pathophysiology of thrombosis and embolism Flashcards
true or false, normal blood is turbulant?
false, blood flow is LAMINAR
what would be stasis of blood flow mean?
stagnation of flow
what would turbulent blood flow mean?
forceful, unpredictable flow
what would lead to defects in blood flow?
hromboembolism common
Other causes:
Atheroma
Hyperviscosity, spasm, external compression, vasculitis, vascular steal
what is the virchows triad?
Changes in the blood vessel wall
Changes in the blood constituents
Changes in the pattern of blood flow
what are the factors that cause thrombosis?
virchows triad
what is the pathogenesis of thrombosis?
Endothelial injury
Stasis or turbulent blood flow
Hypercoagulability of the blood
what do the consequences of thrombosis depend on?
Site
Extent
Collateral circulation
what is an embolus?
detached intravascular solid, liquid or gaseous mass
what are the types of embolus?
Systemic/Arterial Thromboembolus Venous Thromboembolus fat gas air
what are characteristics of systemic thromboembolus?
Travel to wide variety of sites: lower limbs most common, brain, other organs
Consequences depend on vulnerability of affected tissues to ischaemia, calibre of occluded vessel, collateral circulation but usually infarction occurs
what are characteristics of venous thromboembolus?
Originate from deep venous thromboses (lower limbs)
Travel to the pulmonary arterial circulation
Depending on size, may occlude main pulmonary artery, bifurcation (saddle embolus), smaller arteries
Most common form of thromboembolic disease
venous thromboembolus
what does pulmonary thromboembolism depend on
size of embolus: silent, pulmonary haemorrhage/infarction, right heart failure, sudden death
what are risk factors for DVT and pulmonary embolism
Cardiac failure, severe trauma/burns, post-op/post-partum, nephrotic syndrome, disseminated malignancy, oral contraceptive, age, bed rest/immobilisation, obesity, PMH of DVT
Prophylaxis for surgical patients at risk: TEDS, s/c heparin
