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Aspirin Reaction Units
Test CodeLAB6734
Alias/See Also
ARU; Aspirine reaction Units
CPT Codes
85576
Preferred Specimen
2-mL Griener Bio-One Vacuette tubes (whole blood Sodium Citrate Plasma)
2 Full tubes and 21 gauge or larger needle should be used
Do Not centrifuge
2 Full tubes and 21 gauge or larger needle should be used
Do Not centrifuge
Patient Preparation
Samples should be collected 2 to 30 hours after ingestion of aspirin to show drug effect.
Minimum Volume
2 Full tubes
Instructions
Attention to collection procedure is necessary to avoid inaccurate results, collect as follows:
1. Draw a discard tube (at least 2 mL).
2. Draw 2 Griener blue-top tubes. Do not overfill or under fill.
Greiner Bio-One Vacuette (3.2% Sodium Citrate)
Gently invert tube at least 5 times to ensure complete mixing of contents.
3. Forward promptly at ambient temperature. Do not send Greiner blue-top tube through the pneumatic tube system.
1. Draw a discard tube (at least 2 mL).
2. Draw 2 Griener blue-top tubes. Do not overfill or under fill.
Greiner Bio-One Vacuette (3.2% Sodium Citrate)
Gently invert tube at least 5 times to ensure complete mixing of contents.
3. Forward promptly at ambient temperature. Do not send Greiner blue-top tube through the pneumatic tube system.
Transport Container
Primary Container
Transport Temperature
Room Temp
Specimen Stability
3 hours at ambient temperature.
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Avoid hemolysis and heparin contamination of specimen. Clotted blood or an insufficient specimen is not acceptable.
Specimens received via pneumatic tube system.
Specimens received via pneumatic tube system.
Methodology
Turbidimetric Based Optical Detection System
Note: The assay detects aspirin inhibition of platelet aggregation due to irreversible acetylation of cyclo-oxygenase-1 and reduced thromboxane A2 synthesis.
Setup Schedule
Daily, Stat Available
Report Available
2-4 hours after receipt in the laboratory
Limitations
Patients with HCT<20% or PLT<50 K/uL cannot be tested with the VerifyNow Assay.
Results could be affected by the following: GPIIb/IIIa inhibitors, low HCT, low PLT or inherited platelet disorders.
Test performance was not affected by hematocrit values between 29-56%, or platelet count values of
≥ 92,000/μL or moderate to extensive blood hemolysis induced by physical manipulation.
This test is not used for patients with underlying congenital platelet abnormalities, patients with non-aspirin induced acquired platelet abnormalities or in patients receiving non-aspirin anti-platelet agents
Patients with inherited platelet disorders such as von Willebrand Factor Deficiency, Glanzmann Thrombasthenia and Bernard-Soulier Syndrome have not been studied with the VerifyNow Aspirin Test.
Patients who have taken a GP llb/llla inhibitor drug should not be tested until the platelet function has recovered. For Eptifibatide (Integrilin®) and tirofiban (Aggrastat) drug, administration should be discontinued approximately up to 48 hrs, or abciximab (ReoPro®) approximately 14 days.
Results could be affected by the following: GPIIb/IIIa inhibitors, low HCT, low PLT or inherited platelet disorders.
Test performance was not affected by hematocrit values between 29-56%, or platelet count values of
≥ 92,000/μL or moderate to extensive blood hemolysis induced by physical manipulation.
This test is not used for patients with underlying congenital platelet abnormalities, patients with non-aspirin induced acquired platelet abnormalities or in patients receiving non-aspirin anti-platelet agents
Patients with inherited platelet disorders such as von Willebrand Factor Deficiency, Glanzmann Thrombasthenia and Bernard-Soulier Syndrome have not been studied with the VerifyNow Aspirin Test.
Patients who have taken a GP llb/llla inhibitor drug should not be tested until the platelet function has recovered. For Eptifibatide (Integrilin®) and tirofiban (Aggrastat) drug, administration should be discontinued approximately up to 48 hrs, or abciximab (ReoPro®) approximately 14 days.
Reference Range
≥ 550 ARU Platelet dysfunction consistent with aspirin has not been detected.
< 550 ARU Platelet dysfunction consistent with aspirin has been detected.
Reference Range
≥ 550 ARU
Clinical Significance
The VerifyNow® Aspirin Test is a qualitative test to aid in the detection of platelet dysfunction due to aspirin (ASA) ingestion in citrated whole blood.
Performing Laboratory
CHOMP Laboratory
