Thrombosis and Embolism (haematology)

Question 1

What are the three natural anticoagulants we have?

Answer 1

Antithrombin
Protein C system
Tissue factor pathway inhibitor (TFPI)

Question 2

What are the causes of thrombosis?

Answer 2

-Stasis
-Vessel wall injury
-Hypercoagulability

Question 3

What type of clot forms in:
1. Veins
2. Arteries

Answer 3

1. Red clot (rich in fibrin and trapped RBCs.)
2. White clot (rich in platelets)

Question 4

What substance is used to treat deep vein clotting?

Answer 4

Warfarin

Question 5

How do we treat the two types of clots?

Answer 5

1. Venous clot- treatment is medication that interrupts with the coagulation cascade, such as warfarin.
2. Arterial clot- treatment is drugs that block platelet activation.

Question 6

What are the risk factors for arterial thrombosis? (7)

Answer 6

-Elevated factor VIII
-Elevated fibrinogen levels
-Lupus anticoagulant
-Polycythaemia rubra vera
-Essential thrombocythaemia
-Diabetes, hypertension
-Smoking

Question 7

What are the causes of venous thrombosis? (3)

Answer 7

•Thrombophilia (easy formation of blood clots)
•Vessel wall injury (causes plaque formation and plaque rupture)
•Reduced flow (immobility, obesity/pregnancy, limb paralysis, long distance travel).

Question 8

What are the causes of:
1. Acquired thrombophilia
2. Inherited thrombophilia

Answer 8

1. Pregnancy, contraceptive pill, malignancy, lupus anticoagulant.
2. Factor V leiden, protein C deficiency, protein S deficiency, prothrombin mutation, antithrombin deficiency.

Question 9

What are the clinical presentations of thrombosis? (2)

Answer 9

Arterial thrombosis- ischaemia (e.g MI)
Venous theombosis- stasis and blockage (e.g deep vein thrombosis)

Question 10

Treatment for:
1. Arterial thrombosis (5)
2. Venous thrombosis (3)

Answer 10

1. Fibrinolysis, streptokinase, urokinase, TPA as well as antiplatelet therapy.
2. Warfarin, heparin, and new anticoagulants.

Question 11

Which coagulation factors does warfarin inhibit?

Answer 11

Vitamin K dependent, II, VII, IX and X.

Question 12

Which coagulation factors does heparin inhibit?

Answer 12

• factor II and X.

Question 13

What is the mechanism of action for warfarin? (3)

Answer 13

Warfarin inhibits the enzyme responsible for the activation of vitamin K.
-Inhibits the activation of vitamin K dependent factors (II, VII, , IX and X) and protein C, S.
-Decreases coagulation.

Question 14

What are the indications of warfarin:
1. Good evidence
2. Limited evidence

Answer 14

1. Embolic stroke, DVT, atrial fibrillations.
2. Congestive heart failure, dilated cardiomyopathy, non-embolic stroke, peripheral vascular diseases.

Question 15

What major risk is associated with using warfarin especially in the elderly?

Answer 15

Risk of bleeding

Question 16

What are the indications of heparin? (5)

Answer 16

-Acute venous thrombosis
-Acute artery occlusion
-Pregnancy
-Catheters and lines
-Prophylaxis

Question 17

Side effects of heparin (3)

Answer 17

-Bleeding
-Heparin-induced thrombocytopenia
-Osteoporosis

Question 18

Which products are used to reverse warfarin? (3)

Answer 18

-Prothrombin concentrate, fresh frozen plasma, vitamin k.

Question 19

Which substance is used to reverse heparin?

Answer 19

Protamine sulphate

Question 20

What is the difference between embolism and thrombosis?

Answer 20

Thrombosis is easy formation of a blood clot, embolism is when the blood clot travels in the blood vessels (thrombosis can lead to embolism).

Question 21

Risk factors for embolism (5)

Answer 21

-Obesity, immobility
-Smoking
-Pregnancy
-Elderly >65
-Diabetes , hypertension

Question 22

Different types of embolism

Answer 22

-Cerebro-vascular accident
-Air embolism
-Pulmonary embolism
-Amniotic fluid embolism