• See Also
  1. Platelet Count
  2. Complete Blood Count
  3. Platelet Morphology on Peripheral Smear
  4. Mean Platelet Volume
  5. Platelet Function Closure Time
  6. Bleeding Disorder
  7. Clotting Cascade
  • Indication
  1. Bleeding Disorder
    1. Replaced by von specific tests (Willebrand Factor Activity, Von Willebrand Factor Antigen, Factor VIII Level)
  2. Historical indications
    1. Replaced Bleeding Time to assess Platelet function
    2. Personal or Family History of easy Bruising or bleeding
      1. Epistaxis
      2. Menorrhagia
      3. Post-operative bleeding
  • Protocol
  • Sample
  1. Citrate anticoagulated whole blood
  • Mechanism
  1. Rapid quantitation of Platelet function for Hemostasis
  2. Blood passed through high shear flow system
  3. System measures time to occlude membrane
  4. Blood is tested with two membranes
    1. Collagen/Epinephrine (CEPI) membrane
    2. Collagen/Adenosine Diphosphate (CADP) membrane specific for Aspirin
  • Interpretation
  • Normal
  1. CEPI closure <175
  • Causes
  • Abnormal (prolonged closure time)
  1. Von Willebrand's Disease
  2. Glanzmann's Thrombasthenia
  3. Thrombasthenia
  4. Thrombocytopenia with Platelet Count <100,000/mm3
  5. Anemia with Hematocrit <35%
  6. Aspirin (will prolong only the CEPI membrane time)
  • References
  1. Harrison (2002) Clin Lab Haematol 24: 225-32 [PubMed]
  2. Serebruany (2006) J Thromb Haemost 4:1429-31 [PubMed]