Clinical Haemostasis and Thrombosis 12

Question 1

How would you describe normal haemostasis?

Answer 1

An equilibrium between coagulation factors/platelets and fibrinolytic factors/anticoagulant proteins

Question 2

What are the characteristics of abnormal bleeding?

Answer 2

• spontaneous
• prolonged bleeding
• restarts after stopping
• abnormal proportion relating to injury/trauma

Question 3

What defects can affect primary haemostasis (primary plug formation)?

Answer 3

• collagen (vessel wall)
• Von willebrand factor
• platelets

Question 4

What in indicative of thrombocytopenia?

Answer 4

Petechiae

Question 5

What does secondary heamostasis involve?

Answer 5

The stabilisation of the plug by formation of thrombin from prothrombin to form fibrin from fibronogen

Question 6

What is haemophilia?

Answer 6

Failure to generate fibrin to stabilize the plug as Factor 8 is missing so there is no immediate increase in thrombin

Question 7

What are some common defects of secondary haemostasis?

Answer 7

• haemophilia (factor 8 or 9)
• Liver Disease
• Drugs (e.g. Warfarin)
• Dilution
• Consumption (dissemnated intravascular coagulation

Question 8

Describe disseminated intravascular coagulation:

Answer 8

• Generalised activation of tissue factor in the blood when it doesnt need to be
• associated with sepsis, major tissue damage and infammation
• activation of fibrinolysis depletes fibrinogen

Question 9

What are the consequences of disseminated intravascular coagulation?

Answer 9

Widespread bleeding internally and IV lines. Deposition of fibrin in vessels causing organ failure

Question 10

What is a hallmark of haemophilia?

Answer 10

Haemathrosis (bleeding in joints)

Question 11

What are defects of clot stability?

Answer 11

1) Excess fibrinolytic (tPA, plasma)
2) Deficient Antifibrinolytic
3) Anticoagulant Excess (usually due to therapeutic administration)

Question 12

What are the effects of thrombosis?

Answer 12

• obstructed blood flow

- embolism

Question 13

Define embolism

Answer 13

movement of substance from one part of circulation to another

Question 14

What are the consequences of a thrombo-embolism?

Answer 14

• Death
• Recurrence
• Thrombophlebitic syndrome (swelling and ulcers in the legs due to damage of valves leading to stasis)
• Pulmonary hypertension (circulation of lungs never returns to levels pre - thrombo-embolism)

Question 15

What is Virchows Triad?

Answer 15

Three causative factors of thrombosis:

1) Blood
2) Vessel Wall
3) Flow

Question 16

What blood factors cause increased thrombosis risk?

Answer 16

• Deficiency of anticoagulant proteins (antithrombin, Protein C , Protein S0
• Increased coagulant proteins ( factor 8, 2 and 5 leiden)
• Thrombocytosis

Question 17

What vessel wall factors increase thrombosis risk?

Answer 17

• Proteins such as thrombomodulin, tissue factor and tissue factor inhibition pathway and varying expression of these proteins

Question 18

What is the treatment for thrombosis?

Answer 18

• lyse clot via tPA
• Reduce recurrence via increased anticoagulant factor (heparin), decrease coagulant factors (heparin) and inhibit procoagulant factors