Patho & Treatment - Peripheral Arterial Disease

Question 1

What type of arteries are atheromas more likely to form in?

Answer 1

Large, high flow arteries

Question 2

What are the main preventable risk factors driving the development of peripheral artery disease?

Answer 2

Smoking

Diabetes

Question 3

What are the various names given to peripheral arterial disease (PAD)?

Answer 3

Peripheral artery atherosclerosis

Peripheral artery occlusive disease (PAOD)

Question 4

What is an atheroma?

Answer 4

A collection of lipids, cholesterol, fibroblasts and S.mm cells & collagen fibres – lying under the intima & projecting into the lumen within peripheral circulation

Question 5

What occurs within the artery when an atheroma is there?

Answer 5

Endothelial dysfunction (NO) - limited vasodilation
Vessel stenosis & tissue ischaemia
Possible thrombus formation

Question 6

What condition are you 40-60% more likely to have if you already have PAD?

Answer 6

Cerebral artery disease, atherosclerotic disease of the coronary and cerebral circulation

Question 7

Name the risk factors for PAD

Answer 7

1. Dyslipidaemia
2. Sedentary lifestyle
3. Hypertension
4. Age (20% of >65 year olds)
5. Gender - males have higher risk of PAD as in the UK more men smoke than women
6. Diabetes - the main driving force behind PAD
7. Smoking

Question 8

How does smoking impact the integrity of the blood vessels?

Answer 8

Smoking activates the SNS i.e. nicotine activates nicotinic receptors on the adrenal medulla causing production and release of catecholamine

• This causes VC of arterioles - increases TPR - increasing blood pressure - increasing shearing forces and causing endothelial damage

Endothelial damage is the starting point of atheroma. The nicotine acts directly on the endothelial cells causing damage & it damages beta cells in islets of Langerhan in the pancreas

• If enough beta cells are damaged, hyperglycaemia occurs which then causes endothelial damage through glucose attachment to lipids and protein in the endothelial wall (i.e. glycosylation). This results in the formation of advanced glycolytic end products which precipitate an inflammatory response & causing more endothelial damage

Question 9

What is the impact of smoking on the risk of getting PAD?

Answer 9

Smokers develop PAD 10 years earlier than non-smokers
Smokers are more likely to progress to amputation
Smoking is a greater risk factor for development of PAD than it is for developing CHD

Question 10

How does sudden blood vessel occlusion occur?

Answer 10

A thrombus sitting on top of a pre-exisiting ruptured atheroma
This will result in an AMI

Question 11

How is glycaemic control in diabetes measured longterm?

Answer 11

The % of glycosyated haemoglobin (Hb1Ac)

Question 12

How does type 2 diabetes potentially cause PAD?

Answer 12

• Type 2 diabetes is associated with high levels of VAT
• VAT occurs due to poor diet & lack of exercise
• VAT secretes inflammatory cytokines which cause endothelial damage
• Hyperglycaemia caused when there is insulin resistance, hyperglycaemia is worsened by beta cell dysfunction. Hyperglycaemia causes endothelial cell damage by AGEs
• Both AGEs and cytokines cause a pro-inflammatory state
• Lipolysis of adipocytes occurs causing the release of FFAs as an end product. Resistin helps with uptake of FFAs to be taken up by liver & converted to LDLs which cause atheroma development

Question 13

How does type 1 diabetes potentially cause PAD?

Answer 13

• Type 1 is driven by beta cell functioning - causing hyperglycaemia and endothelial damage
• A lack of insulin secondary to beta cell dysfunction causes breakdown of FFAs which are taken up (without the assistance of resistin) converted to LDLs by liver which causes atheroma formation

Question 14

How is PAD classified in terms of disease progression?

Answer 14

Non-critical limb ischaemia

Critical limb ischaemia

Question 15

What is the main symptom of non-critical limb ischaemia?

Answer 15

intermittent claudication (i.e. pain with activity)

Question 16

What is the main symptom of critical limb ischaemia?

Answer 16

Intermittent claudication accompanied by one of the following symptoms;

1. Rest pain
2. Tissue loss or ulceration
3. Tissue necrosis/gangrene

Question 17

Describe the different levels in the Fontaine Classification of PAD

Answer 17

I. “Subclinical” – subtle changes e.g paraesthesia/anaesthesia – cold extremities – diminished pulses & restless leg syndrome

II. Characterised by intermittent claudication (treadmill test) (depending on how far they can walk)
IIa. Intermittent Claudication > 200m
IIb. Intermittent Claudication < 200m

III. Rest pain (initially at night)

IV. Ischaemic ulcers or gangrene

Question 18

Describe thermal imaging used to diagnose PAD?

