Haemostasis and Thrombosis

Question 1

Examples of alterations to blood in Virchows triad that make it more coagulable?

Answer 1

Polycythaemia

Factor V leiden

Question 2

Examples of alterations to vessel wall in Virchows triad that make it more coagulable?

Answer 2

Infection, malignancy, vasculitis, trauma

Question 3

How does reduced blood flow cause coagulation

Answer 3

Activated blood factors accumulate rather than washed away

Question 4

Prophylactic vs treatment of thromboembolic event

Answer 4

Prophylactic- LMWH- lower dose, TED stockings
Treatment- LMWH treatment dose followed by Warfarin or DOAC- 3 months if known, possibly lifelong if unknown, cancer- can be until in remission

Question 5

INR target for anticoagulant treatment

Answer 5

2. 5- 1st episode DVT or PE, atrial fibrillation

3. 5- Recurrent DVT or PE, mechanical prosthetic valve

Question 6

Mechanism of action of anticoagulants

Answer 6

Heparin- anti-thrombin activator
Dabigatarn- anti- factor 2
Riv/Apix- anti-10
Warfarin- prevents vit K synthesis- prevents formation of factors 2,7,9,10