Heparin, Anti-Xa
Test Code
Clinical Significance
Heparin, Anti-Xa - This assay is useful in measuring heparin concentration in patients treated with low molecular weight heparins (i.e. Enoxaparin/Lovenox) or unfractionated heparin. It is not intended for measurement of Rivaroxaban (Xarelto) or Fondaparinux (Arixtra).
Refer to test code 90981 for Rivaroxaban measurement and test code 16103 for Fondaparinux measurement.
Test Resources
Test FAQ
Heparin, Anti-XaTest Details
Methodology
Reference Range(s)
| UFH Therapeutic Range | 0.30-0.70 IU/mL |
LMWH Therapeutic Ranges (target anti-Xa levels measured 4 hours after dosing):
| Enoxaparin (Lovenox) | |
| Therapeutic bid dosing | 0.6-1.0 IU/mL |
| Therapeutic qD dosing | >1.0 IU/mL |
| Tinzaparin (Innohep) | |
| Therapeutic qD | 0.85 IU/mL |
| Dalteparin (Fragmin) | |
| Therapeutic qD | 1.05 IU/mL |
For more information on this test, go to: http://education.questdiagnostics.com/faq/FAQ53v1 (This link is being provided for informational/ educational purposes only.)
Alternative Name(s)
Preferred Specimen(s)
2 mL frozen plasma collected in 3.2% sodium citrate (light blue-top) tube
Minimum Volume
1 mL
Collection Instructions
Platelet-poor plasma: Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/uL). Freeze immediately and ship on dry ice.
Transport Container
Transport tube
Transport Temperature
Frozen
Specimen Stability
- Room temperature: Unacceptable
- Refrigerated: Unacceptable
- Frozen: 30 days
Reject Criteria
Hemolysis
Setup Schedule
Refrigerated: Unacceptable
Frozen: 30 days