Answer 18

identifies warm and cold areas of the leg. Warm = i.e. red areas where the blood can perfuse. Cold = purple, dark green, yellow - blood is not perfusing here and there may be an atheroma in that artery

Question 19

Describe the ankle-brachial pressure index (ABPi)

Answer 19

Its used to diagnose PAD
Systolic pressure is taken at brachial artery and compared to systolic pressure taken at posterior tibial or the dorsalis pedis artery

Question 20

Name all the ways PAD can be measured

Answer 20

Fontaine classifcation
Thermal imaging
Ankle brachial pressure index (ABPi)
Doppler & pulse volume recordings
Angiogram

Question 21

Name the ABPi score for each clinical status

Answer 21

Symptom free: 1
Intermittent claudication: 0.95 - 0.5
Rest pain: 0.5 - 0.3
Gangrene and ulceration: <0.2

Question 22

Name the symptoms of lower limb ischaemia

Answer 22

1. Intermittent claudication - excruciating muscle pain causing a mismatch between O2 demand and actual blood flow. Is evident when patient undertakes physical activity
2. Diminished /absent pulse - atheroma has ruptured, blood flow has been interrupted and a thrombus has formed
3. Atrophic skin changes - poor nutrition to skin as there is inadequate arterial blood supply. Dry, flaky, shiny skin
4. Skin colouration
5. Elevation pallor & dependent rubor (redness) - pallor when foot is horizontal and gets worse when foot is raised.
6. Sensory disturbances - becomes worse as the disease progresses
7. Cold extremities
8. Sarcopenia

Question 23

What is the arch of pain in intermittent claudication?

Where is pain located typically in intermittent claudication?

Answer 23

Pain subsides after physical activity has ceased. When the atheroma gets larger the ischaemic threshold is reduced
Femero-popliteal (calves) is the most common artery

Question 24

What is the outcome of intermittent claudication?

Answer 24

40% improve over 2 years
40% remain unchanged
20% will deteriorate & develop critical limb ischaemia
2-8% need amputation

Question 25

How does sarcopenia occur in PAD?

Answer 25

Occurs due to sedentary behaviour causing disuse atrophy (due to the pain associated with intermittent claudication will cause the patient to reduce their levels of physical activity) Loss of muscle fibres driven by age & death of anterior horn cells Inflammatory processes (reactive oxygen species and inflammatory cytokines) drive muscle atrophy and sarcopenia

Question 26

What are the NICE guidelines for management of non-critical limb claudication?

Answer 26

1. Diet 2. Smoking cessation 3. Control hypertension 4. Regulate HLD:LDL (statins) 5. Regulate blood glucose & HB1AC levels 6. Aspirin 7. Peripheral vasodilators 8. Supervised exercise to include walk programme

Question 27

Is weight-bearing or non-weight bearing exercises best for improving claudication in PAD?

Answer 27

Better to do weight-bearing exercises however if patients are very ischaemic then you should start them on non-weight bearing exercises With PAD patients you should push them into ischaemic pain. In CVD patients you should never push them into pain

Question 28

Should exercise be supervised or unsupervised?

Answer 28

Supervised exercise programmes produce greater increase in distance of pain free walking (before intermittent claudication comes on)

Question 29

What is the prescription of exercise per week and what would it consist of?

Answer 29

``` Supervised exercise programme 2hrs / week For 3 months Aerobic exercise - non-weight bearing like rower, bike. Could do weight-bearing also - such as stepper/stair climber Strength/flexibility ``` and patients should do independent exercise such as walking in moderate intensity pain (4/5 on the pain scale) limits outside of their exercise plan. Walk for a minimum of 3-5 minutes. They should take a break (they should record duration & frequency of breaks) when they go into moderate intensity pain - Repeat for 30min if possible Increase incline - ensure they are walking for 3 minutes Then increase speed

Question 30

What outcome measure would you use for PAD patients?

Answer 30

``` 1. Claudication Scale - 5-point pain scale 1= no pain 2= pain/discomfort begins 3= mild pain or discomfort 4= moderate pain 5= severe pain ``` 2. Or Borg CR-10 Scale (not the RPE Scale)

Question 31

What physiological changes are likely to occur in a walk training programme to influence pain characteristics (freq & intensity) function?

Answer 31

1. Improved blood supply through angiogenesis | 2. Classic skeletal muscle type I training effect - improved fibre aerobic efficiency

Question 32

What causes angiogenesis to occur as a consequence to an exercise programme for PAD patients?

