Thrombotic disorders Flashcards
What are the elements of haemostasis?
○ Primary haemostasis - Vasoconstriction - Platelet adhesion - Platelet aggregation ○ Blood coagulation - Insoluble fibrin formation - Fibrin cross-linking ○ Fibrinolysis
What is the definition of thrombus?
clots forming in the wrong places
What is a thromboembolism?
Movement of a clot along a vessel
What is Virchow’s triad?
even just one of these can result in a clot - Stasis □ Bed rest □ Travel - Hypercoagubility □ Pregnancy □ Trauma - Vessel damage □ Atherosclerosis
What is arterial thrombus?
○ ‘White clot’~ platelets and fibrin
○ Results in ischaemia and infarction
○ Principally secondary to atherosclerosis
○ Examples
Give examples of arterial thrombus
- Coronary thrombosis: □ MI □ Unstable angina - Cerebrovascular thromboembolism: □ Stroke □ Transient ischaemia - Peripheral embolism □ Limb ischaemia
What are the risk factors for arterial thrombus?
- Age
- Smoking
- Sedentary lifestyle
- Hypertension
- Diabetes mellitus
- Obesity
- Hypercholesterolaemia
What is the managment of arterial thrombus?
- Primary prevention □ Lifestyle modification □ Treatment of vascular risk factors - Acute presentation □ Thrombolysis □ Thrombectomy □ Antiplatelet/anticoagulant drugs - Secondary prevention
What is venous thrombus?
○ ‘Red thrombus’~ fibrin and red cells
○ Results in back pressure
○ Principally due to stasis and hypercoagulability
Give examples of venous thrombus
- Limb deep vein thrombosis
- Pulmonary embolism
- visceral venous thrombosis
- intracranial venous thrombosis
- superficial thrombophlebitis
What are the risk factors for venous thrombus?
- Increasing age
- Pregnancy
- Hormonal therapy (COCP/HRT)
- Tissue trauma
- Immobility
- Surgery (up to 12 weeks)
- Obesity
- Systemic disease
□ Cancer
□ Myeloproliferative Neoplasm (MPNs)
□ Autoimmune disease:
® Inflammatory bowel disease
® Connective tissue disease e.g. SLE
® Antiphospholipid syndrome: arterial and venous thrombosis - Family history
How do you diagnose venous thrmbus?
- Pretest probability scoring □ Wells score □ Geneva score - Laboratory testing if pretest probability low □ D-dimer □ Ventilation/ perfusion scan □ CT pulmonary angiography - Imaging
What are the aims of managment for venous thrombus?
□ Prevent clot extension
□ Prevent clot embolisation
□ Prevent clot recurrence in long term treatment
What drugs are used in the treatment of venous thrombus?
□ Anticoagulants ® LMWH ® Coumarins (warfarin) ® DOACs (direct oral anticoagulants) □ Thrombolysis only in selected cases ® Massive PE
What is heritable thrombophilia?
An inherited predisposition to venous thrombosis
