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.

Instrumentation changed from BCS-XP to CS-5100 on 12/16/2019.
Methodology:
Anti Xa activity by chromogenic substrate without antithrombin supplementation.

Assay updated to Siemens Innovance reagent on 03/05/19.
Sample Processing:
Centrifuge within four hours of draw time.
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells.
Separate plasma into plastic container and cap (glass is not acceptable).
Centrifuge a second time to ensure platelet poor plasma and separate plasma into a new, labeled plastic tube, cap.
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.
CPT Code:
85520