Thrombosis and embolism

Question 1

How is normal blood flow described

Answer 1

Laminar

Question 2

What are the two types of abnormal blood flow?

Answer 2

Turbulence

Stasis

Question 3

What can cause abnormal blood flow?

Answer 3

Thromboembolism
Atheroma
Hyperviscosity, spasm, external compression, vasculitis

Question 4

What three components make up Virchow’s triad?

Answer 4

Changes in blood vessel wall
Changes in the blood constituents
Changes in the pattern of blood flow

Question 5

What is a thrombus

Answer 5

A solid mass from the constituents of blood within the vascular system during life - all three components of Virchow’s triad

Question 6

Pathogenesis of Thrombosis

Answer 6

Endothelial injury
Stasis or turbulent blood flow
Hypercoagulability of the blood

Question 7

Example of thrombosis formation in an atheromatous coronary artery

Answer 7

Turbulent blood flow 
Loss of intimal cells, denuded plaque
Collagen exposed, platelet adhere
Fibrin meshwork, RBCs trapped
Alternating bands: lines of Zahn
Further turbulence and platelet deposition
Propagation
Consequences

Question 8

What are 3 common clinical scenarios of thrombosis

Answer 8

DVT
ischaemic limb
MI

Question 9

What is embolism?

Answer 9

Movement of abnormal material in the bloodstream and its impaction in a vessel, blocking its lumen

Question 10

What is an embolus

Answer 10

detached intravascular solid, liquid or gaseous mass

Question 11

Name the types of thromboembolus

Answer 11

systemic/arterial
Systemic
Venous thrombus

Question 12

What are the sources of a systemic/arterial thromboembolus

Answer 12

mural thrombus
aortic aneurysm
atheromatous plaques
valvular vegetations

Question 13

Where do systemic thromboemboli most commonly travel to?

Answer 13

lower limbs

Question 14

Where do venous thromboembolus originate and travel to

Answer 14

lower limbs to pulmonary arterial circulation

Question 15

Potential consequences of pulmonary thromboembolism

Answer 15

Silent
Pulmonary haemorrhage/ infarction
Right heart failure
Sudden death

Question 16

Risk factors for DVT and pulmonary thromboembolism

Answer 16

Cardiac failure
Severe trauma
Post-op
Nephrotic syndrome
Disseminated malignancy
Oral contraceptive
Age
Bed rest/immobilisation
Obesity

Question 17

Other types of embolus (not thrombus)

Answer 17

fat
gas
air
tumour
trophoblast
septic material
amniotic fluid
bone marrow
foreign bodies