Peripheral Vascular Disease and Pulmonary Embolism

Question 1

Clinical Outline PE Case: - 71 yr, BMI = 30 (classified as obese) - Train 7 hour trip, no drink, to stay with friend for a week - 2 days later sudden SOB At hospital: - Swollen, tender leg - Tachycardia (120) - ‘Normal’ chest exam

What are the clinical features of Well’s criteria here?

Answer 1

Clinical features of Well’s:

• Leg swelling, tender
• Tachycardia

Question 2

What is Well’s Criteria?

Answer 2

A risk stratification score and clinical decision rule to estimate the probability for acute pulmonary embolism (PE) in patients in which history and examination suggests acute PE is a diagnostic possibility.

Question 3

If a PE is supsected, what medical test is required for diagnoses?

Answer 3

CTPA - CT pulmonary angiogram

Question 4

What happens during a CTPA?

Answer 4

Dye injected into vessels which travels to pulmonary arteries –> a CT pulmonary angiogram takes pictures of the blood vessels that run from the heart to the lungs (the pulmonary arteries).

Question 5

What would a PE look like in a CTPA?

Answer 5

A normal CTPA scan will show the contrast filling the pulmonary vessels, appearing as bright white. Any mass filling defects, such as an embolus, will appear dark in place of the contrast, filling/blocking the space where blood should be flowing into the lungs.

Question 6

What is the management for PE?

Answer 6

• Low molecular weight heparin
• Consideration for thrombolysis and anticoagulation

Question 7

What is a pulmonary embolism?

Answer 7

a blocked blood vessel in your lungs

Question 8

What is the pathology underlying swollen, tender leg?

Answer 8

• Outflow blocked from lower limb
• Increased hydrostatic pressure
  
  • Caused fluid to move out into extracellular space
• Collateral blood flow
  
  • Cause reddening and swelling

Question 9

What is the pathology underlying tachycardia?

Answer 9

• Increased workload due to narrowing of vessels
• Pump (RV) working harder due to resistance past emboli

Question 10

Clincal Outline: Peripheral Arterial Disease / Peripheral Vascular Disease

• 71 yr, BMI = 30, smoked all life
• Pain in left leg when walks to shops
• Sees GP: reduced ankle brachial index (i.e. ankle pressure lower than should be)

What does a reduced ankle brachial index imply?

Answer 10

There is a problem with peripheral arterial system

Question 11

Initial recommended treatment for PAD?

Answer 11

Exercise and aspirin

Question 12

If the pain in leg continous and progresses in PAD case, what should be recommended?

Answer 12

MRA (magnetic resonance angiogram) –> this is a type of MRI that looks specifically at the body’s blood vessels

Question 13

How does the PAD patient’s lifestyle predispose him to atherosclerosis?

Answer 13

Obese, smoker, age

Predisposed to atherosclerosis –> response to injury hypothesis

This atheroma coupled with Virchow’s Triad (and thrombosis) puts patient at risk

Question 14

What is peripheral vascular/arterial disease?

Answer 14

A common condition where a build-up of fatty deposits in the arteries restricts blood supply to leg muscles.

Question 15

If left untreated, what can PAD lead to?

Answer 15

Organ damage and loss of fingers, toes, or limbs,

Question 16

How does atheroma combined with thrombsis lead to tissue damage?

Answer 16

Can be acute or chronic

Acute:

• Plaque or thrombus causes narrow lumen, reduced blood flow, ischaemia, tissue damage/death

Chronic:

• Gradual rupture and atherosclerosis formation, narrows lumen, reduced blood flow, ischaemia, tissue damage/death

Question 17

How is age a predisposing factor?

Answer 17

Within increasing age, progressively higher chance of endothelial injury and dysfunction leading to more foci and greater degree of atherosclerotic damage

Also lower activity levels, higher chances of hypertension (loss of elasticity of vessels), diabetes and other comorbidities.

Question 18

How is obesity a predisposing factor?

Answer 18

Increased chances of DM, hypertension and raised cholesterol, all factors which are known to promote formation of atherosclerosis

Question 19

What are predisposing factors for a DVT?

Answer 19

are over 60

are overweight

smoke

have had DVT before

take the contraceptive pill or HRT

have cancer or heart failure

have varicose veins

are staying in or recently left hospital – especially if you cannot move around much (like after an operation)

are confined to bed

go on a long journey (more than 3 hours) by plane, car or train

are pregnant or if you’ve had a baby in the previous 6 weeks

are dehydrated

Question 20

Treatment for a DVT?

Answer 20

You may have an injection of an anticoagulant (blood thinning) medicine called heparin while you’re waiting for an ultrasound scan to tell if you have a DVT.

After DVT is diagnosed, the main treatment is tablets of an anticoagulant medicine, such as warfarin and rivaroxaban. You will probably take the tablets for at least 3 months.

Question 21

Symptoms of PAD?

Answer 21

Due to loss of nutrients going to periphery:

hair loss on your legs and feet.

numbness or weakness in the legs.

brittle, slow-growing toenails.

ulcers (open sores) on your feet and legs, which do not heal.

changing skin colour on your legs, such as turning pale or blue.

shiny skin.

in men, erectile dysfunction.

Question 22

What can PAD lead to in more severe cases?

Answer 22

Critical Limb ischaemia:

Severe pain in lower limbs at rest
Skin pale, shiny, smooth and dry
Wounds and ulcers (open sores) – non-healing
Loss of muscle mass in legs
Skin on toes or lower limbs –cold, numb, turning red and then black, and/or beginning to swell and produce smelly pus, causing severe pain (gangrene)

Question 23

Relationship of blockage to peripheral tissues in vein? Artery?

Answer 23

Vein - blockage occurs after

Artery - blockage occurs before

Question 24

Effect on peripheral tissues of venous vs arterial blockage?

Answer 24

Venous - swelling, darkening, tender

Arterial - atrophy, pallor, pain

Question 25

Tissue found distal to venous blockage? Arterial blockage?

Answer 25

Venous - lungs

Arterial - all other tissues (esp peripheries)

Question 26

Adaptation of vessels in venous blockage? In arterial blockage?

Answer 26

Venous - collaterals

Arterial - collaterals

Question 27

What is an ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) ?

Answer 27

The ratio of the blood pressure at the ankle to the blood pressure in the upper arm. Compared to the arm, lower blood pressure in the leg suggests blocked arteries due to peripheral artery disease (PAD).