Patterns of vancomycin use in high-risk febrile neutropenia.

Abstract

e23224 Background: Febrile neutropenia (FN) is a common complication in patients with hematologic malignancy. ASCO guidelines on the management of FN endorse empiric anti-Pseudomonas coverage while reserving the use of agents targeting gram-positive organisms and methicillin-resistant Staphylococcus aureus (MRSA) for select criteria-defined patients such as those with severe mucositis, hemodynamic instability, radiographic pneumonia, or history of MRSA colonization among others. We sought to examine our institutional management of FN, hypothesizing that local use of empiric vancomycin for high-risk FN will deviate from ASCO guidelines reflected in institutional policy. Methods: Case data from 1/1/2016 – 6/1/2023 was collected retrospectively, comprising patients admitted to the general medical floor with known leukemia, lymphoma, or multiple myeloma meeting ASCO criteria for FN. Patients admitted to intensive care at time of FN or for less than 48-hours were excluded. For each patient, use of vancomycin at time of FN diagnosis (t0) and 48-hours later (t48) was evaluated for congruence with society guidelines. Results: 91 patients were reviewed with a median age of 68 years old (IQR 59-74, 15). Median length of stay (LOS) was 20 days (IQR 7-29, 22) with FN occurring on day seven of hospitalization on average. Most patients receiving vancomycin were admitted to the hematology specialty unit at time of diagnosis (63%). Acute leukemia was the most common malignancy represented (62.8%), while high grade lymphoma comprised 23.1%. 98.9% of patients were on active chemotherapy at time of FN. 81 patients (89%) received vancomycin as empiric treatment for FN with 76 (93.8%) receiving vancomycin at t0. Of this latter cohort, 29.7% of patients received vancomycin at t0 without indication. At t48, vancomycin was discontinued in 28.4% of patients, 44.4% received vancomycin with true indication, and 27.2% were continued on vancomycin without indication. The median duration of therapy for patients receiving vancomycin incongruently at t48 was 4 days. Of those meeting criteria for vancomycin use at t48, severe mucositis and soft tissue infection were each cited in 22.2% of cases, followed by pneumonia, persistent fever, and hemodynamic instability. Notably, the presence of any grade mucositis was significantly associated with the continued use of empiric vancomycin at t48 (p = .025). Admission to hematology specialty unit did not significantly affect adherence to FN management guidelines. Conclusions: These data suggest that the use of vancomycin for FN at our institution deviates from society guidelines including on specialized hematology wards. This study was underpowered to assess adverse outcomes seen with vancomycin use such as renal injury, prolonged LOS and greater cost of care. Given the high complexity of this patient population, detailed provider education is indicated to promote safe, evidence-based care and broader antimicrobial stewardship.