336: EVALUATION OF A PHARMACY-MANAGED HEPARIN-INDUCED THROMBOCYTOPENIA STANDARD OPERATING PROCEDURE

Abstract

Introduction: Heparin-induced thrombocytopenia (HIT) is associated with significant morbidity and mortality, necessitating early identification and timely diagnosis. The objective of this study was to evaluate a pharmacy-managed HIT standard operating procedure (SOP). Methods: A retrospective analysis of HIT laboratory testing at Nebraska Medicine before (April 2018 to August 2019) and after (April 2020 to August 2021) SOP implementation was performed on patients admitted to the ICU. Patients were included if an anti-PF4 antibody and/or SRA test was ordered during hospitalization with prior heparin exposure. Exclusion criteria were age < 19, no heparin product exposure prior to HIT laboratory testing, or if lab testing was ordered ≥15 days from receiving heparin. The primary outcome was appropriately documented heparin allergy field in the medical record. Secondary outcomes include false positive anti-PF4 antibody assays, time from heparin initiation to HIT laboratory testing, duration of direct thrombin inhibitor (DTI) use, hospital length of stay, and in-hospital all-cause mortality. Results: 226 patients were evaluated, 110 in the pre- and 116 in the post-cohort. Baseline characteristics demonstrated most patients were male (58.8%), white (81.4%), and were anticoagulated with an indication of VTE prophylaxis (61.1%). Acute trauma/surgical procedure was the most common reason for admission (31%). Appropriate heparin allergy documentation occurred in 95.5% of patients in the pre- and 97.4% of patients in the post- cohort (p=0.528). No difference was found in the incidence of false positive anti-PF4 antibody assays (9.1% vs 8.6%) or time from heparin initiation to HIT laboratory testing (3.2 vs 3.6 days). DTI’s were utilized for a longer duration of time in the pre- cohort compared to the post-cohort (4.9 vs 2.8 days). There was no difference in hospital length of stay (17.9 vs 17.4 days), but in-hospital all-cause mortality was observed more frequently in the post-cohort than the pre-cohort (36.2% vs 23.6%). Conclusions: The implementation of a pharmacist-driven heparin-induced thrombocytopenia standard operating procedure demonstrated a similar incidence of appropriate heparin allergy documentation in the medical record compared to a physician-driven approach.