Aspirin Reactivity Units
Label Mnemonic: | ARU |
Epic code: | LAB8084 |
Downtime form: | Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Hematology
6240 RCP
356-3527
6240 RCP
356-3527
Specimen(s):
Whole Blood
Specimen
Instructions:
Must be drawn in special sodium citrate tubes. Call Tech
Services (356-3527) for collection kit.
Minimum:
Must be collected in a (2 mL) special collection tube.
Rejection Criteria:
If specimen is over 4 hours old and not drawn in special collection
tubes. Improper sample collection (platelet activation) or patient's
exposure to other anti-platelet agents.
Delivery Instructions:

Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around
Time:
1 hour (upon receipt in laboratory)
Reference Range:
620-672 ARU (pre-drug administration) Therapeutic range: <550 ARU
Interpretive Data:
<550 ARU.
Platelet dysfunction consistent with aspirin has been detected.
Patients who have been treated with Glycoprotein IIb/IIIa inhibitors should not be tested until platelet function has recovered. This time period is approximately 14 days after discontinuation of abciximab (ReoPro) and up to 48 hours after discontinuation of eptifibatide (Integrilin) and tirofiban (Aggrastat).
Platelet dysfunction consistent with aspirin has been detected.
Patients who have been treated with Glycoprotein IIb/IIIa inhibitors should not be tested until platelet function has recovered. This time period is approximately 14 days after discontinuation of abciximab (ReoPro) and up to 48 hours after discontinuation of eptifibatide (Integrilin) and tirofiban (Aggrastat).
Test
Limitations:
Improper sample collection (platelet activation) or patient's exposure
to other anti-platelet agents.
Test performance has only been validated for hematocrit values between 29-56% and platelet counts ≥ 92 K/MM3. Patients with hematocrits or platelet counts outside of these ranges may generate unreliable results.
Test performance has only been validated for hematocrit values between 29-56% and platelet counts ≥ 92 K/MM3. Patients with hematocrits or platelet counts outside of these ranges may generate unreliable results.
Methodology:
The VerifyNow system incorporates the agonist arachidonic acid to
activate platelets.
CPT Code:
85576