Heparin Assay (Unfractionated Heparin Anti Xa)
| Label Mnemonic: | HEP |
| Epic code: | LAB317 |
| Order form: | Laboratory Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 85520 |
Specimen(s):
Citrated Plasma More information
Collection Medium:
 |
| Light Blue top tube 1.8 mL (Na Citrate) |
Minimum:
Full draw; 1.8 mL light blue top (3.2% sodium citrate) tube. Mix well.
Testing
Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around
Time:
2 hours (upon receipt in laboratory)
Comments:
Site of anticoagulant infusion and site of blood collection must be entered at time of collection.
Recommended target range for treatment of DVT or venous thromboembolism is 0.4-0.7 U/mL.
Double-centrifuged specimens are critical for accurate results as platelet contamination may cause spurious results.
High doses of unfractionated heparin with low anti-Xa results could be due to low antithrombin activity.
Methodology:
Anti Xa activity by chromogenic substrate without antithrombin supplementation.
Assay updated to Siemens Innovance reagent on 03/05/19.
Sample
Processing:
Double-centrifuge specimen to prepare platelet-free plasma.
Immediately centrifuge specimen at 3500 RPM for 12 minutes.
Using a plastic transfer pipette, carefully remove plasma from cells avoiding the platelet/buffy coat.
Place plasma into a labeled plastic tube.
Centrifuge plasma again at 3500 RPM for 12 minutes.
Remove the top of the plasma and place into a labeled plastic tube.
Freeze double-spun plasma within 4 hours of collection time at -20 degrees C or below.
Immediately centrifuge specimen at 3500 RPM for 12 minutes.
Using a plastic transfer pipette, carefully remove plasma from cells avoiding the platelet/buffy coat.
Place plasma into a labeled plastic tube.
Centrifuge plasma again at 3500 RPM for 12 minutes.
Remove the top of the plasma and place into a labeled plastic tube.
Freeze double-spun plasma within 4 hours of collection time at -20 degrees C or below.
Sample
Storage:
Freeze specimen immediately.
Transport
Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in Styrofoam container to maintain frozen temperature.
Samples received thawed will be cancelled.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in Styrofoam container to maintain frozen temperature.
Samples received thawed will be cancelled.