Contents

Search

coagulation factor X inhibitor in plasma; anti-factor Xa heparin assay

Indications: - evaluation for coagulation factor inhibitor, generally factor X autoantibody - heparin therapy in patients: a) with lupus anticoagulant b) also taking warfarin c) refractory to heparin (> 40,000 units/day) d) receiving thrombolytic therapy Reference interval: - < 0.1 anti-Xa heparin units/mL - therapeutic unfractionated heparin: - 0.3 - 0.7 anti-Xa units/mL - prophylactic unfractionated heparin: - 0.2-0.4 anti-Xa units/mL - LMW heparin: - 0.5 - 1.0 anti-Xa units/mL (4 hours post dose, BID dosing) - 1.0 - 2.0 anti-Xa units/mL (4 hours post dose, QD dosing) - 0.2 - 0.4 anti-Xa units/mL plasma (4 hours post dose, prophylaxis) Method: - test does NOT depend upon phospholipid Specimen: - citrated plasma

Related

coagulation factor X autoantibody coagulation factor X; Stuart factor; Stuart-Prower factor; contains: factor X light chain; factor X heavy chain; activated factor Xa heavy chain (F10)

General

clinical coagulation test

References

  1. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
  2. UAB Coagulation Service http://peir.path.uab.edu/coag/article_23.shtml
  3. Heparin Assay to Monitor Unfractionated Heparin http://www.universityhealthsystem.com/files/11-Heparin%20Monitoring%20Change%20(Formulary%20Flash%20from%20May%202009%20describing%20assay%20change%20by%20the%20Lab)%20.pdf
  4. Levine MN et al A randomized trial comparing activated thromboplastin time with heparin assay in patients with acute venous thromboembolism requiring large daily doses of heparin. Arch Intern Med. 1994 Jan 10;154(1):49-56. PMID:8267489