Heparin Xa, Unfractionated

Test Code

HEPAR

Alias/See Also

Xa Heparin, UHF, Heparin assay, XA, Heparin XA

CPT Codes
85520

Preferred Specimen

Citrate (BLU)

Instructions

Collect whole blood in 3.2% buffered sodium citrate (9:1 blood to sodium citrate). Venipuncture must be atraumatic.

Specimen Stability

Centrifuge at the appropriate time and RPM's for the plasma to have a platelet count less than 10,000. Plasma platelet count should be less than 10,000. Test within two hours of collection.
If testing is to be delayed more than four hours after collection, immediately separate plasma into clean polystyrene tube, cap, and store below –20°C up to two weeks or -70° C up to 6 months.
In patients with hematocrit values greater than 55%, the citrate concentration must be adjusted so that a proper plasma/anticoagulant volume is maintained.

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

Reject hemolyzed, clotted, overfilled tubes or short draw (<90%) samples.

Setup Schedule

24x7

Reference Range

Recommended therapeutic range for heparinization is 0.3 - 0.7 IU/ml.

Clinical Significance

Heparin is a drug that inhibits blood clotting (anticoagulant) and is used to treat people who have developed dangerous blood clots (thrombi) or have a high risk of developing them. This test indirectly measures the amount of heparin in a person's blood by measuring its inhibition of factor Xa activity, one of the proteins involved in blood clot formation (known as heparin anti-Xa activity).

The test is used to monitor heparin.

Performing Laboratory
CRMC Laboratory

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.