title: The use of anti-Xa assay to monitor intravenous unfractionated heparin therapy.
abstract: Continuous infusion unfractionated heparin (UH) has traditionally been monitored using the activated partial thromboplastin time (aPTT). The use of this test to monitor heparin therapy is not based on randomized controlled clinical trials, and the test is associated with significant intra- and inter-patient variability that is not related to circulating blood heparin activity. Due to these and other limitations, the use of aPTT alone to monitor UF has been questioned. Many laboratories are now transitioning to monitoring actual heparin activity (by anti-factor Xa analysis). In this review, we discuss the limitations of using the aPTT to monitor UH therapy and additionally the limitations of solely using heparin activity to monitor therapy. We also include a discussion of the challenges with monitoring heparin therapy in the pediatric population.
authors.affiliation: University of Florida, Gainesville, FL, USA. roseaf@shands.ufl.edu
authors.forename: Amy Fann
authors.initials: AF
authors.lastname: Rosenberg
authors.forename: Marc
authors.initials: M
authors.lastname: Zumberg
authors.forename: Lisa
authors.initials: L
authors.lastname: Taylor
authors.forename: Aimée
authors.initials: A
authors.lastname: LeClaire
authors.forename: Neil
authors.initials: N
authors.lastname: Harris
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000097:blood / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D016903:Drug Monitoring / Q000379:methods*; D015951:Factor Xa / Q000032:analysis*; D065427:Factor Xa Inhibitors; D006493:Heparin / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D010314:Partial Thromboplastin Time
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D006493:Heparin; D015951:Factor Xa