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HelpHeparin Anti-Xa
Specimen Requirements
Specimen Type: Whole blood
Container/Tube: Light-blue top (sodium citrate)
Specimen Volume: Full tube
Specimen Minimum Volume: 2.7 mL
Collection Instructions:
1. Tube must be full. (Do not underfill or overfill tube.)
2. Send specimen Room Temperature in original tube.
Stability
Test within 4 hours or freeze plasma
Reference Range
Therapeutic anti–Xa ranges depend on the type of heparin and the clinical context.
For intravenous unfractionated heparin (UFH), the therapeutic range is 0.3–0.7 IU/mL.
For low molecular weight heparin (LMWH):
Prophylactic dosing: 0.2–0.5 IU/mL
Therapeutic dosing (BID): 0.5–1.0 IU/mL
Anti–Xa levels should be drawn 4 hours after dosing (acceptable sampling window 3–5 hours post-dose).
Instrumentation
Sysmex CA660
Methodology
Photo-Optical
Test Schedule/Analytical Time/ Test Priority
Daily / Same day / Available STAT
CPT (s)
85520