-
Important role in primary hemostasis and formation of hemostatic plug. Produced by fragmentation of megakaryocytes in bone marrow, lung and spleen.
-
Lifespan 7-10 days with 30% of the pool transiently sequestered in spleen.
-
Normally 200,000-500,000 in numbers and in spontaneous hemorrhage it goes < 30,000.
-
Platelet disorders are evident through findings such as petechia, ecchymosis, mucosal bleeding, pale mucosa, epistaxis, hematuria, organomegaly.
-
Careful venipuncture, blood smear, platelet count, coagulation factor tests (PT, PTT, ACT, ATIII to r/o DIC), bone marrow exam, ANA, Coombs, platelet function tests (platelet aggregation, bleeding time, vWD).
-
Thrombocytopenia from decreased production (bone marrow problem), increased destruction (IMT, drug induced, infectious), increased utilization (DIC, vasculitis, septicemia), sequestration (milder, spleno/hepatomegaly).
|