Platelet disorders

• Can have normal #, but abnormal function
  • Bernard-Soulier
  • Glanzmann Thrombasthenia
• If have low # of platelets:
  • Poor production from bone marrow
  • Sequestration by large spleen
  • Destruction: By antibodies, or by abnormal intravascular clotting

Platelet Function Disorders:

• Glanzmann Thrombasthenia
• Bernard-Soulier Syndrome

Thrombocytopenias

• TAR syndrome
• ITP
• Wiscott-Aldrich Syndrome
• Kasabach-Merrit Syndrome
• HUS
• Uremia, FDP, Aspirin and other meds can cause platelet dysfunction

PFA –100

• Measures bleeding time in vitro
• Measures time required for blood sample to form platelet plug that then occludes an aperture in the system

Thrombin Clotting Time

• Measures patients ability to convert fibrinogen to fibrin by adding bovine thrombin to the in vitro system
• Abnormal in cases of dyfunctional fibrin and heparin

CHLA Board Review 2005
American Academy of Pediatrics. PREP The Curriculum Pediatric Review and Education Program, 1997-present
2.BehrmanRE,Kliegman RM, Jenson HB. Nelsons Textbook of Pediatrics. 16thedition. WB Saunders Company, Philadelphia, 2000
3.JourneycakeJM, Buchanan GR. “Coagulation Disorders” Pediatrics in Review, Vol. 24, No.3, March 2003
4.Nathan DG, OrkinSH, Ginsburg D, Look AT. Nathan and Oski’sHematology of Infancy and Childhood. 6thedition. WB Saunders Company, Philadelphia, 2003