Coagulation

Question 1

What changes in coagulation do you see with cirrhosis?

Answer 1

Increase PT/PTT b/c it can’t make the coagulation factors as well. Also can’t make Protein C & S

Question 2

What are the things that factor 12a converts?

Answer 2

11-11a (pro-clot forming)

prekallikrein–>kallikrein (anti-clot forming)

Question 3

Describe what happens once you get kallikrein?

Answer 3

you get conversion of plasminogen–>plasmin (clot buster of fibrin mesh)
and you convert HMWK–>bradykinin

Question 4

What are the functions of bradykinin?

Answer 4

1. increase vascular permeability
2. vasodilation
3. pain

Question 5

What are some factors that are important for coagulation?

Answer 5

phospholipids
Ca++

**give anti-Ca++ stuff for bags of blood to prevent clotting

Question 6

What types of bonds are seen in the fibrin mesh?

Answer 6

covalent bonds

Question 7

What do streptokinase and tpA do?

Answer 7

increase conversion of plasminogen to plasmin

Question 8

What does aminocaproic acid do?

Answer 8

inhibits conversion to plasmin

Question 9

What is heparin’s MOA?

Answer 9

it stimulates anti-thrombin. which acts on factor 2a

Question 10

What are the accelerating factors of the coagulation cascade? What inhibits them?

Answer 10

8a, 5a

inhibited by Proteins C&S

Question 11

What is the rate-limiting step of the coag cascade?

Answer 11

10–>10a

Question 12

What does s. aureus do to coag cascade?

Answer 12

its coagulase enzyme converts fibrinogen–>fibrin

Question 13

What does PT test?

Answer 13

add tissue factor
tests extrinsic and common pathways
7, 10, 5, 2

should be roughly 10-13s

Question 14

What is the purpose of the INR?

Answer 14

international normalized ratio
INR=1 is normal
INR>1 long time to clot! Deficiency of a factor somewhere perhaps

Question 15

What does the PTT test tell?

Answer 15

add phospholipid and silica
tests internal pathway and common pathway
12, 11, 9, 8, 10, 5, 2

should be 25-40s

Question 16

What is bleeding time?

Answer 16

cut a pt and see how long they bleed, should be 2-9 minutes

measure of platelet function, NOT coag cascade

Question 17

hemophilia A, B, C are deficiencies of which factors? What do they do to PT/PTT?

Answer 17

A-8. X-linked recessive
B-9 X-linked recessive
C-11 autosomal recessive
increase PTT, not PT

Question 18

What’s the deal with Vit K deficiency?

Answer 18

decrease in Proteins C, S, 2, 7, 9, 10
bleeding time normal
PT and PTT increased

Question 19

Which patients do you see VIt K deficiency in?

Answer 19

Newborns–don’t have gut flora to make
Warfarin (too much)
End stage liver dx–can’t make clotting factors and proteins

Question 20

What’s the deal with antithrombin deficiency?

Answer 20

Heparin has little effect on PTT
Can be genetic or from nephrotic syndrome and loss of antithrombin in urine
not really abnormal PT, PTT otherwise
Hypercoagulable

Question 21

What’s the deal with Factor V Leiden?

Answer 21

Protein C can’t inhibit this V

hypercoagulable

Question 22

What’s the deal with Protein C or S deficiency?

Answer 22

can’t inhibit 5a, 8a

after warfarin admin, sometimes get skin and subcu tissue necrosis

Question 23

What’s the deal with Prothrombin Gene mutation?

Answer 23

G20210A. Guanine–>Adenine. think 90210
mutation in 3’ untranslated region
increased production of prothrombin.
hypercoagulable