4.2 - Secondary hemostasis and related disorders

Question 1

where does the calcium required for coagulation cascade activation come from?

Answer 1

platelet dense granules

Question 2

hemophilia A is due to a defective in factor ___ and the inheritance is ____

Answer 2

8, XR

Question 3

hemophilia B is due to a defective factor ___ and the inheritance is ____

Answer 3

9, XR

Question 4

if PTT does not correct upon mixing normal plasma with patient’s serum (mixing study), what should you consider?

Answer 4

coagulation factor inhibitor - acquired autoantibody against a coagulation factor (usually 8)

Question 5

how can coagulation factor inhibitor be differentiated from hemophilia A?

Answer 5

mixing study - PTT DOES correct in hemophilia A, when mixing normal plasma with patient’s serum

Question 6

what are the lab findings in vWF disease?

• bleeding time
• PTT
• ristocetin

Answer 6

• increased bleeding
• increased PTT
• abnormal ristocetin

Question 7

what is the treatment for vWF disease? why?

Answer 7

• desmopression, which increases vWF release from weibel palade bodies of endothelial cells (vWF helps stabilize factor 8)

Question 8

what is the relationship of vWF to factor 8?

Answer 8

vWF helps stabilize factor 8

Question 9

vitamin K is activated by _________ in the liver

Answer 9

epoxide reductase

Question 10

activated vitamin K carboxylates which factors?

Answer 10

2, 7, 9, 10, C, S

Question 11

the effect of liver failure on coagulation is followed via what test?

Answer 11

PT