Haematology- Thrombotic Disorders Flashcards
What makes up Virchow’s triad?
Stasis of blood
Vessel damage
Hypercoagulability
->Virchow’s triad contributes to thrombus formation leading to a clot
What can cause stasis of blood?
Bed rest
Travel
What can cause hypercoagulability of blood?
Pregnancy
Trauma
What can cause vessel damage?
Atherosclerosis
What are the three elements of haemostasis?
Primary haemostasis
Blood coagulation
Fibrinolysis
What are the three steps of primary haemostasis?
Vasoconstriction
Platelet adhesion
Platelet aggregation
What are the two steps of coagultion?
Insoluble fibrin formation
Fibrin cross-linking
What is an arterial thrombus?
A clot made of platelets and fibrin
Results in ischaemia and infarction
What does an arterial thrombus usually occur secondarily to?
Atherosclerosis
There are different risk factors for venous and arterial thrombosis.
What are the risk factors for arterial thrombsosi?
Age
Smoking
Sedentary lifestyle
Hypertension
Diabetes
Obesity
Hypercholesterolaemia
What are some examples of conditions which are caused by arterial thromboembolism?
MI
Unstable angina
Stroke/TIA
Limb ischemia
Primary prevention of arterial thromboembolism?
Lifestyle modification
Treatment of vascular risk factors
What is the management for an acute presentation of an arterial thromboembolism?
->e.g. seen in stroke, MI, etc.
Thrombolysis
Antiplatelet/anticoagulant drugs
Which factors cause venous thrombus?
Stasis and hypercoagulability of blood
What are some specific types of venous thromboembolism?
Limb deep vein thrombosis
Pulmonary embolism
Risk factors for venous and arterial thrombosis differ.
What are some of the risk factors for venous thrombosis?
Increasing age
Pregnancy
Hormonal therapy e.g. COCP, HRT
Tissue trauma
Immobility
Surgery
Obesity
Systemic disease
FH
Name some systemic diseases which increase risks of venous thrombosis.
Cancer
Myeloproliferative Neoplasm (MPNs)
Autoimmune disease e.g. IBD, connective tissue disease (SLE), antiphospholipid syndrome
->antiphospholipid syndrome increases risks of both venous and arterial thrombosis
–> also, pretty sure Amy Dowden had a PE when she was recovering from breast cancer so that’s useful to remember
How is a diagnosis of venous thrombosis made?
D-Dimer
Imaging- Doppler US
Pretest probability scoring: Wells score or Geneva score
->issue with D-dimer is it can be raised in other conditions e.g. cancer, infection. D-Dimer usually done after pretest probability
Which investigation is good in the diagnosis of PE?
V/Q scan (ventilation/perfusion scan)
CT Pulmonary Angiogram can also be used
Which drugs are used om the management in venous thrombosis?
Anticoagulants- LMWH, warfarin, DOACs
When may thrombolysis be used in management of venous thrombosis?
Only in selected cases e.g. massive PE
Give some examples of DOACs.
Apixaban
Rivaroxaban
->most widely used anticoagulants
Which patients would require warfarin rather than DOACs as anticoagulants?
Patients with metallic heart valves
Renal failure
Anti-phospholipid syndrome
Why is thrombolysis only really used in arterial thrombosis?
High risk of bleeding- benefits outweigh risks for arterial thrombosis but not venous thrombosis
