Atherosclerosis, Thrombosis, Embolism

Question 1

Define ‘thrombosis’

Answer 1

Formation of a mass (thrombus) from the constituents of blood within the vasculature during life

Question 2

How does a thrombus differ from a clot?

Answer 2

Thrombus must form during life in the body; clots can form when blood is extracted post-mortem

Question 3

What are the 3 components of Virchow’s triad?

Answer 3

Changes in blood flow
Changes in blood coagulability
Endothelial damage

Question 4

Give some examples of hypercoaguable aquired states

Answer 4

Myocardial infarction
Immobility
Cancer
Prosthesis
AF
Cardiomyopathy
Oral contraceptive use

Question 5

Arterial thrombi are red. True/False?

Answer 5

False

Question 6

Where do arterial thrombi often lodge?

Answer 6

Coronary, cerebral, femoral circulations

Question 7

Define ‘embolism’

Answer 7

Detached intravascular solid/liquid/gas mass carried distal to point of origin

Question 8

Venous emboli commonly infarct peripheral circulation. True/False?

Answer 8

False
Very rare (carried to pul circulation, more likely lodge there)

Question 9

Give examples of factors causing endothelial injury

Answer 9

Smoking
Hyperlipidaemia
Hypertension
Toxins
Infection

Question 10

Give examples of what happens due to endothelial dysfunction

Answer 10

Increased permeability

Macrophage + platelet adhesion and activation

Question 11

Once macrophages are activated on the endothelial surface, what do they generate?

Answer 11

Oxidative free radicals

Cytokines

Question 12

What do oxygen free radicals do to LDL?

Answer 12

Ingest and trap it within macrophages, forming foam cells/fatty streaks

Question 13

In a pre-test probability (PTP) score for DVT, the scoring does not apply in what situations?

Answer 13

If you have had a previous DVT

If you are pregnant

Question 14

A PTP score for DVT of 3 or more is high risk. True/False?

Answer 14

True

Question 15

D-dimer can both rule out and diagnose DVT. True/False?

Answer 15

False

Question 16

What is D-dimer?

Answer 16

A breakdown product of fibrin

Question 17

If D-dimer levels are low, a DVT is unlikely. True/False?

Answer 17

True

Question 18

If D-dimer levels are high, a DVT is very likely. True/False?

Answer 18

False

D-dimer levels are raised by many things (infection, MI, surgery)

Question 19

If your PTP score is low and D-dimers are low, a DVT can be excluded. True/False?

Answer 19

True

Question 20

If your PTP score is low and D-dimers elevated, what is the next investigation for diagnosing a DVT?

Answer 20

(Doppler) ultrasound

Question 21

If your PTP score is high and D-dimers low and US negative, DVT can be excluded. True/False?

Answer 21

True

Question 22

If your PTP score is high and D-dimers high but US negative, DVT can be excluded. True/False?

Answer 22

False

Repeat US before completely excluding DVT

Question 23

What is the mainstay of DVT treatment?

Answer 23

Anticoagulation (LMWH heparin, warfarin)

TED compression stockings

Question 24

What is phlegmasia dolens?

Answer 24

DVT causes obstruction of arterial flow due to back pressure created

Question 25

How is phlegmasia dolens usually treated?

Answer 25

IVC filter through femoral artery which prevents thrombus entering lungs

Question 26

What is the first line imaging modality of choice for PE?

Answer 26

V/Q scan

Question 27

What is the advantage of a caval filter for acute PE?

Answer 27

Prevents recurrence of PE in short term

Question 28

What is the drawback of a caval filter?

Answer 28

Increases risk of DVT - patients will require anticoagulation if long-term filter

Question 29

When is warfarin contraindicated?

Answer 29

Pregnancy | Increased haemorrhage risk (uncontrolled drug abuse, dementia etc.)