17: Clotting Cascade

Question 1

What triggers extrinsic and intrinsic pathways of clotting cascade?

Answer 1

Extrinsic: external trauma, causing blood to escape vascular system
Intrinsic: internal trauma in vascular system

Question 2

Which path is quicker in clotting cascade?

Answer 2

Extrinsic

Question 3

Four things that activate intrinsic pathway?

Answer 3

Platelets, exposed endothelium, chemicals, collagen

Question 4

What factor is thrombin?

Answer 4

Factor II

Question 5

Hemostasis: primary and secondary

Answer 5

1. Primary: platelets in blood aggregate at injury site -> platelet plug to block hole
2. Secondary: platelet plug further reinforced by fibrin mesh produced through proteolytic coagulation cascade

Question 6

Components of primary hemostasis

Answer 6

Platelets, glycoproteins, collagen, vWf, fibrinogen

Question 7

Components of secondary hemostasis

Answer 7

Subendothelial collagen, thromboplastin, coagulation factors, fibrinogen, fibrin

Question 8

Thrombin converts what?

Answer 8

Fibrinogen -> fibrin

Question 9

What four things are activated by thrombin?

Answer 9

Factor XIII, V, VIII, platelets

Question 10

Where does the vitamin K formation cycle occur?

Answer 10

Liver

Question 11

Six factors formed by y-glutamyl-carboxylase

Answer 11

2, 7, 9, 10, C, S

Question 12

How do oral anticoagulants work?

Answer 12

Vitamin K inhibition

Question 13

Why is full effect of Warfarin not seen for about 48 hours?

Answer 13

Previously activated factors in blood must decline + re-synthesis must begin before warfarin will interfere

Question 14

Peak plasma concentration of warfarin

Answer 14

3hrs after admin

Question 15

Two forms or warfarin and what they are bound to?

Answer 15

S-warfarin: albumin

R-warfarin: proteins

Question 16

Which type of warfarin is 5x more potent

Answer 16

S-warfarin

Question 17

Major food interaction with warfarin

Answer 17

Green leafy veggies

Question 18

Four drug classes that interact with warfarin

Answer 18

1. Those metabolized by CYP2C9
2. NSAIDs
3. Tylenol
4. Many prescription meds

Question 19

Counseling points for starting Warfarin

Answer 19

1. Check with dr or pharmacist before starting new drug
2. Routine INR must be done
3. Watch for S/S of bleeding
4. Side effects: stomach pain, palpitations, fever, wheezing, N/V/D
5. Carry an ID card
6. Be careful of diet

Question 20

What risk is significantly increased with Protein C deficiency?

Answer 20

Risk of DVT

Question 21

Which factor is deficient in hemophilia A and B

Answer 21

A: factor VIII
B: factor IX

Question 22

Other names for hemophilia A and B

Answer 22

A: Classic hemophilia
B: Christmas disease

Question 23

Which type of hemophilia is 4x as common as the other?

Answer 23

Hemophilia A is more common