Factor Xa (Porcine) / Heparin Assay

Message
For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Samples must be received in the Special Coagulation department at the Sandridge location by 3:00pm for same day results.

If unable to process and properly store specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.

This test needs a completed Anticoagulant Drug List submitted with the specimen. For a copy of the 2 page form click here

 


Test Code
UFHXA


Alias/See Also
76058;
Factor Xa Level (UFH)
Anti-Xa Level (Porcine)
Heparin Assay (Level)


CPT Codes
85520

Preferred Specimen
1 plastic (2.7mL) completely filled 3.2% Sodium Citrate (light blue top) tube


Minimum Volume
2 Frozen Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)


Instructions
Use standard venipuncture and disposal techniques.
Collect the required quantity of Sodium Citrate (light blue top) tubes.

If unable to process specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.

Sodium Citrate (light blue top) tube: Process immediately (stable only 4 hours), following instructions below:
Note: We recommend aliquot tubes to be made of polypropylene plastic as this material is safe to freeze at <-70 degrees C.
1. Centrifuge capped Sodium Citrate (light blue top) tubes at 3000 rpm for 10 minutes, or at speed and time required to consistently produce Platelet Poor Plasma (<5/kmm3).
2. Carefully remove the plasma from all Sodium Citrate (light blue top) tubes; avoid disturbing the WBC/buffy coat, and combine all plasma into a plastic conical centrifuge tube.
Note: If the plasma shows any hemolysis, it must be recollected.
3. Centrifuge the plasma in the plastic conical centrifuge tube for a second time as in step 1.
4. In one smooth motion, carefully and quickly pour the centrifuged plasma into a second plastic conical centrifuge tube. A small amount of plasma along with a red cell button should remain on the bottom of the original conical tube if the pour was executed correctly.
Note: This quick-pour method prevents platelet transfer and contamination.
5. Aliquot at least 1mL of plasma into each aliquot tubes labeled “plasma.” Refer to the Minimum Volume section above for the number of aliquots required per test.
6. Finally, place all aliquots into a <-20°C freezer within 4 hours.
Note: Aliquots must remain frozen until they are picked up by the CompuNet courier. Call CompuNet transportation department if frozen specimen boxes are needed.


Transport Container
Whole blood Sodium Citrate (light blue top) tube
    OR
Frozen - Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)


Transport Temperature
Room Temperature: Whole blood Sodium Citrate (light blue top) tube
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (Po


Specimen Stability
Room Temperature: Whole blood Sodium Citrate (light blue top) tube < 4 hours
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tube whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended) <30 days at <−20 degrees C


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Rejected for hemolysis, clotted, improper fill, incorrect specimen type, thawed frozen aliquots, refrigerated plasma or blood, expired test tubes, >4 hours old if not processed into separated frozen plasma vials.


Methodology
Chromogenic Analysis

Setup Schedule
Monday - Friday
SCOAG


Report Available
Same day if received by 3:00pm Monday- Friday
When received after 3:00pm, results can be 1-3 days


Clinical Significance
Factor Xa is a quantitative determination of the level of UF heparin or Low Molecular Weight heparins (Fragmin and / or Lovenox ) in a patient’s plasma. The amount of heparin is specifically determined from the anti- Xa activity expressed by the Heparin-Antithrombin complex found in the plasma.


Performing Laboratory
CompuNet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine, OH 45439


Last Updated: August 17, 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.