Venous Thrombosis

Question 1

Arterial thrombosis treatment

Answer 1

Aspirin and other anti-platelet drugs

Question 2

Virchow’s triad =

Answer 2

1. Stasis
2. Vessel wall (valvular damage)*
3. Hypercoagulability

*DVT damages valves, increasing future risk

Question 3

Venous thrombosis treatment

Answer 3

Heparin/warfarin/new oral anticoagulants

Question 4

Diagnostic test for DVT =

Answer 4

US Doppler leg scan

Question 5

Patient unlikely to have DVT based on Wells score - what test is used to rule out DVT ?

Answer 5

D-dimers

Question 6

Scoring system for DVT ?

Answer 6

Wells score

Question 7

PE signs and symptoms ?

Answer 7

• Dyspnoea - often acute onset
• Pleuritic chest pain
• Symptoms of DVT - leg pain, swelling etc.
• Collapse (/sudden death)
• Fever
• Haemoptysis
• Tachycardia
• Hypoxia
• Cyanosis
• Low BP

Question 8

4 components of a normal haemostatic system ?

Answer 8

1. Formation of platelet plug
   - Primary Haemostasis
2. Formation of fibrin clot
   - Secondary Haemostasis
3. Fibrinolysis
4. Anticoagulant defences

Question 9

Wells score indicates PE is likely - what investigation ?

Answer 9

CT Pulmonary angiogram

Question 10

Wells score indicates PE is unlikely - what investigation ?

Answer 10

D-dimer

If D-dimer is positive, perform a CT pulmonary angiogram

Question 11

CT Pulmonary angiogram is contraindicated in which conditions ?

Answer 11

Renal impairment, contrast allergy or at risk from radiation (pregnancy)

Question 12

What scan is used when CTPA is contraindicated ?

Answer 12

V/Q scan

Question 13

X-ray sign for PE ?

Answer 13

Wedge-shaped infarct

Question 14

Mutations in hereditary thrombophilias ?

Answer 14

• Factor V Leiden
• Prothrombin 20210 mutation
• Antithrombin deficiency
• Protein C deficiency
• Protein S deficiency

Question 15

When to consider hereditary thrombophilia screening?

Answer 15

• Venous thrombosis <45 years old
• Recurrent venous thrombosis
• Unusual venous thrombosis
• Family history of venous thrombosis
• Family history of thrombophilia

Question 17

Short-term prophylaxis used prior to operations ?

Answer 17

LWMH

Question 18

Features of Antiphospholipid antibody syndrome

Answer 18

Recurrent thromboses
- arterial inc. TIAs
- venous

Recurrent foetal loss

Mild thrombocytopaenia

Question 19

Pathogenesis of antiphospholipid antibodies

Answer 19

Antibodies change B2 glycoprotein 1

This leads to activation of primary and secondary haemostasis and vessel wall abnormalities

They also have specificity for anionic phospholipids and prolong phospholipid-dependant coagulation tests in vitro

Therefore, they’re also known as Lupus anticoagulants

Question 20

Treatment of antiphospholipid syndrome arterial/venous thrombosis ?

Answer 20

Arterial - aspirin
Venous - warfarin

Question 21

Causes of multiple clotting factor deficiency

Answer 21

Liver disease
Vitamin K deficiency
DIC

Question 22

Vitamin K clotting factors

Answer 22

II, VII, IX, X

*common exam question

Question 23

Reasons for Vitamin k deficiency

Answer 23

Malabsorption - Crohn’s etc
Biliary obstruction - Gallstones, malignancy

Question 24

Warfarin MOA

Answer 24

Vitamin K antagonist

Interferes with clotting factors 2,7,9,10

Question 25

Where are platelets formed?

Answer 25

Bone marrow

Question 26

Does liver disease cause low platelets?

Answer 26

Yes

Question 27

Does DIC cause low platelets

Answer 27

Yes

Question 28

Does Vitamin K deficiency cause low platelets?

Answer 28

No

Question 29

Best liver test to check liver synthesis ?

Answer 29

Albumin