Hemostasis 1 (Tesse) Flashcards
(20 cards)
What is hemostasis
interactive process between blood vessels, platelets, coagulation proteins and fibrinolytic system. Stops bleeding
steps of hemostasis
1 vascular injury
2 vasospasm and vasoconstriction
3 platelet plug formation
4 coagulation
5 clot retraction and fibrinolysis
What does primary hemostasis refer to
formation of a platelet plug
steps of primary hemostasis
1 adhesion
2 shape change
3 granule release
4 recruitment
5 aggregation and platelet plug formation
What are clinical signs of a primary hemostasis disorder
superficial hemorrhage
epistaxis
melena, hematochezia
urinary tract hemorrhage
thrombocytopenia
thrombocytopathia
What qualifies as thrombocytopenia
< 2-3 platelets/hpf
what are the three acquired causes of thrombocytopenia
- increased consumption
- increased destruction
- decreased production
Give an example of increased destruction of platelets
immune mediated thrombocytopenia
what are some causes of secondary IMT
post vx, drugs, rickettsial dz, neoplasia
give an example of increased consumption of platelets
DIC, thrombosis or vasculitis
What are the top three common causes of acquired thrombocytopenia
IMT
drug-induced BM suppression
other causes of decreased platelet production (neoplasia, myelopthisis)
what is congenital thrombocytopenia NOT associated with
hemorrhage, clinical signs
what breeds are predisposed to congenital thrombocytopenia
CKCS, chihuahuas, labs, poodles, shih tzus, maltese, jack russels
What is an example of thrombocytopathia
von Willebrand disease
What is von willebrand disease
extrinsic disorder caused by deficiency of functional vWF
what is the most common hereditary bleeding disorder of dogs, pigs, and people
von willebrand disease
what is vWD type 1
decreased vWF proteins with normal structure and function
what is vWD type 2
decreased vWF proteins with abnormal structure and function
what is vWD type 3
markedly reduced or absent vwf
What are tests for primary hemostasis
- cbc platelet count
- buccal mucosal bleeding time
- bone marrow aspirate
- vwf antigen assay
