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Test Code
HEPL
Test Name
Anti-Xa, Unfractionated Heparin
CPT Codes
85520
Expected Turnaround Time
1 day
Clinical Utility
Used to measure the amount of unfractionated 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 Specimen Collection and Processing Guidelines for Coagulation Testing.

Patient Preparation

This anti-xa test is for unfractionated heparin monitoring. Do not confuse order with anti-xa low molecular weight heparin (LMWH).
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: 0.30 - 0.70 IU/mL for venous thromboembolism and acute coronary syndrome  

Critical Values

HNL Lab Medicine Critical Values

Performing Location
Carbon Hospital, Cedar Crest Hospital, Dickson City Hospital, Hazleton Hospital, Hecktown Oaks Hospital, Muhlenberg Hospital, Pocono Hospital, Redeemer Health, Schuylkill Hospital
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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