Answer 32

When tissues are ischaemic they release the following (which act on the arterial wall to promote the formation and development of angiogenesis) - Vascular endothelial growth factor (VEGF) - Fibroblastic growth factor (FGF) - Platelet derived growth factors (PDGF) - Tumour necrosis factor (TNF)

Question 33

Does exercise ALWAYS improve intermittent claudication?

Answer 33

Sometimes despite being on vasodilator drugs, adhering to the exercise programme and improving diet etc intermittent claudication does not improve and it interferes with QoL or worsens symptoms. If this occurs vascular surgery is performed

Question 34

What condition is more likely to occur if a patient has critical limb ischaemia (CLI)?

Answer 34

A CVD - AMI or a stroke

Question 35

Define CLI

Answer 35

``` Chronic ischaemia with at least one of: • - rest pain - often worse at night • - ulceration • - gangrene in one or both legs secondary to objectively proven occlusive disease. ```

Question 36

Why is rest pain worse at night?

Answer 36

Core temperature drops and due to inactivity cause a fall in metabolic demand which causes a drop in HR & BP BP is the driving force behind perfusion compounding arterial insufficiency They try to use gravity to help perfuse their lower limbs

Question 37

What is used to treat rest pain?

Answer 37

Opiates - morphine Lumbar sympathectomy - identifying the autonomic nerve supplying the arteriole and severing it which removes the vasomotor control over the arteriole (reduces VC and causes arteries to VD). Very high risk procedure due to spine Angioplasty or by-pass grafting Amputation Lifestyle modification

Question 38

Describe where arterial ulcers usually occur and some of the symptoms and treatments used

Answer 38

``` Dorsum of foot or in pre-tibial area Irregular in shape Very painful Usually deep Inflammation around the wound ``` Necrotic tissue is excised Broad spectrum antibiotics are used, may need vascular reconstruction or skin grafting

Question 39

What are the NICE guidelines for management of critical limb ischaemia?

Answer 39

Continued lifestyle modifiation to prevent AMI and stroke Angelgesia Angioplasty (+stent) By-pass grafting Amputation Cardiovascular drugs - anti-platelets (aspirin), statins to prevent thrombus formation if an atheroma ruptures

Question 40

What treatment would you give someone who has gangrene/necrosis?

Answer 40

Amputation

Question 41

What surgery is available for critical limb ischaemia?

Answer 41

Angioplasty | By-pass grafting

Question 42

At what point is surgery offered for patients with PAD?

Answer 42

When patient has critical limb ischaemia so their condition doesn't progress to tissue death

Question 43

Describe the procedures available to remove a local atheroma in arterial insufficiency?

Answer 43

Directional or laser atherectomy Balloon angioplasty +/- stent insertion - Often called percutaneous transluminal angioplasty - a peripheral PCI

Question 44

Describe the procedures available to remove multiple atheromas in arterial insufficiency?

Answer 44

(same procedure used for coronary by-pass surgery) By-pass grafting - saphenous vein is most often used, femoral - popliteal vein is used also (both used as they are such long veins) - the vein is inverted (turn upside down) so it can function as an artery instead of a vein

Question 45

What type of medication would patients be on?

Answer 45

Anti-platelets e.g. clopidogrel, prasugrel and ticagrelor Statins - mandatory for atheroma-based diseases e.g. simvastatin, avrostatin, fluvastatin Anti-hypertensives - beta-blockers i.e. olol - metaprolol, atenolol, propranolol Anti-hyperglycaemics - sulfonyureases i.e. -ide - glimepriide, glipizide, glyburide or metformin which is a biguanide (lowers production of glucose in the liver)

Question 46

What does post-graft physiotherapy look like?

Answer 46

Mobilise patient Aerobic and strength exercise Education - behavioural modifications

Question 47

Name the reasons why a limb may be amputated

Answer 47

Malignancies Trauma Complications of diabetes mellitus Atherosclerotic cardiovascular disease

Question 48

Name some possible co-morbidites an elderly amputee may have

Answer 48

hypertension, diabetes, peripheral neuropathy, reduced vision, peripheral vascular disease in the intact limb, deconditioned

Question 49

What are the recommended 2 components of physical activity for disabled adults?

Answer 49

- 120-180 min a week of moderate to vigorous intensity exercise along with - 2 sets of strength and balance exercises X2/week

Question 50

Do amputees regularly engage in physical activity?

Answer 50

Majority do not undertake enough physical activity to be classified as sufficiently active

Question 51

When an amputee exercises what is the effect on their body (specific lung and heart measurements) ?

