Thrombosis & Embolism Flashcards
What is the definition of “thrombosis”?
A solid mass of blood from the constituents of blood within the circulatory system, during life
NOT A CLOT
What are the three fundamental predisposing factors to thrombosis?
Hint: “Virchow’s Triad”
Abnormalities of blood vessel walls: Atheroma, direct injury, inflammation
Abnormalities of blood flow: Stagnation, turbulence
Abnormalities of blood components: smoking, post-partum, post-op
How do thrombi appear in arteries compared to how they appear in veins?
Arterial: pale, granular, lines of Zahn, lower cell content
Venous: soft, gelatinous, deep red, higher cell content
What are the outcomes of thrombosis?
Hint: “PROPEL”
Propagation: progressive spread of thrombosis, occurs in the direction of blood flow
Recanalisation: blood flow is reestablished but usually incompletely
Organisation: reparative process, ingrowth of fibroblasts and capillaries
Embolism: part of the thrombus breaks off and travels through the blood stream to a distant site
Lysis: complete dissolution of the thrombus, blood flow reestablished
What are the effects of thrombosis in the arterial and the venous system?
Arterial:
- Ischaemia
- Infarction (depending on the site and collateral circulation)
Venous:
- Congestion
- Oedema
- Ischaemia (once tissue pressure=arterial pressure, no blood flow)
- Infarction
What is the definition of “embolism” ?
Embolism is the blockage of a blood vessel by solid, liquid or gas at a site DISTANT from its origin
About how many percent of emboli are as the result of a thrombus?
> 90%
What can cause an embolism?
Thrombus Air Amniotic fluid Nitrogen Medical equipment Tumour cells Fat
Where would thrombo-emboli usually travel to if it originates in the systemic veins?
The lungs to cause pulmonary embolism (PE)
Where would thrombo-emboli usually travel to if it originates in the heart?
Renal, mesenteric and other arteries
Where would thrombo-emboli usually travel to if it originates in a carotid artery?
To the brain
Where would thrombo-emboli usually travel to if it originates in the abdominal aorta?
Arteries of the legs
What are some predisposing factors to DVT?
How is it treated?
Immobility, oral contraceptives, severe burns, post- op, cardiac failure IV heparin (short term) & oral warfarin (long term)
Recurrent PE might lead to what?
Pulmonary hypertension
Why might a patient get a fat embolism?
If they have fractures a long bone which releases bone marrow and can then travel to distal sites
