Heparin Anti-Xa

Test Code

38433

CPT Codes
85520<br>Limited Access Code

Preferred Specimen

2 mL platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tube

Minimum Volume

1 mL

Instructions

Platelet-Poor Plasma: Centrifuge light blue-top tube 15 minutes at approx. 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/mcL). Freeze immediately and ship on dry ice.

Note: Double-centrifuged specimens are critical for accurate results as platelet contamination may cause under-estimation of heparin level.

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Methodology
Chromogenic

Setup Schedule

Set up: Mon-Sat; Report available: Next day

Reference Range

See Laboratory Report

Clinical Significance

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.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.