Thrombosis

Question 1

Describe the process of protein C and protein S in stopping hemostasis

Answer 1

They inhibit factor V and VIII to stop clotting

Question 2

Describe the antithrombin in stopping hemostasis

Answer 2

• made in liver & circulates in blood
• binds to thrombin to stop clotting

Question 3

What happens if we have too much hemostasis

Answer 3

arterial thrombosis: stroke, heart attack

venous thrombosis: DVT, PE

Question 4

What are the thrombotic mechanisms and risk factors associated with arterial clotting

Answer 4

• underlying vascular disease
• excess platelet activation

Question 5

What are the thrombotic mechanisms and risk factors associated with venous clotting

Answer 5

• stasis
• failure to regulate thrombin generation

Question 6

Describe the difference between arterial and venous clots

Answer 6

Arterial: primarily platelets with a little bit of fibrin

Venous: primarily fibrin with a little bit of platelets

Question 7

Describe the difference in treatment between arterial and venous clotting

Answer 7

Arterial: RF mods & antiplatelet drugs (ASA)

Venous: prophylaxis, blood thinners

Question 8

What things can cause both arterial and venous thrombosis

Answer 8

• antiphospholipid antibodies
• myeloproliferative disorders
• heparin induced thrombocytopenia

Question 9

Describe superficial thrombophlebitis

Answer 9

inflammation of superficial veins (tributaries of great saph)

Question 10

What are the 5 major thrombophilias

Answer 10

Traditional (multiple mutations, rare, strong)
- antithrombin deficiency
- protein C deficiency
- protein S deficiency

Modern (point mutations, common, weak)
- factor V Leiden
- prothrombin gene mutation

Question 11

Which thrombophilias have a failure to control thrombin generation

Answer 11

• factor V leiden
• prothrombin gene mutation
• protein C & S deficiency

Question 12

Describe the pathophysiology of factor V leiden

Answer 12

Point mutation in factor V gene at critical site involved in binding of fV to APC (protein C)

Question 13

List some acquired triggers for thrombosis

Answer 13

• immobilization
• surgery
• trauma
• pregnancy/post partum
• estrogens
• age

Question 14

Which genetic thrombophilias are generally weaker/asymptomatic

Answer 14

Question 15

Which genetic thrombophilias are generally stronger/more symptomatic

Answer 15

Question 16

When to work up someone for thrombophilia

Answer 16

• strong family hx of thrombosis
• recurrent thrombosis
• unusual clinical presentation (young, unprovoked, unusual location)

Question 17

How long to treat a provoked clot

Answer 17

3-6 mos if no other genetic/fam hx

12 mos if… extensive clot burden, life-threatening provoked clot, persisting reversible risk factor

Question 18

How long to treat an unprovoked clot

Answer 18

lifelong anticoagulation