haemostasis - thrombosis

Question 1

how do disorders of thrombosis present?

Answer 1

Pulmonary 
Embolism (PE):
Tachycardia
Hypoxia
Shortness of breath
Chest pain (pruitic, worse when taking a breath)
Haemopysis
Sudden death

Deep Vein Thrombosis (DVT):
Painful leg
Swelling
Red
Warm
May embolise to lungs
Post thrombotic syndrome

Most people die with a ‘haemostatic end-point’

also ones that cover stroke and MI

Question 2

what is thrombosis?

Answer 2

Intravascular coagulation

Inappropriate coagulation

Venous (or arterial)

Obstructs flow

May embolise to lungs

Question 3

what is virchows triad?

Answer 3

contains the three contributary factors to thrombosis:

Blood - dominant in venous thrombosis

vessel wall - dominant in arterial thrombosis

blood flow - contributes to both arterial and venous thrombosis

Question 4

what is thrombophilia?

Answer 4

Increased risk of venous thrombosis

presents with:
Thrombosis at young age
‘spontaneous thrombosis’
 Multiple thromboses
Thrombosis whilst anticoagulated

Question 5

why might the haemostatic balance tip towards venous thrombosis?

Answer 5

1. decrease in Fibrinolytic factors
Anticoagulant proteins:
Antithrombin
Protein C 
Protein S

2. increase in Coagulant factors
Platelets:
Factor VIII
Factor II
Factor V Leiden 
(increase activity due to activated protein C resistance)
Myeloproliferative disorders (plts )

Question 6

what are the main anticoagulant proteins?

Answer 6

Protein C
its cofactor protein S:
these inactivate factor Va and VIIIa

antithrombin:
inactivates thrombin (IIA) and Xa

Question 7

what are the baseline risks for venous thrombosis in 20 year olds and 60 year olds?

Answer 7

20 yrs:
1/10000

60 yrs:
1/1000

antithrombin deficiency is more likely to lead to a venous thrombosis than protein C and S

Question 8

what is the role of the vessel wall in venous thrombosis?

Answer 8

We know little about the role of the vessel wall in venous thrombosis.

Many proteins active in coagulation are expressed on the surface of endothelial cells and their expression altered in inflammation (TM, EPCR, TF)

Question 9

how does blood flow contribute to venous thrombosis?

Answer 9

Reduced flow (stasis) increases the risk of thrombosis
	e.g. surgery, long haul flight, pregnancy

Question 10

how do we treat venous thrombosis?

Answer 10

Prevention:

Assess and prevent risks

Prophylactic anticoagulant therapy

Reduce risk of recurrence/extension:

lower procoagulant factors
e.g.: warfarin, DOACs

increase anticoagulant activity
e.g: heparin