Heparin, Low Molecular Weight, Anti Factor Xa

Message

See specimen stability for guidance when drawing specimens at a location other than McKee Medical Center, North Colorado Medical Center, or Banner Fort Collins Medical Center. STAT courier must be called for transport to the performing laboratory when stability is less than 24 hours.

Test Code

LMWH - NCMC

CPT Codes
85520

Preferred Specimen

Full blue top tube or 1.0 mL plasma frozen

Instructions

It is imperative that the tube be completely filled to frosted line. The ratio of blood to anticoagulant is critical for valid coagulation results. If obtaining blood with a syringe, fill the light blue-top (sodium citrate) tube first.
If patient is on heparin, specimen must be centrifuged and separated within 1 hour of draw.
Heparin contaminated tube is not acceptable.
Keep specimen anaerobic.
Patients with an extremely high hematocrit may require special tubes before obtaining blood for coagulation testing. Please contact the lab for further information.
If testing will not be completed within 1 hours, spin down, remove plasma, and spin plasma again, and send specimen frozen in plastic vial.

Specimen Stability

Specimen Type	Temperature	Time
NaCit – Full Tube	Ambient	4 hours
NaCit – Full Tube	Refrigerated	4 hours
NaCit Plasma	Frozen	2 weeks

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

Clotted
Serum received instead of Sodium Citrate plasma
Specimen past stability
Frozen plasma received thawed
Underfilled or Overfilled, blood/anticoagulant ratio must be 9/1; Specimens must be between 90% -110% full
Collected in a 3.8% Sodium Citrate tube instead of 3.2% Sodium Citrate tube
Drawn in outdated/expired tube
Hemolyzed, icteric, or lipemic sample

Setup Schedule

Monday through Sunday; Continuously

Report Available

Same Day

Reference Range

Therapeutic range for low molecular weight heparin varies with the brand and manufacturer, but is typically between 0.6-1.00 IU/mL.

Critical value (automatic call-back): >1.5 IU/mL

Note: Major institutions have shown that the most common reason for a sub therapeutic level is specimen not drawn at the proper time (4 hours post injection).

Clinical Significance

Note: Occasions in which periodic monitoring of LMWH might be considered include renal failure, pregnancy (increased dosage requirement in the third trimester), pediatric patients (increased dosage requirement in newborns), obesity, underweight patients, prolonged use, or patients at high risk for bleeding or thrombosis

Performing Laboratory
North Colorado Medical Center Laboratory
McKee Medical Center Laboratory
Banner Forth Collins Medical Center 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.