Specimen Requirements

Involves special collection requirements. Kits for drawing this test have been supplied to the units that will be ordering the test. The kits include 2.0 mL Greiner Bio-One partial fill vacuette tubes with 3.2% sodium citrate (blue top tube), a discard tube and instructions for collection. 

Collection Instructions: 

• Draw 2 Greiner blue-top tubes using a 21-gauge needle to the black line on the tubes (1/2 tube). Do not underfill.  
• Invert gently 5 times to mix blood. 

Specimens cannot be sent through the pneumatic tube system. They must be hand delivered to the lab.  

Testing must be completed within 4 hours of collection.  

Note: Limitations of the test include interference by other antiplatelet drugs such as Glycoprotein IIb/IIIa inhibitors. Patients who have been treated with Glycoprotein IIb/IIIa drugs should not be tested until platelet function has recovered. This time period is approximately 14 days after discontinuation of drug administration for abciximab (Reopro) and up to 48 hours for eptifibatide (Integrilin) and tirofiban (Aggrastat). The platelet function recovery time varies among individuals and is longer for patients with renal dysfunction. NSAIDs (e.g. ibuprofen) or anti-platelet drugs like Aggrenox (aspirin/extended-release dipyridamole), Persnatine (dipyridamole), and Pletal (citostazol) can also interfere with test results. The effect of hematocrits less than 29%, hematocrits greater than 56%, platelet counts less than 92,000 per microliter, fibrinogen less than 164 mg/dL and fibrinogen greater than 529 mg/dL have not been tested.