Abstract
Hematologists that are expert in benign hematology are needed to promote safe and cost-effective diagnosis of bleeding and thrombotic disorders in the hospital setting. The Joint Commission has identified anticoagulation as an area that has a high frequency of adverse drug outcomes and needs close supervision. The purpose of this study is to demonstrate the clinical utility of benign hematology expertise to guide use of direct thrombin inhibitors (DTIs) in the setting of heparin-induced thrombocytopenia. Heparin-induced thrombocytopenia represents a serious complication of heparin therapy and requires accurate diagnostic testing and safe and effective anticoagulation to prevent adverse outcomes. In recent years, serologic tests for the presence of heparin–platelet factor 4 antibodies has led to widespread testing and increased use of DTIs to manage thrombocytopenic patients. Patients that have a positive ELISA assay are tested by the serotonin release assay to confirm the presence of the antibody that can trigger thrombosis. The antibody can trigger platelet activation, arterial thrombosis and/or venous thrombosis. The risk of a thrombotic event is high and anticoagulation is recommended to reduce thrombosis that can lead to amputation, stroke, or loss of life. Treatment is recommended with a DTI followed by warfarin therapy. The American Society of Hematology and several expert panels have published guidelines regarding management of heparin-induced thrombocytopenia. Despite these guidelines, medical centers are challenged by regulating the diagnosis and management of this clinical problem. The Medical University of South Carolina Hospital, a 750 bed academic medical center, established an Anticoagulation and Bleeding Management Service led by hematologists and a multidisciplinary team to evaluate the use of diagnostic testing and use of DTIs. In phase one, a review of the testing in the intensive care units at our medical center was retrospectively analyzed. Results demonstrated a high frequency of serologic testing in cases that had low to intermediate 4T score results. In contrast, a very low percentage of ELISA-positive cases were confirmed to be serotonin release assay-positive. Often times DTIs were administered for several days until the SRA assay results were available. In collaboration with nursing, pharmacy, pathology and hematology, a specific set of guidelines were implemented. Prior to submitting an ELISA measurement clinicians were required to perform a 4T score. All positive ELISA assays were reported to the Anticoagulation and Bleeding Management Consult Service and specific treatment guidelines were provided in accordance with published ASH guidelines. We collected and reviewed baseline data regarding the frequency of testing and use of DTIs prior to implementing the protocol. We found that an average of 5.5 cases per month were given DTIs prior to implementation of the protocol. The average number of patients treated with DTI after the implementation of the protocol averaged 1.2 per month . This represented a 78% drop in DTI use. Over the same time period we saw ELISA testing and SRA testing both decline, with ELISA testing reduced by 20% and Serotonin Release Assay testing reduced by 70%. In conclusion, the implantation of a centralized hospital-wide protocol that coordinates testing and treatment of patients suspected of having heparin-induced thrombocytopenia has led to a substantial reduction in use of DTIs and improved management of patients suspect of having this clinical disorder. An Anticoagulation and Bleeding Management Service led by expert benign hematologists can play a major role in developing safe and cost-effective approaches for the diagnosis and treatment of complicated bleeding and thrombotic disorders.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
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