Thrombosis Flashcards
What are the 3 components f Virchow’s Triad?
Stasis
Hypercoagulability
Vessel wall damage
In a venous thrombus, the clot will be rich in _____?
Fibrin
In an arterial thrombus the lot will be rich in ____
Platelets
List some risk factors for venous clots:
Stasis e.g. post surgery Age Pregnancy Obesity Oestrogen therapy Previous DVT/PE Trauma Malignancy Paralysis Infection Thrombophilia
What is the lifetime risk of an average person for developing venous thrombo-embolism?
1/1000 per year
2.5% in a lifetime
What are some clinical features of a DVT?
Unilateral
Swollen leg
Erythromatous
Hot and tender
List some clinical features of a pulmonary embolism?
Pleuritic chest pain Hypoxia Tachypnoea Collapse Right sided heart strain Death
Define thrombophilia:
Familial or acquired disorder of the haemostatic mechanism, which predisposes you to thrombosis
e.g. anti-phospholipid syndrome
List some naturally occurring anti-coagulants:
Serine protease inhibitors
Protein C
Protein S
List some genetic defects which increases an individuals tendency to develop premature, unusual and recurrent thrombosis:
Factor V Leidin
Prothrombin 20210 mutation
Anti-thrombin deficiency
Protein C or S deficiency
When might you give a patient prophylaxis for thrombosis?
If theyre pregnant
When should you prescribe a patient with long term anticoagulation?
If they have recurrent episodes of thrombotic events
List some clinical features of anti-phospholipid syndrome:
Recurrent thromboses
Recurrent foetal loss
Mild thrombocytopaenia
List some conditions associated with anti-phospholipid antibodies:
Autoimmune disorders e.g. SLE
Lymphoproliferative disorders
Viral infection
What are anti-phospholipid antibodies?
They are autoantibodies which have a specificity for anionic phospholipids, and they prolong the phospholipid dependent coagulation tests in vitro.
(aka lupus anticoagulants)
What protein is involved in anti-phospholipid antibodies?
Beta2-glycoprotein
Leads to activation of primary and secondary haemostasis
Also causes vessel wall abnormalities
Give some reasons why you might consider screening for hereditary thrombophilia?
Venous thrombosis <45 y/o
Recurrent / unusual venous thrombosis
Family history of venous thrombosis or thrombophilia
How is antithrombin involved in increasing the risk of thrombosis?
Antithrombin switches off thrombin which then switches of haemostasis.
Low levels of antithrombin increase risk of coagulation due to stasis
What activates proteins C and S?
Thrombin binds to thrombomodulin which then activates Protein’s C and S to switch off coagulation.
