Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cardio Exam 2 > 17 - Peripheral Arterial Disease > Flashcards

17 - Peripheral Arterial Disease Flashcards

1
Q

Define peripheral artery disease

A
  • Clinical disorder which consists of stenosis of the aorta or arteries in the limbs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the leading cause of PAD in patients over 40?

A

Atherosclerosis ***

KNOW THIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are other causes of PAD?

A
  • Thrombosis
  • Embolism
  • Vasculitis
  • Fibromuscular dysplasia
  • Entrapment
  • Cystic adventitial disease
  • Trauma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do we diagnose PAD for epidemiology?

A

Ankle-brachial index (ABI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the prevalence of PAD?

A
  • 6% in persons 40 years and older
  • 5% to 20% in those 65 years and older.
  • Highest prevalence in 60s and 70s
  • Highest prevalence with diabetes, smoking, hyperlipidemia, hypertension and renal insufficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What percent of PAD is symptomatic

A

Only 10-30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the modifiable risk factors for atherosclerosis?

A
  • Diabetes – endothelial cell dysfunction, inflammation
  • Hypertension – increased shear stress = ↓NO, ↑ inflammation, endothelial remodeling
  • ***Tobacco exposure – vasoconstriction, pro-inflammatory substances
  • Obesity – pro-inflammatory state
  • Hyperlipidemia – High LDL, low HDL, small dense LDL particles, hypertriglyceridemia
  • CKD

You NEED to get them to quit smoking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the non-modifiable risk factors for atherosclerosis?

A
  • Male
  • Age
  • Race (African American)
  • Family history of vascular disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pathophysiology of PAD

A
  • Disease of inflammation
  • Leukocytes, C-reactive protein and monocytes correlate with PAD
  • Serum bilirubin (endogenous antioxidant) associated with reduced PAD prevalence
  • Balance of circulatory supply and demand of oxygen & nutrient to skeletal muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the importance of balancing circulatory supply and demand of oxygen

A
  • Intermittent claudication - oxygen demand of skeletal muscle during effort exceeds the blood’s oxygen supply
  • Activation of local sensory receptors by accumulation of lactate or other metabolites.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the major factor regulating blood flow through an artery

A

Flow through an artery is directly related to perfusion pressure and inversely related to vascular resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe what happens as a stenotic lesion increases

A
  • As the severity of a stenotic lesion increases, flow becomes progressively reduced.
  • BP gradient exists at rest if the stenosis reduces the diameter of the lumen by more than 50% because as distorted flow develops, kinetic energy is lost.
  • As flow through a stenosis increases, distal perfusion pressure drops
  • Adenosine, nitric oxide, potassium, and hydrogen ion accumulate and vasodilation of peripheral vessels occur
  • IM pressure rise during exercise and may exceed arterial pressure distal to occlusion and halt blood flow
  • Collateral blood vessels usually suffice at rest but not during exercise
  • Abnormalities in microcirculation also contribute
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The hallmark of nearly all diabetic complications is…

A

ENDOTHELIAL DYSFUNCTION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Chronic metabolic changes lead to…

A
  • Vasoconstriction
  • Chronic inflammation
  • Tendency towards thrombosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe vasoconstriction in diabetic vascular disease

A
  • Autonomic dysfunction

- Decreased vasodilatory (NO, prostacyclin) and increased vasoconstrictive (prostanoids) cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe chronic inflammation in diabetic vascular disease

A
  • Free radicals, oxidative stress

- Increased expression of leukocyte adhesion molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe tendency towards thrombosis in diabetic vascular disease

A
  • Increased coagulation factor production

- Increased platelet aggregation (elevated GP IIb/IIIa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the risk of vascular disease in patients with chornic kidney disease

A
  • Patients with CKD at increased risk for PAD
  • Essentially ossification of arteries will occur
  • May have significant stenosis without evidence of plaque on angiography
  • Harder to treat ossification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the cardinal symptom of PAD?

