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|Performed by||Parnassus Hematology|
|In House Availability||Monday - Friday 0800-1600|
|Method||Chromogenic anti-factor Xa|
|Collection Instructions||1. Check the expiration date on the label of the blue top vacutainer before drawing the patient.
2. For blood collection in a sodium citrate blue top, the tube must be filled to above the Minimum Fill Indicator on the tube. It is crucial to wait and allow the tube to stop filling before removing it from the needle.
3. With use of a butterfly needle, draw about 1 cc using a separate blue top to remove air from tubing, discard the first tube and then draw a second blue top tube filled to the full extent of the vacuum.
4. Tubes should not be filled past the Maximum Fill dashed line by either using a syringe or removing the tube cap.
|Container type||Blue top filled to full extent of vacuum|
|Amount to Collect||2.7 mL|
|Preferred volume||1 mL|
|Min. Volume||0.5 mL|
|UCSF Rejection Criteria||Samples collected in outdated blue top vacutainer. Over-filled or under-filled tubes may be rejected.|
|Processing notes||Deliver immediately to Hematology for processing.|
|Normal range||See additional information|
|Critical value||> 1.26 µg/mL|
|Stability||Room temperature 4 hours|
|Turn around times||1-3 days for routine requests|
|Additional information||Although the manufacturer DOES NOT provide recommendations for a therapeutic range, the manufacturer provides the following information regarding observed drug levels in individuals treated with fondaparinux (Prescribing information from Glaxo Smithkline, 2008). Values in these ranges may be expected when fondaparinux is measured.
Prophylactic dose: 2.5 mg, once daily.
Peak steady-state plasma concentration: 0.39-0.50 micrograms/mL (3 hours post-dose)
Minimum steady-state plasma concentration: 0.14-0.19 micrograms/mL.
Therapeutic dose: 5 mg (body weight <50 kg), 7.5 mg (body weight 50-100 kg) or 10 mg (body weight >100 kg) once daily.
Peak steady-state plasma concentration: 1.20-1.26 micrograms/mL (3 hours post dose)
Minimum steady-state plasma concentration: 0.46-0.62 micrograms/mL.
The manufacturer recommends that if during therapy with fondaparinux, unexpected changes in coagulation parameters or major bleeding occurs, fondaparinux should be discontinued.
|LDT or Mod FDA?||Yes|
|Last Updated||11/27/2012 5:24:14 PM|
If you have additional questions regarding this test, please call: 415-353-1667