Primary hemostasis
Platelets and platelet function
- vessels
Secondary
Coagulation
Tertiary
Fibrinolysis
_____ plays a role in all 3 parts of hemostasis
Vessel
If endothelial cells are quiescent, they will _____ primary and secondary and _____ tertiary
Inhibit; enhance
- once activated, they enhance primary and secondary and inhibit tertiary
Platelet - structure
Small fragments of megakaryocyte cytoplasm
Platelet - granules
Megakaryopoiesis and thrombopoiesis
Thrombopoietin and other cytokines
Thrombopoietin
Reticulated platelets
Platelet concentration
Blood smear
- morphologic abnormalities
Platelet sample
Platelet count
Mean platelet volume
Varies between analyzer, anticoagulant and storage time
- presence of cell fragments and large platelets
Thrombocytopenia
Concentration is lower than the LRL
Thrombocytopenia less than 30,000/uL
- mucosal bleeding (epistaxis, hematochezia, melena), hematuria, hyphema
Pseudo-thrombocytopenia
Thrombocytopenia - shift/sequestration
Thrombocytopenia - decreased production
- idiopathic thrombocytopenia of CKCS –> maybe due to lack of production
Thrombocytopenia - decreased production due to drugs
Thrombocytopenia - decreased production due to infection
Multifactorial, often include decreased production
Thrombocytopenia - decreased production due to marrow replacement
Myelophthisis
Thrombocytopenia - destruction
Immune mediated thrombocytopenia