Answer 51

Activities are much less efficient Cardiovascular demands are higher than in non-amputees Lower aerobic capacity and lower VO2 peak Metabolic costs of walking is more demanding on VO2 and HR --The higher the amputation in the leg the greater the additional energy expenditure is

Question 52

What is the explanation for the increased metabolic costs of walking in amputees?

Answer 52

Vascular amputations often associated with a greater metabolic cost than traumatic amputations, even when the level of amputation is the same. Elevated metabolic cost of walking may be related to the number, type, and magnitude of compensations to control balance and propulsion e.g. the hip having to control the amputated knee, hip hiking

Question 53

What are the specific benefits of aerobic training in amputees?

Answer 53

Improvement in the ventilatory response to exercise & the ventilatory threshold Increased maximal oxygen consumption (mean of 20%) Improved psychosocial well-being & self-efficacy Improved insulin sensitivity & reduced risk of prediabetes or diabetes Decrease in metabolic costs during ambulation Decreased blood platelet adhesiveness, fibrinogen, & blood viscosity & increased fibrinolysis Increased vagal tone & decreased adrenergic activity, resulting in improved heart rate variability

Question 54

What are the specific benefits of resistance training in amputees?

Answer 54

Reduced muscle atrophy in the amputated & intact limbs Increased balance & stability in the intact limb Increased hip flexor strength in the amputated limb will enable ground clearance of the prothesis during the swing-phase of the gait cycle Increased upper body strength enables self-care activities, walking with crutches, transfers & self- propelling in a wheel-chair.

Question 55

What are the specific benefits of flexibility training in amputees?

Answer 55

(With a prosthesis) it will reduce the risk of developing hip & knee contractures Increase gastrocnemius & soleus ROM of the intact limb to reduce the loss of dorsiflexion.

Question 56

What are the overall health benefits of physical activity in amputees?

Answer 56

Reduces; 1. Type 2 diabetes 2. Colon cancer 3. Breast cancer 4. All-cause mortality 5. Cardiovascular disease 6. Dementia 7. Hip fractures 8. Depression

Question 57

What are the aerobic FITT recommendations for individuals with lower limb amputation?

Answer 57

Frequency: 3-7 days/week Intensity: Moderate (40-50%HHR), vigorous (60-80% HRR) Time: 120-180 min moderate-vigorous intensity Type: Activities using large muscle groups - treadmill, bike, rowing, swimming

Question 58

What are some considerations for aerobic training in amputees with prosthesis?

Answer 58

Avoid high impact (stump) Lower the heart rate training zone by 10 bpm when doing arm ergometer Avoid treadmill in early stage to avoid falls Short bouts of 5-10min Ensure knee locking mechanism is released so the prosthesis at the knee can bend

Question 59

What are the strength/resistance training FITT recommendations for individuals with lower limb amputation?

Answer 59

F: A minimum of 2 non-consecutive days/week (preferably 3 days/week) I: Moderate - vigorous (60-80% of 1-RM) 8-10 exercises, 2-4 sets of 8-12 reps T: Resistance machines, bands, free weights, partial/full bodyweight

Question 60

What are some considerations for strength/resistance training in amputees with prosthesis?

Answer 60

- Use both open-chain and closed chain exercises (adapting open-chained in closed chain) - Lower-extremity regimen should include exercises for the surrounding hip muscles, especially hip abductor & hip extensor groups for pelvic stabilization - Shoulder stabilizers, adductors, and depressors, elbow extensors, wrist stabilizers, and hand-grasp strength are of prime importance for supporting the body for transfers and the use of walking aids

Question 61

What are the flexibility training FITT recommendations for individuals with lower limb amputation?

Answer 61

To increase ROM and decrease contractures F: 2-3 days/week I: Stretch to point of tightness/slight discomfort T: Hold static stretch 10-30 sec, 2-4 reps of each exercise. Totally 60 sec T: static, dynamic, PNF stretching

Question 62

What are the signs of ischaemia in a foot?

Answer 62

``` Poor quality skin and nails No blood or oxygen No hairs, skin dies Toes may auto-amputate Osteomyeslitis - bone damage - can occur and causes the patient to be unable to walk ```

Question 63

What occurs in wet gangrene?

Answer 63

Gas collects under the skin and foots needs to be urgently amputated

Question 64

Where does amputation usually occur?

Answer 64

``` Above knee - distal 1/3 of femur Through knee Below knee - proximal 1/3 of tibia/fibula Symes - from distal Forefoot - across the metatarsal bones ```