Haematology 8 - Thrombosis: aetiology and management

Question 1

What is the triad of symptoms in thrombophlebitic syndrome?

Answer 1

Recurrent pain
Swelling
Ulcers

Question 2

What catalyses the conversion of fibrinogen to fibrin?

Answer 2

Thrombin

Question 3

Which anticoagulant molecules are expressed on the blood vessel wall?

Answer 3

Thrombomodulin
Endothelial Protein C receptor
TFPI

Question 4

How does inflammation affect the blood vessel wall?

Answer 4

It makes it prothrombotic

Question 5

Recall 5 effects of inflammation on the blood vessel wall

Answer 5

1. Anticoagulant molecules are downregulated
2. TF expressed
3. Prostacyclin decreased
4. Adhesion molecules upregulated
5. VWF released (leading to neutrophil capture, and formation of NETs)

Question 6

How do neutrophils contribute to immunothrombosis?

Answer 6

Neutrophils release DNA, which is procoagulant

Question 7

What is the mechanism of action of clopidogrel?

Answer 7

Inhibits ADP receptors

Question 8

Give 4 ways in which blood stasis promotes thrombosis

Answer 8

1. Accumulation of activated factors
2. Promotes platelet adhesion
3. Promotes leukocyte adhesion and transmigration
4. Hypoxia produces inflammatory effect on endothelium

Question 9

What is the broad mechanism of action of heparins?

Answer 9

Potentiate antithrombin

Question 10

What is one risk of long term heparin use?

Answer 10

Osteoporosis

Question 11

Give an example of an anti-Xa drug

Answer 11

Rivaroxaban

Question 12

Give an example of an anti-IIa drug

Answer 12

Dabigatran

Question 13

How does warfarin affect vit K?

Answer 13

Prevents recycling of Vit K

Question 14

Which procoagulant factors fall as a result of warfarin medication?

Answer 14

II, VII, IX and X

Also Protein C and Protein S

Question 15

How is warfarin monitored?

Answer 15

INR measure

Question 16

Why should warfarin never be given to pregnant women?

Answer 16

It is teratogenic

Question 17

Give an example of an LMWH

Answer 17

Enoxaparin/ Tinzaparin

Question 18

What scoring system is used to calculate risk of thrombosis?

Answer 18

Chads-vasc

Question 19

Which surgeries carry the highest risk of thrombosis?

Answer 19

Orthopaedic

Question 20

Which surgeries carry highest risk of bleeding?

Answer 20

Neuro, spinal or eye surgery

Question 21

Which class of anti-coagulants carries a significantly lower risk of intracranial bleeding?

Answer 21

DOACs

Question 22

What is the best drug to use as a long-term anticoagulant in a patient who has had an idiopathic VTE?

Answer 22

DOACs

Question 23

Recall 3 minor precipitants of thrombosis

Answer 23

COPD
flights
trauma

Question 24

After someone has suffered a thrombosis due to a minor precipitant, how long should they be anti-coagulated for?

Answer 24

3 months

Question 25

Recall the order in which the different coagulation factors in the intrinsic pathway catalyse each other?

Answer 25

12
11
9
8
10

Question 26

Which coagulation measure is used to monitor heparin therapy?

Answer 26

APTT

Question 27

Which coagulation measure is used to monitor warfarin therapy?

Answer 27

PT (INR)

Question 28

Which factor does the extrinsic pathway start with?

Answer 28

Seven