Week 3- venous thrombosis

Question 1

Describe an arterial thrombosis?

Answer 1

Its a platelet rich atherosclerotic plaque. The vessel wall is injured, LDL cholesterol builds up in it. Platelets adhere to it.

Question 2

How do you treat arterial thrombosis?

Answer 2

Aspirin and other anti-platelet drugs

Modify risk factors for atherosclerosis.

Question 3

Describe a venous thrombosis?

Answer 3

Platelets are not activated in this type of clot. Its a fibrin rich clot due to activation of the coagulation cascade.

Question 4

What makes up virchows triad?

Answer 4

Stasis

Hypercoagulability

Vessel wall (endothelial) damage

Question 5

What is the treatment for venous clots?

Answer 5

Heparin/warfarin and newer oral anticoagulants.

Question 6

Why does valvular failure cause blood clots?

Answer 6

Valvular failure leads to blood pooling, which leads to stasis which leads to blood clotting.

Question 7

Name some examples of patients in hypercoagulable states?

Answer 7

Hypercoagulable = high levels of clotting factors in the blood.

Oral contraceptive pill, pregnancy, high oestrogen states.

Question 8

Symptoms of a DVT

Answer 8

Limb is swollen, hot and tender.

Pitting oedema

Question 9

Symptoms of a pulmonary embolism

Answer 9

Sharp stabbing pain (pleura rub together its incredibly sore)

Hypoxic

Heart cant pump the blood to the lungs,

Pulmonary infarction causes this.

Question 10

Risk factors for VTE

Answer 10

Old age

Obesity

Pregnancy

Peurperium

Oestrogen therapy

Previous DVT/PE

Trauma/surgery

Malignancy

Paralysis

Infection

Thrombophillia

Question 11

Which of the risk factors cause stasis?

Answer 11

Age

Marked obesity

Pregnancy

Previous DVT/PE

Trauma/surgery

Malignancy

Paralysis

Question 12

Which of the risk factors cause vessel damage?

Answer 12

Age

Previous DVT/PE

Question 13

Which of the risk factors cause hypercoagulability?

Answer 13

Age

Pregnancy

Peurperium

Oestrogen therapy

Trauma/surgery

Malignancy

Infection

Thrombophillia

Question 14

What is hypercoagulability associated with?

Answer 14

Release of tissue factor, raised VWF and factor VIII.

Question 15

What is thrombophillia?

Answer 15

Familial or acquired disorders of the haemostatic mechanism which are likely to predispose to thrombosis.

Question 16

What can thrombophillia be due too?

Answer 16

Can be due to the lack of naturally occuring anticoagulants e.g. antithrombin or protein c and protein s.

Question 17

What sort of clots are thrombophillia sufferers likely to have?

Answer 17

Venous thrombosis.

Question 18

What is factor V leiden?

Answer 18

Factor V works completely normally however doesnt respond to switching off from Protein C and Protein S.

Question 19

Describe hereditary thrombophillias?

Answer 19

A group of genetic defects in which affected individuals have an increased tendancy to develop premature, unsual and recurrent thrombosis.

Question 20

Give examples of hereditary thrombophillias?

Answer 20

Factor V Leiden

Prothrombin 20210 mutation

Antithrombin deficiency

Protein C deficiency

Protein S deficiency

Question 21

When should you consider screening for hereditary thrombophillias?

Answer 21

Venous thrombosis<45 years old

Recurrent venous thrombosis

Unusual venous thrombosis (cerebral veins or upper limb)

Family history of venous thrombosis

Family history of thrombophillia

Question 22

How do you manage hereditary thrombophillias?

Answer 22

Advice on avoiding risk

Short term prophylaxis- to prevent thrombotic events during periods of known risk

Short term anticoagulation- to treat thrombotic events

Long term anticoagulation- if recurrent thrombotic events occur.

Question 23

This explains how risk factors can affect the risk of thrombosis.

Question 24

What is the toss up with long term anticoagulation?

Answer 24

Risk of recurrent thrombosis vs risk of serious haemorrhage.

Question 25

What is more important, the clinical history or the results of thrombophillia screening?

Answer 25

Clinical history is much more important- need to pay attention to:

• History of previous thrombosis
• Spontaneous thrombosis rather than acquired transient RF e.g. immobility due to surgery
• Family history
• Thromobphillia screening results.

Question 26

Name an acquired thrombophillia?

Is it more or less likely to cause thrombosis than the hereditary ones?

Answer 26

Antiphospholipid syndrome

More likely to cause thrombosis.

Question 27

What are the features of antiphospholipid syndrome?

Answer 27

Recurrent thromboses (both arterial and venous- could be Hx of TIAs. This is due to it activating both primary and secondary haemostasis)

Recurrent fetal loss

Mild thrombocytopenia

Question 28

Describe the pathogenesis of antiphospholipid syndrome?

Answer 28

Antibodies lead to a conformational change in beta 2 glycoprotein 1 (a protein with unknown function in health) which leads to activation of both primary and secondary haemostasis and vessel wall abnormalities.

Question 29

Describe the antibodies in antiphospholipid syndrome?

Answer 29

They are autoantibodies with a specificity for anionic phospholipids and which prolong phospholipid dependent coagulation tests in vitro

Also called lupus anticoagulants.

Question 30

What conditions are associated with antiphospholipid syndrome?

Answer 30

Autoimmune disorders

Lymphoproliferative disorders

Viral infections

Drugs

Primary

Question 31

How do you treat anti-phospholipid syndrome?

Answer 31

It depends on how its presented, if venous thrombosis give warfarin, if arterial give aspirin. if both, give both.