Test Code LABHEPXA Heparin Anti-Xa Assay
Additional Codes
| Test Name in EPIC | EPIC Test Code | Mnemonic |
|---|---|---|
| HEPARIN ANTI-XA ASSAY | LABHEPXA | HEPXA |
Methodology
Chromogenic Assay
Specimen Requirements
Fill Blue top tube to the etched line located just below the cap of the tube.
Light-blue top (3.2% sodium citrate)
1. Draw patien 6 hours after start of infusion and then 6 hours after each change.
2. To monitor Enoxaparin (Lovenox) therapy, draw for peak 4-6 hours post dose.
Specimen Transport Temperature
1. To achieve platelet-poor plasma, spin down, remove top 2/3 of plasma, and spin plasma again in a plastic vial.*
2. Aliquot top 3/4 and place platelet-poor plasma in a plastic transport vial.*
3. Glass vials are not acceptable for processing/transport/storage.
4. Stable for 2 hours at room temperature
5. Preferred specimen volume: 1 mL sodium citrate plasma
6. Minimum specimen volume: 0.5 mL sodium citrate plasma
* 2 Aliquot labels will auto print at non-performing sites to double spin
Day(s) Test Set Up
Monday through Sunday (all shifts)
Performing Laboratory
Coagulation-
Deer River Hospital Lab, Northern Pines Lab, Sandstone Hospital Lab, SMDC Clinical Lab, St. Joseph's Medical Center Lab, St. Mary's Hospital - Superior Lab, Virginia Hospital Lab
Ada Hospital Lab, Fargo Hospital Lab, Fosston Hospital Lab, Holy Trinity Hospital Lab, St. Mary's - Detroit Lakes Hospital Lab
Test Classification and CPT Coding
85520
Reference Values
Therapeutic Ranges:
Range: IU/mL
Comments: This test is not validated for other direct Xa inhibitor drugs (e.g. Rivaroxaban, Apixaban, etc.)
*Unfractionated Heparin:
Therapeutic range may vary from 0.2 to 0.7 IU/mL. The upper and lower limit of therapeutic range varies based on intensity (indication), see dosing nomogram.
*Low Molecular Weight Heparin:
Enoxaprin (Lovenox): 0.6 to 1.0 IU/mL (for 1mg/kg twice daily dosing), 1 to 2 IU/mL (for 1.5 mg/kg once daily dosing)
**Other LMWH products may yield different therapeutic ranges. Please consult drug product insert for appropriate range.