Flashcards in Secondary Hemostasis Deck (35)
_______ binds the platelet to VWF while _________ binds platelets to platelets (allowing aggregation)
What is the end product of the coagulation cascade
what does thrombin do?
convert fibrinogen to fibrin
What does fibrin do?
Where are the factors of the coagulation cascade produced?
What 3 things do coagulation factors require for activation?
1) exposure to activating substance
2) phopholipid surface
3) calcium (derived from platelets)
What is the cause of secondary hemostasis?
What are the clinical features of secondary hemostasis disorders?
deep bleeding (into muscles and joints)
What does PT measure?
extrinsic and common pathway
What does PTT measure?
intrinsic and common pathways
(intrinsic has more factors involved, measured by the test with more letters)
The goal of the coagulation cascade is to produce __________
factor 10 (the perfect 10)
What activates factor 12?
What activates factor 7?
What initiates the extrinsic pathway?
What test is a better measurement for the heparin effect?
What test is a better measurement for coumadin effect?
What is the cause of hemophilia A?
genetic deficiency in factor 8 (aaaaate)
X-linked recessive (can get de novo mutations)
What are the signs and symptoms of patients with disorders of secondary hemostasis?
deep tissue, joint, and postsurgical bleeding
What are the lab findings for disorders of secondary hemostasis?
1) HIGH PTT, normal PT
2) LOW factor 8
3) normal platelet count and bleeding time
What is the treatment for hemophilia A?
recombinant factor 8
What is the cause of hemophilia B?
factor 9 deficiency
How does hemophilia B look clinically?
the same as A! (both affect intrinsic pathway)
What is the most common coag factor inhibitor?
(resembles hemophila A)
how do you determine the difference between hemophilia A or coag factor inhibitor disease?
What is a mixing study?
mix normal plasma with patient plasma
What would the mixing study look like for hemophilia A?
can regain coagulation
What does mixing study look like for coag factor inhibitor?
FAILS, antibody will hit normal plasma too and it won't bind (cannot correct PTT)
What is Von Willebrand's Disease?
defect in VWF (MOST COMMON INHERITED COAG DISORDER)
What do lab findings look like for VWF disease?
1) HIGH bleeding time
2) HIGH PTT, normal PT
3) abnormal ristocetin test
lack of stability of factor 8 to change the labs but NOT to create clinical problems
What is the treatment of VWF disease?
desmopressin (increases release of VWF from Weibel-Palade bodies of endothelial cells)
What does vitamin K deficiency result in?
disrupts function of multiple coag factors
vit K is essential for gamma carboxylating factors
How does coumadin work?
blockes epoxide reductase
Who is prone to vitamin K deficiency?
2) long term antibiotic therapy
What are 3 reasons why liver failure can lead to bleeding problems?
1) decreased production of coag factors
2) decreased activation of vitamin K by epoxide reductase