Secondary Hemostasis

Question 1

Expression of which cofactors initiates coagulation?

Answer 1

Tissue factor (III)

Question 2

Which coagulation factor drives amplification?

Answer 2

Thrombin (IIa)

Question 3

What are the 4 VitK dependent coagulation factors?

Answer 3

2, 7, 10, 9.. coagulation time!

Question 4

What factor increases antithrombin activity?

Answer 4

Heparin

Increase activity by 1000x

Question 5

Where is heparin found in the body?

Answer 5

Expressed on endothelial cells and circulates in the plasma

Question 6

If you have a protein losing enteropathy, are you hypo or hyper -coagulable?

Answer 6

Hypercoaguable –> loss of antithrombin

Question 7

What are the two major end products of fibrinolysis ?

Answer 7

Fibrin degradation products (FDP)

D-dimers

Question 8

When are fibrin degradation products and D-dimers increased??

Answer 8

When there is increased clotting—> increased clot breakdown

Question 9

What is responsible for clot degradation

Answer 9

Plasmin

Question 10

To run coagulation tests, how should blood be collected?

Answer 10

“Clean stick”

Avoid taking blood from heparinized catheter

Question 11

Blood for coagulation tests should be collected in ??

Answer 11

Sodium citrate tube (blue top) –> calcium chelator

Question 12

What two tests can be used to measure the intrinsic pathway?

Answer 12

Activated partial prothrombin time (PPT)

Activated clotting time (ACT)

Question 13

What test is more sensitive for measuring the intrinsic pathway of coagulation?

Answer 13

Activated prothrombin time (70% factor deficiency to produce result)

–>ACT requires a 95% deficiency to produce a result

Question 14

What test can be used to measure the extrinsic pathway?

Answer 14

Prothrombin time (PT)

Question 15

What test is good to detect a vitamin k deficiency due to the short half life of its coagulation factors

Answer 15

PT -> extrinsic pathway (factor VII)

Question 16

If you have a prolonged PT, what are your two differentials?

Answer 16

Factor VII deficiency

Common pathway deficiency

Question 17

If you have a prolonged PTT, but a normal PT, what can you infer from these results?

Answer 17

Deficiency in factors 12, 11, 9, or 8 (intrinsic pathway)

Question 18

If you have a normal PPT and and prolonged PT, what can you infer from these results?

Answer 18

Deficiency in factor VII

Question 19

If PTT is prolonged and PT is prolonged, what can you infer?

Answer 19

Deficiency in factors of the common pathway

Question 20

If there is an increase in FDP or D-dimers, what is the cause?

Answer 20

Increased fibrinolysis
Severe internal hemorrhage
Decreased FDP clearance by the liver

Question 21

What toxin is commonly associated with vitK deficiency

Answer 21

Warfarin

Question 22

What bleeding pattern do you expect in an animal with vitK deficiency?

Answer 22

Increase bleeding

• anemia, weakness
• hypovolemia
• dyspnea
• lameness
• neurological

Question 23

RBC: anemic (regenerative) 
PLT: normal 
MPV: normal 
PTT/ACT: prolonged 
PT: prolonged

Answer 23

Vitamin K coagulopathy

Question 24

What are common causes of DIC?

Answer 24

Induction of tissue factor -sepsis, tissue necrosis, neoplasia

Endothelial damage - exposed collagen

Proteolytic enzyme -snake venom or pancreatitis

Question 25

What are the two phases of DIC?

Answer 25

Hypercoaguable phase (thrombosis and ischemic necrosis) Consumptive phase (bleed)

Question 26

What phase of DIC results in bleeding?

Answer 26

Consumptive phase

Question 27

What bleeding pattern is seen in DIC?

Answer 27

Mucosal due to PLT consumption | Hemorrhage due to factor consumption

Question 28

What is the cardinal change seen in DIC?

Answer 28

Thrombocytopenia

Question 29

Thrombocytopenia Prolonged PTT/PT Increased FDP and D-dimers Decreased antithrombin Hemorrhagic anemia Schistocytes What dis?

Answer 29

DIC

Question 30

Why are coagulopathies associated with liver disease?

Answer 30

Decreased production of coagulation factors and/or Production of dysfunctional platelets

Question 31

What is the classic presentation of an inherited factor deficiency?

Answer 31

Young animal with bleeding disorder

Question 32

What are the three most common inherited factor deficiencies?

Answer 32

Hemophilia A Hemophilia B Factor XII (Hageman's disease )

Question 33

What common inherited factor deficiencies are associated with bleeding

Answer 33

Hemophilia A: VII | Hemophilia B: IX

Question 34

PLT: normal BMMT: normal PTT/ACT: prolonged PT: normal

Answer 34

Inherited factor deficiency