Secondary Hemostasis

Question 1

_______ binds the platelet to VWF while _________ binds platelets to platelets (allowing aggregation)

Answer 1

Gp1b

GpIIb/IIIa

Question 2

What is the end product of the coagulation cascade

Answer 2

thrombin

Question 3

what does thrombin do?

Answer 3

convert fibrinogen to fibrin

Question 4

What does fibrin do?

Answer 4

stabilize

Question 5

Where are the factors of the coagulation cascade produced?

Answer 5

the liver

Question 6

What 3 things do coagulation factors require for activation?

Answer 6

1) exposure to activating substance
2) phopholipid surface
3) calcium (derived from platelets)

Question 7

What is the cause of secondary hemostasis?

Answer 7

factor abnormalities

Question 8

What are the clinical features of secondary hemostasis disorders?

Answer 8

deep bleeding (into muscles and joints)

Question 9

What does PT measure?

Answer 9

extrinsic and common pathway

Question 10

What does PTT measure?

Answer 10

intrinsic and common pathways

intrinsic has more factors involved, measured by the test with more letters

Question 11

The goal of the coagulation cascade is to produce __________

Answer 11

factor 10 (the perfect 10)

Question 12

What activates factor 12?

Answer 12

subendothelial collagen

Question 13

What activates factor 7?

Answer 13

tissue thromboplastin

Question 14

What initiates the extrinsic pathway?

Answer 14

factor 7

Question 15

What test is a better measurement for the heparin effect?

Answer 15

PTT

Question 16

What test is a better measurement for coumadin effect?

Answer 16

PT

Question 17

What is the cause of hemophilia A?

Answer 17

genetic deficiency in factor 8 (aaaaate)

X-linked recessive (can get de novo mutations)

Question 18

What are the signs and symptoms of patients with disorders of secondary hemostasis?

Answer 18

deep tissue, joint, and postsurgical bleeding

Question 19

What are the lab findings for disorders of secondary hemostasis?

Answer 19

1) HIGH PTT, normal PT
2) LOW factor 8
3) normal platelet count and bleeding time

Question 20

What is the treatment for hemophilia A?

Answer 20

recombinant factor 8

Question 21

What is the cause of hemophilia B?

Answer 21

factor 9 deficiency

Question 22

How does hemophilia B look clinically?

Answer 22

the same as A! (both affect intrinsic pathway)

Question 23

What is the most common coag factor inhibitor?

Answer 23

anti-factor 8

resembles hemophila A

Question 24

how do you determine the difference between hemophilia A or coag factor inhibitor disease?

Answer 24

mixing study

Question 25

What is a mixing study?

Answer 25

mix normal plasma with patient plasma

Question 26

What would the mixing study look like for hemophilia A?

Answer 26

can regain coagulation

Question 27

What does mixing study look like for coag factor inhibitor?

Answer 27

FAILS, antibody will hit normal plasma too and it won’t bind (cannot correct PTT)

Question 28

What is Von Willebrand’s Disease?

Answer 28

defect in VWF (MOST COMMON INHERITED COAG DISORDER)

autosomal dominant

Question 29

What do lab findings look like for VWF disease?

Answer 29

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

Question 30

What is the treatment of VWF disease?

Answer 30

desmopressin (increases release of VWF from Weibel-Palade bodies of endothelial cells)

Question 31

What does vitamin K deficiency result in?

Answer 31

disrupts function of multiple coag factors

vit K is essential for gamma carboxylating factors

Question 32

How does coumadin work?

Answer 32

blockes epoxide reductase

Question 33

Who is prone to vitamin K deficiency?

Answer 33

1) newborns
2) long term antibiotic therapy
3) malabsorption

Question 34

What are 3 reasons why liver failure can lead to bleeding problems?

Answer 34

1) decreased production of coag factors

2) decreased activation of vitamin K by epoxide reductase

Question 35

Why can large volume transfusions lead to bleeding problems?

Answer 35

dilutes coag factors (relative deficiency)