Thrombotic Disorders Flashcards
(37 cards)
What are the elements of haemostasis?
- Primary haemostasis
- Blood coagulation
- Fibrinolysis
What is involved in primary haemostasis?
- Vasoconstriction
- Platelet adhesion
- Platelet aggregation
What is involved in coagulation?
- Insoluble fibrin formation
- Fibrin cross-linking
How does fibrinolysis take place?
- Urokinase, tPA and factor XII convert plasminogen to plasmin
- Plasmin converts fibrin to fibrinogen/fibrin degradation products
Thrombus
Clot arising in the wrong place
Thromboembolism
Movement of clot along a vessel
What are the 3 components of Virchow’s triad?
- Stasis
- Hypercoagulability
- Vessel damage
What contribute to stasis?
- Bed rest
- Travel
What contributes to vessel damage?
Atherosclerosis
What contributes to hypercoagulability?
- Pregnancy
- Trauma
What are the 3 types of thrombosis?
- Arterial
- Venous
- Microvascular
What is an arterial clot formed of?
White clot= platelets and fibrin
What do arterial clots result in?
Ischaemia and infarction
What are arterial clots usually secondary to?
Atherosclerosis
Give examples of arterial thromboembolism.
Coronary thrombosis
- MI
- Unstable angina
Cerebrovascular thromboembolism
- Stroke
- Transient ischaemia
Peripheral embolism
-Limb ischaemia
What are the risk factors fro arterial thrombosis?
- Age
- Smoking
- Sedentary lifestyle
- Hypertension
- Diabetes mellitus
- Obesity
- Hypercholesterolaemia
How is arterial thrombosis managed?
Primary prevention
- Lifestyle modification
- Treatment of vascular risk factors
Acute presentation
- Thrombolysis
- Antiplatelet/anticoagulant drugs
Secondary prevention
What are venous thrombi formed of?
Red thrombus= fibrin and RBC
What does venous thrombosis result in?
Back pressure
What is venous thrombosis principally due to?
Stasis and hypercoagulability
Give examples of venous thromboembolism.
Limb deep vein thrombosis
- Pulmonary embolism
- Visceral venous thrombosis
- Intracranial venous thrombosis
- Superficial thrombophlebitis
What are the risk factors for venous thrombosis (stasis and hypercoagulability)?
- Increasing age
- Pregnancy
- Hormonal therapy (COCT/HRT)
- Tissue trauma
- Immobility
- Surgery
- Obesity
- Systemic disease
- Family history
What systemic diseases are associated with increased risk of venous thrombosis?
Cancer
Myeloproliferative neoplasm
Autoimmune disease
- Inflammatory bowel disease
- Connective tissue disease e.g SLE
- Antiphospholipid syndrome: arterial and venous thrombosis
How is venous thrombosis diagnosed?
Pretest probability scoring
- Wells score
- Geneva score
Lab test if probability low
-D-dimer
Imaging
- Doppler US
- V/Q scan
- CT pulmonary angiogram
