Thromboembolic diseases

Question 1

What is an ecchymosis?

Answer 1

A common type of bruise

Question 2

What is meant by a blood clot?

Answer 2

A build up of coagulated blood that forms outside of the blood vessels

Question 3

What is meant by a thrombus?

Answer 3

A build up of coagulated blood that forms inside the blood vessels

Question 4

What measurement is used to measure the intrinsic pathway of the coagulation cascade?

Answer 4

Prothrombin Time (PT)

Question 5

What measurement is used to measure the extrinsic pathway of the coagulation cascade?

Answer 5

Activated Partial Thromboplastic Time (APTT)

Question 6

What is Virchow’s triad of thrombosis risk factors?

Answer 6

-Endothelial injury
-Stasis
-Hypercoagulable blood

Question 7

What are some primary conditions that can cause hypercoagulable blood?

Answer 7

Factor V Leiden
Protein C deficiency
Protein S deficiency
Antithrombin III deficiency

Question 8

What are some secondary causes of hypercoagulable blood?

Answer 8

Prolongued immobility
Significant tissue injury
Anti-phospholipid syndrome
Myocardial infarction
Atrial Fibrillation
Cancer
Oral contraceptives
Smoking
Renal diseases
Cardiomyopathy

Question 9

What are some ways in which cancer can cause hypercoagulable blood?

Answer 9

Tumours produce:
- Tumour Produced Tissue Factor
- Mucin
- Cytokines
These all activate the coagulation cascade
Chemotherapeutic agents can also cause endothelial injury
Marantic Endocarditis caused by cancer can also cause thrombosis (This is inflammation of a heart valve, not caused by infection)

Question 10

What is an embolus?

Answer 10

A thrombus that has been mobilised into the vasculature, to a point where it gets trapped

Question 11

What is the most common path of an embolus?

Answer 11

Forms in the deep veins of the calf
Iliac veins
Inferior vena cava
Right atrium
Right ventricle
Pulmonary arteries - causing pulmonary embolism

Question 12

What is the visual sign of a pulmonary embolism on a chest X-ray?

Answer 12

A wedge (Thin triangle) shaped infarction

Question 13

What is ischaemia?

Answer 13

Insufficient blood supply

Question 14

What is infarction?

Answer 14

Death of tissue as a result of ischaemia

Question 15

What are some other common types of embolism?

Answer 15

Air embolism
The Bends
Amniotic Fluid embolism
Fat embolism
Tumour embolism
Septic embolism

Question 16

What is an air embolism?

Answer 16

Occlusion of a vessel by a significant amount of air in the blood

Question 17

How much air is required in injection to cause an air embolism?

Answer 17

Around 100ml of air

Question 18

What is the Bends?

Answer 18

A condition present usually in divers
It occurs as divers breath in air at very high pressures, which results in a large amount of dissolved gas (Nitrogen) in the blood
When the pressure reduces, nitrogen bubbles out of solution and can occlude the vessel

Question 19

What occurs in an amniotic fluid embolism?

Answer 19

This is a rare complication of child birth, present in 1/40,000 births
It is the 5th most common cause of maternal mortality
It is caused by a tear in the placenta or uterine vessels, with a secondary infusion of amniotic fluid or foetal matter
Foetal squamous cells and hair can be found in the pulmonary vessels

Question 20

What occurs in a fat embolism?

Answer 20

Fat and bone marrow leak into the blood vessels after a large skeletal injury
It occurs in 90% of significant injuries but only 10% of these show symptoms
It has a delayed onset of 1-3 days after the injury, with a distinct clinical syndrome

Question 21

What occurs in a tumour embolism?

Answer 21

Tumours (Especially mucinous tumours) are thrombogenic and can fall apart easily
This means that they are more likely to cause coagulation and thrombosis, which can then embolism

Question 22

What occurs in a septic embolism?

Answer 22

Specific intravascular infections cause thrombus formation
These infections include:
- Mycotic aneurysms
- Infective endocarditis

Question 23

What are splinter haemorrhages?

Answer 23

Small haemorrhages under the fingernails, caused by an embolism