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Test Code
LMWH
Test Name
Anti-Xa, Low Molecular Weight Heparin
CPT Codes
85520
Expected Turnaround Time
1 day
Clinical Utility
Used to measure the amount of low molecular weight heparin in the blood and to determine if the drug concentration is within the therapeutic range.
Specimen and Container Info

Specimen Type: Plasma

Collection Container: 1 Full Light Blue Top (Sodium Citrate)  
Collection Instructions

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.

Processing and Submission Instructions

Create platelet poor plasma according to the Specimen Collection and Processing Guidelines for Coagulation Testing.

Patient Preparation

This anti-xa test is for low molecular weight heparin monitoring. Do not confuse order with anti-xa unfractionated heparin (UFH).
Transport Instructions
  • Inpatient: Transport to the laboratory at room temperature.
  • Outpatient: Transport to the laboratory frozen. 
Stability Requirements

Room Temperature

1 hour

Frozen

Platelet poor plasma: 14 days
Causes for Rejection
  • Gross hemolysis
  • Clotted specimen
  • Specimen past stability
  • Specimen not properly filled
Methodology
Chromogenic Assay
Reference Intervals

Therapeutic Range: 0.50 - 1.00 IU/mL based upon peak levels 3-4 hours post subcutaneous injections while on a twice-daily dose regimen.
Performing Location
Cedar Crest Hospital, Muhlenberg Hospital
Alternate Names
  • Lovenox
  • Enoxaparin
  • Fragmin
  • Dalteparin
Testing Schedule
Routine daily, STAT testing available
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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