Pathophysiology of Thrombosis

Question 1

What is normal blood flow?

Answer 1

Laminar (smooth and ordered with cells in the middle)

Question 2

What are the 2 kinds of abnormal blood flow?

Answer 2

Stasis

Turbulence

Question 3

What is stasis blood flow?

Answer 3

Stagnation of flow, meaning blood flow slows down or stops

Question 4

What is turbulence blood flow?

Answer 4

Forceful, unpredictable flow

Question 5

What could defects in blood flow be due to?

Answer 5

Thromboembolism

Atheroma

Hyperviscocity

Spasm

External compression

Vasculitis

Vascular steal

Question 6

What are the factors that cause thrombosis known as?

Answer 6

Virchow’s triad

Question 7

What are the different components of Virchow’s Triad?

Answer 7

Changes in the blood vessel wall

Changes in the blood constituents

Changes in the pattern of blood flow

Question 8

What is an example of changes in the blood vessel wall as part of Virchow’s triad?

Answer 8

Atheromatous coronary artery

Question 9

What is an example of changes in blood constituents as part of Virchow’s triad?

Answer 9

Hyperviscocity

Post traumatic hypercoagulability

Question 10

What is an example of changes in blood flow as part of Virchow’s triad?

Answer 10

Stasis or turbulence

Question 11

What is thrombosis?

Answer 11

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

Question 12

What is the formation of a solid mass from the constituents of blood within the vascular system during life called?

Answer 12

Thrombosis

Question 13

What can a thrombus easily be confused with?

Answer 13

Blood clot - they are two different things

Question 14

What is the pathogenesis of thrombosis?

Answer 14

1) Turbulent blood flow (fibrin deposition, platelet clumping)
2) Loss of intimal cells, denuded plaque
3) Collagen exposed, platelets adhere
4) Fibrin meshwork, red blood cells trapped
5) Alternating bands (lines of Zahn)
6) Further turbulence and platelet deposition
7) Propagation
8) Consequences

Question 15

What commonly leads to thrombus?

Answer 15

Hypercholesteroaemia

Question 16

What is the relationship between atheroma and thrombosis?

Answer 16

Arterial thrombosis is usually laid over an atheroma

Question 17

What does the consequences of a thrombus depend on?

Answer 17

Site

Extend

Collateral circulation

Question 18

What are some common clinical scenarioes of thrombosis?

Answer 18

Deep vein thrombosis

Ischaemic limb

Myocardial infarction

Question 19

What are the potential outcomes of thrombosis?

Answer 19

Resolution

Organisation

Death

Propagation (turns to embolism)

Question 20

What is an embolism?

Answer 20

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

Question 21

What is the movement of abnormal material in the bloodstream and its impaction in a vessel (blocking the lumen) called?

Answer 21

Embolism

Question 22

What are most emboli?

Answer 22

Dislodged thrombi (thromboembolism)

Question 23

What do factors causing the embolism depend on?

Answer 23

Type of embolism

Question 24

What are different types of embolism?

Answer 24

Thrombus

Fat

Gas

Tumour

Trophoblast

Septic material

Amniotic fluid

Bone marrow

Foreign bodies

Question 25

What are the two different kinds of embolism caused by thrombus?

Answer 25

Systemic/arterial thromboembolism Venous thromboembolism

Question 26

Where do aortic embolisms travel to?

Answer 26

Wide variety of sites, lower limbs being most common, could go to the brain

Question 27

What do consequences of arterial thromboembolism depend on?

Answer 27

Vulnerability of affected tissues to ischaemia Calibre of occluded vessel

Question 28

Where do venous thromboembolisms originate from?

Answer 28

Deep venous thrombosis (lower limbs)

Question 29

Where do venous thromboembolisms travel to?

Answer 29

Pulmonary arterial circulation

Question 30

What do consequences of venous thromboembolism depend on?

Answer 30

Size of embolus

Question 31

What could the consequences of venous thromboembolism be?

Answer 31

Silent Pilmonary haemorrhage/infarction Right heart failur Sudden death

Question 32

What does multiple pulmonary embolism over time lead to?

Answer 32

Pulmonary hypertension and right ventricular failure

Question 33

What are examples of gas embolism?

Answer 33

Decompression sickness (N₂ forms as bubbles which lodge in capillaries) Air embolus

Question 34

What is a trophoblast?

Answer 34

Cells forming the outer layer of a blastocyst

Question 35

What are the cells forming the outer layer of a blastocyst called?

Answer 35

Trophoblast

Question 36

What is infarction?

Answer 36

Obstruction of the blood supply to an organ causing local death of the tissue

Question 37

What is obstruction of the blood supply to an organ causing local death to the tissue called?

Answer 37

Infarction

Question 38

What are some risk factors for deep vein thrombosis and pulmonary embolism?

Answer 38

Cardiac failure Severe trauma/burns Post operation Nephrotic syndrome Disseminated malignancy Oral contraceptives Increasing age Bed rest/immobilisation Obesity Past medical history of deep vein thrombosis

Question 39

What is used as prophylaxis for surgical patients at risk of deep vein thrombosis?

Answer 39

TEDS S/C heparin

Question 40

What is prophylaxis?

Answer 40

Treatment or action to prevent disease

Question 41

What is treatment or action to prevent disease called?

Answer 41

Prophylaxis