital discharge and empiric antibiotic discontinuation. Procedure: A retrospective review was performed for 350 episodes of F&N occurring at a single institution between 2007 and 2012 in pediatric oncology patients who were afebrile for 24 hr and had no bacterial source identified. Seven-day postdischarge outcomes were assessed and compared based on absolute neutrophil count (ANC) at discharge in order to identify an optimal threshold. Results: Overall, 7-day readmission rates were low (17/350, 4.6%), with patients discharged with post-nadir ANC of 100–199/μl (2/51, 3.9%), 200–499/μl (5/125, 4.0%), and ≥500/μl (8/160, 5.0%), all having similar rates. Patients with a discharge ANC < 100/μl (2/14, 14.3%) had a higher readmission rate. A new bloodstream infection was identified upon readmission in one patient in each discharge ANC range except for ANC of 100–199/μl, in which none occurred. In a subset of 217 episodes where the ANC fell below 200/μl during the admission and subsequently rose above 100/μl, 94 episodes resulted in 126 additional hospital days while subjects awaited further count recovery. One death occurred in a patient whose ANC at discharge was 290/μl. This patient had received additional chemotherapy after count recovery and prior to discharge, and was readmitted with Clostridium tertium bacteremia. Conclusion: These results suggest that a post-nadir ANC > 100/μl is a safe threshold value for empiric antibiotic discontinuation and discharge home.