Pathophysiology of Coagulation + Haemostasis Flashcards
What is thrombosis?
Pathological formation of a intravascular blood clot
What are the 3 things that cause thrombosis?
Disruption of blood flow (stasis)
Endothelial cell damage
Hypercoagulable states
What may cause disruption to blood flow?
Immobilisation (flight, bedrest)
Cardiac wall dysfunction
Aneurysm
AF
What may cause endothelial cell damage?
Inflammation
Cigarette smoke
Cytokines
Atherosclerotic plaque
What may cause hypercoagulable states?
Any disease process that leads to an increased blood clot formation
What are hypercoagulable states because of?
Excessive procoagulant factors or defective anticoagulant
What are hypercoagulable states?
Inherited or acquired disease
What is the classic presentation of hypercoagulable states?
Recurrent DVT or DVTs at young age
What does Alteplase do?
Break down clots
When should Alteplase be used after an ischaemic stroke?
Only if it can be within 4.5hrs of symptom onset
What is the 1st choice for the treatment of a venous thrombus?
Rivaroxaban
Apixaban
What are venous clots the most common cause of?
Stasis of blood
Where is the most common site for venous thrombus?
Deep veins on lower limb
What are venous thrombus mostly made of?
Fibrin
What are arteriole thrombus mostly made of?
Platelets
What are arteriole thrombus mostly due to?
Endothelial damage
Why is aspirin used for arteriole thrombus?
As it is an inhibitor of platelet aggregation
What is an embolism?
Blockage caused by anything that breaks off = emboli
What is a pulmonary embolism?
Intravascular mass that travels + occludes pulmonary blood vessels
What are the functions of thrombin?
Acts on fibrinogen to produce fibrin monomers
Activates 13a
Strengthens blood clot
What are the functions of plasmin?
Breaks down clot
How does plasmin break down the clot?
Cleaves fibrin + fibrinogen into FDPs
= form fragments = D-dimers
What is thrombin switched off by?
Natural anticoagulant antithrombin3
= limits clot formation
What are the 3 main stages of platelet aggregation?
Adhesion
Release reaction
Aggregation