The Anti-Xa Assays: Therapeutic Monitoring of Heparin

Explore Alternatives to Traditional Monitoring

Heparin is used as an anticoagulant to prevent and treat blood clots in at-risk patients. As a medication, it exists in two forms—unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH). Both forms considerably accelerate the inactivation of coagulation factor Xa by antithrombin, which is why heparin assays are often referred to as anti-Xa assays. The anticoagulant activity of UFH is somewhat unpredictable, whereas LMWH activity is more consistent.

The aPTT assay has traditionally been used to monitor UFH. However, the assay is fraught with inconsistencies. Alternative methods may be needed to monitor the variable and unpredictable nature of UFH to help guide dosing adjustments.

In this presentation, you’ll learn more about heparin monitoring and explore the use of aPTT and other anti-Xa assays in your clinical lab.

Learning Objectives

This webinar will help you:

• Describe the anticoagulant effects of heparin
• Explain the methods used to determine heparin levels
• Discuss the limitations of anti-Xa assays
• Formulate an approach for using anti-Xa assays to monitor anticoagulants

Fisher Healthcare is approved as a provider of continuing education programs in the clinical laboratory sciences by the ASCLS P.A.C.E.™ Program. One P.A.C.E.™ credit-hour will be provided for this complimentary basic level program.