HEPARIN ANTI Xa, UNFRACTIONATED HEPARIN

Message

Sample should be centrifuged within 1 hour of collection using the Platelet-Poor technique. See Additional Information below for instructions.
This test cannot be used to monitor Rivaroxaban (Xarelto) or Fondaparinux (Arixtra) therapy.

Test Code

HXAUF

CPT Codes
85520

Preferred Specimen

1 Blue tube (Sodium Citrate)

Minimum Volume

0.5 mL

Other Acceptable Specimens

None

Instructions

Centrifuge specimen within one hour of collection. Transport 2 mL platelet-poor plasma (minimum 0.5 mL).

Transport Temperature

Frozen

Specimen Stability

Plasma separated from cells is stable:

15-30°C up to 4 hours
-20°C up to 2 weeks
-70°C up to 6 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

The following conditions will result in a rejected sample:

Serum, EDTA Oxalate, Heparin, or Plasma separator tubes

Specimens ambient (room temperature) more than 4 hours

Hemolyzed, icteric, or lipemic specimen

Specimen submitted refrigerated

Whole blood specimens not centrifuged within 4 hours

Methodology
Chromogenic assay

Setup Schedule

M, Tu, W, Th, F, Sa, Su

Report Available

Within 24 hours of receipt at the performing laboratory.

Reference Range

0.3 - 0.7 IU/mL

Clinical Significance

The Heparin Anti-Xa Low Molecular Weight test is used to monitor and adjust standard heparin (unfractionated heparin, UFH) therapy. The preferred test for monitoring UFH is the APTT test, however this test may be used to monitor patients who have "heparin resistance" and do not respond as expected to UFH. In addition, underlying conditions such as liver dysfunction or interfering factor(s) such as Lupus Anticoagulant interfere with the PTT test and render it ineffective.

This test cannot be used to monitor Rivaroxaban (Xarelto) or Fondaparinux (Arixtra) therapy.

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NHMC (Hematology, IL Coag)

Additional Information
Obtaining A Platelet-Poor Specimen

Last Updated: June 9, 2023

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.