Pathophysiology of Thrombosis and Embolism Flashcards
What is normal blood flow called?
Laminar
What are the two different abnormal types of blood flow called?
Stasis
Turbulence
What is stasis blood flow?
Stagnation of flow
What is turbulent blood flow?
Forceful, unpredictable flow
What causes defects in blood flow?
Thromboembolism Atheroma Hyperviscosity Spasm External compression Vasculitis Vascular steal
What effects Virchow’s Triad?
Changes in the blood vessel wall
Changes in the blood constituents
Changes in the pattern of blood flow
How do the factors causing a thrombus relate to Virchow’s triad?
Endothelial injury
Hypercoagulability of the blood
Stasis or turbulent blood flow
What do the consequences of thrombosis depend on?
Site
Extent
Collateral circulation
What are the different types of embolus?
Systemic/arterial Thromboembolus Venous Thromboembolus Fat embolus Gas embolus Tumour Septic material Amniotic fluid Bone Marrow Foreign bodies
What is the result of the propagation of thrombosis?
Embolism
What is an embolism?
Movement of abnormal material in the bloodstream and its impaction in a vessel blocking its lumen
What is a thromboembolism?
Dislodged thrombi
What are the causes of a systemic thromboembolism?
Mural thrombus
Aortic aneurysm
Atheromatous plaques
Valvular vegetations
What is a mural thrombus?
A thrombus on the endocardial lining of the heart chambers or on the wall of a la
age blood vessel without occlusion
What conditions is a mural thrombus associated with?
MI
Left atrial dilatation
Atrial fibrillation
What is valvular vegetation?
Abnormal growth in the valves of the heart
What is the most common form of thromboembolic disease?
Venous thrombombolus
Where does a venous thromboembolus originate from?
Deep venous thromboses in the legs
Where does a venous thromboembolus travel to?
The pulmonary circulation
What can multiple pulmonary emboli cause over time?
Pulmonary hypertension
Right ventricular failure
What are the consequences of a pulmonary embolism?
Pulmonary haemorrhage
Pulmonary infarction
Right heart failure
Sudden death
What are the risk factors for DVT and Pulmonary thromboembolism?
Cardiac failure Severe trauma Severe burns Post-op/post-partum Oral contraceptive Old age Immobilisation Obesity Past history of DVT
What is the prophylaxis for surgical patients at risk of DVT or PE?
Thromboembolic disease support
S/C heparin
When does a fat embolus occur?
After a major fracture
What does a fat embolus effect?
Brain
Kidneys
Skin
What are arterial gas emboli also called?
Decompression sickness
What can cause air emboli?
Head and neck wounds
Surgery
Central venous lines
How are atheroma and thrombosis related?
Thrombosis is usually superimposed on an atheroma, specifically arterial thrombosis
What is thrombosis?
Formation of a solid mass from the constituents of blood within the vascular system during life
Give an example of a change in vessel walls that causes thrombosis?
Atheromatous coronary artery
What change in the blood constituents can cause thrombosis?
Hypercholesterolaemia
Hypercoagulability
Hyperviscosity
What is economy class syndrome?
Periods of prolonged immobility on long-haul flights that cause stasis of blood so can causes thrombosis
How does turbulence and stasis cause thrombosis?
They distrust laminar flow and bring platelets into contact with the endothelium
What are the possible outcomes of thrombosis?
Resolution
Organisation/recanalisation
Death