A
  • Claudication (10-30%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe claudication

A
  • Pain, ache, sense of fatigue, or discomfort occurs with exercise and resolves with rest.
  • Location of symptoms is related to the site of most proximal stenosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the location of stenosis with the location of claudication pain

A

Site of pain: atery stenosed

  • Buttock/hip/thigh: Aorta/iliac
  • Calf: femoral/popliteal (consumes more oxygen during walking than other muscles —> most frequent symptoms)
  • Ankle/foot: tibial/peroneal
  • Shoulder: subclavian
  • Biceps: axillary
  • Forearm: brachial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is another clinical feature of PAD?

A

Critical limb ischemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe critical limb ischemia

A

Critical limb ischemia

  • Pain or paresthesias in foot or toes
  • Worsens with leg elevation and improves with dependency
  • Skin is very sensitive (weight of bedclothes/sheets elicits pain)
  • Dangle legs on edge of bed to alleviate discomfort
  • Diabetic neuropathy: little or no pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the other clinical features?

A 
Asymptomatic – 20-50%
Atypical leg pain – 40-50%
Critical limb ischemia – 1-2%
Walking impairment
Ischemic rest pain
Non-healing ischemic ulcers
25
Q

What are the physical findings of PAD?

A

Decreased or absent pulses distal to obstruction
Bruits over narrowed artery
Muscle atrophy

26
Q

What will you see in addition to this in more severe disease?

A 
More severe disease…
Hair loss
Thickened nails
Smooth and shiny skin
Reduced skin temperature
Pallor or cyanosis
27
Q

What is a risk of critical limb ischemia?

A

Ulcers or gangrene

28
Q

How do you non-invasively test for PAD?

A
  • Usually H&P are sufficient to establish diagnosis
  • Segmental Pressure Measurement
  • Ankel brachial index
  • Treadmill exercise protocol
  • Pulse volume recording
  • Continuse pulse with wave doppler
29
Q

How do you do a segmental pressure measurement?

A

Measure SBP at different upper and lower extremities segments
In iliac and femoral arteries a 70-90% decrease in cross-sectional area will cause a resting pressure gradient sufficient to decrease SBP distal to the stenosis.

30
Q

How do you determine if stenosis is present?

A

Stenosis is present if:
BP gradient >20 mmHg between cuffs in LE
BP gradient of >10 mmHg in UE

31
Q

How can you invasively test for PAD?

A

Contrast Angiography

  • Gold standard for diagnosis
  • Catheter is placed into a selected artery in both legs
  • Contrast is injected into vessels under fluoroscopy
  • Contrast injected form iliacs to tibials
32
Q

What are the advantages of contrast angiography?

A
  • Allows identification & quantification of lesions and assessment of inflow and outflow
  • Endovascular therapy and stenting can occur at the same time as the diagnostic exam
33
Q

What are the disadvantages of contrast angiography?

A
  • Invasive, higher complication rate than non-invasive

- $$$, time-consuming, requires sedation/recovery

34
Q

Describe magnetic resonance angiography

A
  • Gadolinium enhanced
  • Sensitivity 94.7%
  • Specificity 95.6%
  • Utility: symptomatic patients to assist in decision making before endovascular and surgical intervention or in patients at risk for renal, allergic, or other complications during conventional angiography.
35
Q

Describe computed tomographic angiography

A
  • Sensitivity 95%
  • Specificity 96%
  • Can be used in patients with stents, metal clips, and pacemakers
  • Requires radiocontrast material and ionizing radiation.
36
Q

What are the goals of treatment for PAD?

A
  • Reduce cardiovascular morbidity and mortality
  • Improve quality of life
  • Decreasing symptoms claudication
  • Eliminating rest pain
  • Preserving limb viability
  • Reduce risk for adverse cardiovascular events: MI, stroke, death
37
Q

How ca you reduce risk factors in the treatment of PAD?

A
  • QUIT SMOKING ***
  • Control blood sugar
  • Lose weight
  • Control HTN
  • Control hyperlipidemia
  • Rehab (supervised_ exercise training
38
Q

How do you treat intermittent claudication?

A

Supportive measures

  • Foot care: clean, moisturized, well fitting and protective shoes
  • Elastic support hose should be avoided
  • In critical limb ischemia: shock block under the HOB with a canopy over feet
  • Exercise regularly and at progressively more strenuous levels
  • Beneficial effect of supervised exercise training on walking performance in patients with claudication often is similar to or greater than that realized after a revascularization procedure.
39
Q

What type of patients with PAD should be on antiplatelet medication?

