Venous Thrombosis Flashcards
What are the types of thrombotic events?
Arterial = coronary, cerebral, peripheral Venous = DVT, PE
What kind of pressure systems are the vascular systems?
Arterial = high pressure Venous = low pressure
What are the features of arterial thromboses?
Atherosclerosis = cholesterol pushed into vessel walls
Platelet rich thrombus
What is the treatment of arterial thrombosis?
Aspirin and other anti-platelets = modify risk factors for atherosclerosis
What are the features of venous thrombosis?
No atherosclerosis as low pressure
Activates coagulation cascade = clot rich in fibrin
Platelets not activated
What are the risk factors for venous thrombosis?
Stasis, vessel wall (valve degeneration), hypercoagulability
What are the symptoms of a DVT?
Hot, swollen and tender limb
Pitting oedema
What can a DVT lead to?
May embolise and cause a PE = pulmonary infarction, pleuritic chest pain, CV collapse, right heart failure, hypoxia
What age group are VTEs more common in?
Older patients = risk increases with age
What are the risk factors for VTE?
Age, obesity, pregnancy, puerperium, oestrogen therapy, previous DVT/PE, trauma/surgery, malignancy, paralysis, infection, thrombophilia
What is hypercoagulability associated with?
Tissue factor release, raised vWF and factor VIII
What are thrombophilias?
Disorders of haemostatic mechanism which are likely to predispose to thrombosis
What are the mechanisms of thrombophilia?
Increased coagulation activity = primary or secondary haemostasis
Decreased fibrinolytic activity = rare
Decreased anticoagulant activity = most common
What is the co-factor of protein C?
Protein S
What causes factor V leiden?
Single base pair change = factor V works normally in haemostasis but doesn’t bind as well to protein C for anticoagulation