Pathophysiology of thrombosis and embolism 1

Question 1

Normal blood flow is ________

Answer 1

Laminar

Question 2

What is stasis?

Answer 2

Stagnation of flow

Question 3

What is turbulence?

Answer 3

Forceful and unpredictable flow

Question 4

What are the causes of thromboembolism?

Answer 4

Thromboembolism (common)

Atheroma

Hyperviscosity

Spasm

External compression

Vasculitis

Vascular steal

Question 5

What are the factors in virchows traid that contribute to formation of blood clot?

Answer 5

Changes in the blood vessel wall

changes in the blood constituents

Changes in the pattern of blood flow.

Question 6

What is thrombosis?

Answer 6

Formation of solid mass from the constituents of blood within the vascular system during life

Question 7

What is an example of a disease that changes in the vessel wall can cause?

Answer 7

Atheromatous coronary artery

Question 8

What is the pathogenesis of thrombosis?

Answer 8

Endothelial injury

Stasis or turbulent blood flow

Hypercoagulability of the blood

Question 9

What can thrombosis cause?

Answer 9

Turbulent blood flow can cause Fibrin deposition and Platelet clumping

Loss of intimal cells leading to denuded plaque

Collagen exposed causing platelets to adhere

Fibrin meshwork causing RBCs to be trapped

Question 10

How does hypercholesterolaemia relate to thrombosis?

Answer 10

It increases the risk of atherosclerosis which is a major underlying cause of thrombotic events

Question 11

What is the relationship between atheroma and thrombosis?

Answer 11

Virchows traid plays a crucial role in the development of arterial thrombosis on atheromatous plaques.

Question 12

What can changes in blood constituents cause?

Answer 12

Hyper viscosity

Post-traumatic hypercoagubility

Question 13

What can turbulence cause?

Answer 13

Atheromatous plaque

Aortic aneurysm

Question 14

What can stasis lead to?

Answer 14

It is one of the factors that contribute to its development of economy class syndrome.

Question 15

Who are at a risk of developing deep vein thrombosis?

Answer 15

Post op patients due to low mobility after surgery

Question 16

What do the consequences of thrombosis depend on?

Answer 16

Site

Extent

Collateral circulation

Question 17

What is embolism?

Answer 17

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

Question 18

What is embolus?

Answer 18

Detached intravascular solid, liquid or gaseous mass

Factors causing embolism depend on type of embolus

Question 19

What are most emboli?

Answer 19

Dislodged thrombi which can cause thromboembolism

Question 20

What are the sources of systemic/arterial thromboembolism?

Answer 20

• Mural thrombus which is associated with MI or left atrial dilation and AF
• Aortic aneurysms
• Atheromatous plaques
• Valvular vegetations
• Venous thrombi which can lead to a paradoxical emboli

Question 21

What sites does systemic thromboembolism travel to?

Answer 21

Lower limbs (most common), brain and other organs

Question 22

What are the consequences of systemic thromboembolism
dependent on?

Answer 22

Vulnerability of affected tissue to ischaemia

Calibre of occluded vessel

Collateral circulation but usually infarction occurs.

Question 23

Where does venous thromboembolism
originate from?

Answer 23

Deep venous thromboses (lower limbs)

It is the most common form of thromboembolic disease

Question 24

Where does Venous thromboembolism travel to?

Answer 24

Pulmonary arterial circulation

Question 25

What is venous thromboembolism dependant on?

Answer 25

Size, it may occlude main pulmonary artery, bifurcation (saddle embolus), smaller arteries.

Question 26

What are the consequences of pulmonary thromboembolism depend on?

Answer 26

Size of embolus: silent, pulmonary haemorrhage/infarction, right heart failure, sudden death

Question 27

What does multiple pulmonary embolism cause over time?

Answer 27

Pulmonary hypertension

Right ventricular failure

Question 28

What are the risk factors for DVT and pulmonary thromboembolism?

Answer 28

• Cardiac failure
• Severe trauma/burns
• Post-Op/Post-partum
• Nephrotic syndrome
• Disseminated malignancy
• Oral contraceptive
• age
• Bed rest/ immobilisation
• Obesity
• Past medical history of DVT

Question 29

What are the prophylaxis given to surgical patients at risk of DVT and pulmonary thromboembolism?

Answer 29

TEDS and S/C heparin

Question 30

What can major fractures cause?

Answer 30

Syndrome of fat embolism

The brain, kidneys and skin are affected