A
  • All patients with symptomatic PAD
  • All patients with intermittent claudication + risk factors
  • All patients with previous revascularization
  • May be useful for asymptomatic patients with ABI
40
Q

What is recommended for aspirin use for antiplatelet therapy?

A

ASA – 75mg-325mg daily dosing

Recommended to reduce risk of MI, CVA, and vascular death in individuals with symptomatic PAD

41
Q

What is recommended for clopidogrel for antiplatelet therapy?

A

Clopidogrel

  • Safe and effective alternative to ASA
  • May be used in addition to ASA in patients with severe PAD or those with progression despite ASA therapy
42
Q

What is recommended for anti-claudication medication?

A
  • Cilostazol

- Pentoxifylline

43
Q

Describe cilostazol

A

Cilostazol 100mg PO BID

  • Phosphodiesterase (PDE) inhibitor – non-homogenous vasodilation (femoral beds»others)
  • Reversibly inhibits platelet aggregation
  • Improves symptoms and walking distance (40-60%)
44
Q

Describe pentoxifyline

A

Pentoxifylline 400mg PO TID

  • Similar mechanism, though less well-defined
  • Second-line alternative to cilostazol
45
Q

Which therapies are ineffective in treating PAD?

A

Documented lack of efficacy:

  • Oral prostaglandins – beraprost, iloprost
  • Vitamin E
  • Chelation therapy

Marginal or insufficient evidence

  • L-arginine supplementation
  • L-carnitine supplementation
  • Gingko biloba
46
Q

What are the three surgical interventions for PAD?

A

Endovascular
Open bypass
Amputation

47
Q

What is the indication for percutaneous transluminal angioplasty (PTA) and stenting?

A

Indications:

  • Lifestyle-limiting disability due to claudication AND
  • Inadequate response to medical therapy AND
  • Reasonable likelihood of improvement with therapy
48
Q

When is PTA preferred?

A
  • Preferred first line therapy for iliac to fem/pop lesions
    90–95% of iliac PTAs are initially successful
  • 3-year patency >75%
49
Q

When is stent placement preferred?

A
  • Primary therapy in iliac stenosis/occlusion
  • Increased potency than PTA
  • Femoral-popliteal PTA and stenting 80% initially successful
  • 60% 3-year patency rates
50
Q

What is acute limb ischemia?

A

Sudden decrease in limb perfusion that causes a potential threat to limb viability

51
Q

What are the 6 Ps of acute limb ischemia?

A
  • Paresthesia
  • Pain
  • Pallor
  • Pulselessness
  • Poikilothermia – inability to regulate temperature
  • Paralysis – later stage – a very bad sign (limb usually not viable)
52
Q

How do you manage acute limb ischemia?

A

Requires prompt intervention with:

- Catheter directed thrombolysis (ALI

53
Q

How common is amputation?

A
  • 10% of patients with claudication progress to critical limb ischemia within 5 years
  • 20-30% of patients with critical limb ischemia go on to require major amputation
54
Q

What are the indications for amputation?

A

Indications

  • Extensive skin and tissue loss (especially on weight-bearing surfaces)
  • Major infection (sepsis)
  • Rest pain not controlled with all other measures
  • Uncorrectable flexion contracture
  • Paresis of the extremity
  • Poor life expectancy without intervention
55
Q

What is the overall mortality in post-amputation patients?

A

Overall mortality in post-amputation patients

  • Post-op – 5-20%
  • 2 year – 25-30%
  • 5 year – 50-75%
56
Q

What are the morbidities that occur with amputation?

A

Pain
Disability
Need for further surgery, amputation

57
Q

Describe the progression of complications and morbitidies

A

Complications/morbidity - above-knee&raquo_space; below-knee&raquo_space; below-ankle

58
Q

What are the key points of emphasis?

A
  • Atherosclerosis is a SYSTEMIC disease with REGIONAL preference
  • Atherosclerosis is in all the arteries
  • Peripheral arterial disease presents in a variety of ways from asymptomatic to acute life threatening events
  • Treatment of PAD involves lifestyle changes, medical therapy, and surgical intervention

Cardio Exam 2 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions