Thrombosis and Risk Factors

Question 1

Risk factors for thrombosis

Answer 1

Virchow’s triad- flow, composition or vessel wall

Question 2

Outline the brief pathology of arterial thrombosis

Answer 2

Atherosclerosis, rupture of atheromatous plaque, endothelial injury, platelet aggregation

Question 3

Describe the composition of thrombi in venous thrombosis

Answer 3

Pred. fibrin and RBCs, less platelets

Question 4

Complication of venous thrombosis

Answer 4

Venous thromboembolism (VTE)

Question 5

Treatment for VTE

Answer 5

Low molecular weight heparin e.g. fondaparinux
Newer anticoagulants e.g:
Xa inhibitors rivaroxaban
IIa inhibitors dabigatran
Compression stockings

Question 6

Natural procoagulants

Answer 6

Clotting factors

Question 7

Natural anticoagulants

Answer 7

Antithrombin III
Proteins C+S
Fibrinolytics

Question 8

How does heparin work?

Answer 8

Increases antithrombin activity

Question 9

Does LMWH predominantly target Xa or IIa?

Answer 9

Xa

Question 10

Does fondaparinoux predominantly target Xa or IIa?

Answer 10

entirely Xa

Question 11

Diagnostic test for VTE

Answer 11

Wells score
D-dimer test
Ultrasound
VQ scan

Question 12

What test is used to measure the breakdown products of fibrin clots- specific to plasmin acting on fibrin

Answer 12

D-dimer

Question 13

What does the VQ scan pick up in PE?

Answer 13

Ventilation:perfusion mismatch

Question 14

What are the advantages of novel anticoagulants?

Answer 14

Dose is uniform for post patients and rapid onset

Question 15

Target INR

Answer 15

2.5

Question 16

Familial or acquired disorder of the haemostatic mechanism likely to predispose to thrombosis

Answer 16

Thrombophilias

Question 17

Heritable thrombophilias

Answer 17

Antithrombin def
Protein C def
Protein S def
FV leiden-activated protein C resistance
Prothrombin 20210A
Dysfibrinogenaemia

Question 18

Prothrombin 20210A

Answer 18

Too much prothrombin

Question 19

An example of an acquired thrombophilia

Answer 19

Antiphospholipid syndrome- autoimmune, hypercoagulable state

Question 20

Clinical features of thrombophilia

Answer 20

VTE
Superfical thrombophlebitis
Thrombosis of cerebral, axillary, portal and mesenteric veins
Coumarin induced skin necrosis (PC deficiency)
Obstetic complications- fetal wastage- thrombosis of placental circulation

Question 21

What is the function of protein C

Answer 21

Breaksdown Va and VIIIa

Question 22

What is the function of protein S

Answer 22

Cofactor for protein C

Question 23

Describe factor V leiden

Answer 23

Va resistant to protein C

Question 24

Examples of hypercoagulable state

Answer 24

FV leiden
Pill
Pregnancy
Immobility