Thrombus and Embolism

Question 1

What is virchows triad?

Answer 1

Promotes thrombosis.

• changes in blood constituents
• changes in pattern of blood flow
• Change in blood vessel wall

Question 2

What is changes in blood constituents caused by?

Answer 2

Hypercoagubility.

• hyper viscosity, post tramtic hyerviscosity

Question 3

What is changes in pattern of blood flow cause by?

Answer 3

stasis caused by - Post operation

turbulence caused by - atheromatous plaque, Pritchard aneurysm

Question 4

What can thrombosis lead to?

Answer 4

Myocardial infarction, DVT, ischaemic limb

Question 5

What can be the outcomes of thrombosis?

Answer 5

• resolution
• organisation/ recanalisation
• propagation = embolism/

Question 6

What are most emboli?

Answer 6

• dislodged thrombus

Question 7

what are sources of systemic/arterial thromboembolism?

Answer 7

• Mural thrombus (usually in the walls of aorta and heart, associated with left atrial dilatation and AF, myocardial infarction
• Aortic aneurysms
• valvular vegetations

Question 8

Where do systemic thromboembolis usually travel?

Answer 8

• lower limbs most commonly.

- Brain

Question 9

What usually occurs in systemic thromboembolism?

Answer 9

Infarction (necrosis of tissue)

Question 10

What are the types of embolus?

Answer 10

• venous thromboembolus
• fat (major fractures)
• gas
• air(head and neck wounds, surgery)
• septic material e.g. in infective endocarditis
• trophoblast in pregnant women ,lungs
• tumour
• Amniotic Fluid (Cause of collapse (+/- death) in childbirth)
• Bone Marrow ( Fractures; CPR)
• Foreign Bodies (Intravascular cannulae tips, sutures)

Question 11

Most common form of thromboembolic disease?

Answer 11

venous thromboembolus

• originate from deep vein in legs
• Travel to the pulmonary arterial circulation
• may occlude main pulmonary artery, bifurcation (saddle embolus), smaller arteries

Question 12

Consequences of pulmonary thromboembolism?

Answer 12

depend on size of embolus: silent, pulmonary haemorrhage/infarction, right heart failure, sudden death
Multiple PE over time: pulmonary hypertension and right ventricular failure

Question 13

Risk factors for DVT and pulmonary thromboembolism?

Answer 13

• Cardiac failure
• severe trauma/burns
• post-op/post-partum
• nephrotic syndrome
• disseminated malignancy
• oral contraceptive, increasing age, bed rest/immobilisation, obesity, PMH of DVT

Prophylaxis for surgical patients at risk: TEDS, s/c heparin