Test Code LMW Hep Low Molecular Weight Heparin Assay
Aliases
Anti-Xa
Useful For
Low molecular weight heparins (LMWH) are used for the prevention and treatment of thromboembolic diseases. The quantitative determination of LMWH are useful for monitoring treatment efficacy.
Patient Preparation
No special patient preparation required
Special Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate tube
Collection Method
Venous Draw; properly filled 9:1 ratio (blood to anticoagulant)
Minimum Volume
0.5 ml of plasma from a properly filled 1.8 mL or 2.7 mL NaCitrate (light blue) tube
Container
Light Blue Sodium Citrate
Preferred Specimen
2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable Specimens
1.8 mL Lt. Blue (3.2% NaCitrate) tube
Reference or Target Ranges
Low Dose: 0.2 – 0.4 Anti-Xa units/mL
High Dose: 0.6 – 1.1 Anti-Xa units/mL
Reportable Units
IU/mL
Critical Value
Not defined for this assay
Reasons for Rejection
Hemolysis Threshold | If visible – reject |
Icterus Threshold | If visible – reject |
Lipemia Threshold | If visible – reject |
Interfering Subtances/Other | Short draws, over draws, clotted, improperly labeled, hemolyzed, lipemic or icteric samples, samples > 4 hours from collection |
Specimen Stability
Ambient | 4 hrs; Must be spun within 1 hour of collection |
Refrigerated (4°C to 8°C) | N/A |
Frozen(-700°C to 00°C) | 15 Days@ -20°C; 1 year @ -70°C |
Performance Information
Days and Time Performed | 24/7 |
Expected Turn Around Time | Stat:1 hour on arrival to lab Routine:4 hours on arrival to lab |
Stat Availability | Yes |
Performing Bench | Coagulation |
Methodology/Method Description | UH: Werfen ACL TOPS |
Special Handling
Once sample is received in Lab- testing must be performed on Platelet Poor Plasma
Additional Information/Important Notes
Specimen will be rejected if received in laboratory > 1 hour after collection.
CPT Codes
85520