Peripheral Arterial Disease
Laura A. Petty
Definition
A.Peripheral arterial disease (PAD) is a circulatory disorder generally characterized by the buildup of plaque on the interior surface of arteries. These plaques harden and narrow the diameter of the arteries, which reduces the volume of blood circulating to internal organs and extremities. The arteries affected by PAD include all arteries in the body, with the exception of the cerebral and coronary arteries. The decreased circulation seen in PAD can also be caused by nonatherosclerotic conditions. Some of these conditions are arteritis, trauma, radiation damage, and fibromuscular dysplasia. Symptoms of PAD can occur in upper or lower extremities.
B.Classification of PAD:
1.Asymptomatic PAD:
a.No symptoms but the presence of risk factors or a new diagnosis of a common coexisting disease (coronary artery disease [CAD] or cerebrovascular disease) should prompt further evaluation.
2.Intermittent claudication (IC):
a.Discomfort with physical exertion that remits a few minutes after activity ceases.
3.Chronic limb ischemia:
a.Pain at rest and/or skin ulceration.
4.Acute limb ischemia:
a.Pain at rest with a pulseless extremity.
C.Other conditions contained within PAD:
1.Buerger’s disease (thromboangiitis obliterans): A disease manifested by inflammation, peripheral edema, and micro thrombi leading to gangrene of the hands and feet. Usually caused by tobacco abuse, and patients are thought to have a genetic predisposition to develop this condition.
2.Raynaud’s syndrome: A vasospastic disorder manifested by a response in the extremities to cold temperatures or stress where pallor, cyanosis, numbness, and/or pain are experienced
3.Leriche syndrome: The triad of claudication, absent or diminished femoral pulses, and erectile dysfunction.
Incidence
A.In 2012, the Vascular Disease Foundation estimated that 8 to 12 million adults in the United States had PAD. This correlates to between 12% and 20% of Americans older than 65 years of age.
B.PAD is more common in men than in women.
C.PAD is more common in patients of African and Hispanic descent.
Pathogenesis
A.PAD is most commonly precipitated by atherosclerosis. An atherosclerotic plaque develops in response to turbulent blood flow on the endothelial cells of the vessel wall. The plaque contains inflammatory cells and a thrombogenic lipid core that is covered by a fibrous cap. When the fibrous cap is disturbed, the lipid core can precipitate to development of a thrombus and lead to occlusion of the vessel.
Predisposing Factors
A.Smoking.
B.Diabetes.
C.Dyslipidemia.
D.Hypertension (HTN).
E.Obesity.
F.Age, increased occurrence after age 60.
Common Complaints
A.Pain with activity is commonly characterized as cramping and/or aching:
1.Upper extremity pain in the forearm, hand, and digits.
2.Lower extremity pain in the foot, calf, hip, thigh, and/or buttocks:
a.Foot pain is most common in tibial or peroneal artery stenosis.
b.Calf pain is most common with superficial femoral or popliteal artery stenosis.
c.Thigh pain is most common in aortoiliac and common femoral artery stenosis.
d.Hip and buttock pain are most common with aortoiliac arterial stenosis.
B.Pain at rest.
C.Calf weakness or fatigue.
D.Numbness or tingling.
E.Dizziness with upper extremity exertion.
F.Syncope with upper extremity exertion.
G.Extremity ulceration.
Other Signs and Symptoms
A.Decreased peripheral pulses.
B.Blanching of the affected limb with elevation.
C.Ulcerations or infection on distal aspects of extremities.
D.Erectile dysfunction.
Potential Complications
A.Nonhealing lower extremity ulcerations.
B.Infection.
C.Amputation.
D.Common coexisting diseases:
1.CAD; also known as coronary heart disease (CHD).
2.Cerebrovascular disease.
Subjective Data
A.Ask patient what activity brought about or preceded the episode or whether it occurs at rest. If ambulation was the precipitating factor, how far was the patient able to walk?
B.Have patient describe duration of pain and what time of day symptoms began.
C.Ask patient what alleviates his or her pain.
D.Ask patient whether any previous episodes have occurred.
E.Ask patient to list all medications, including over-the-counter (OTC) and herbal products currently being taken or recently stopped.
F.Ask patient to quantify his or her smoking history.
G.Ask patient if he or she has had a past medical history of an myocardial infarction (MI) or cerebrovascular accident (CVA).
H.If patient is male, ask if he has any history of impotence or erectile dysfunction.
Physical Examination
A.Patients presenting with acute limb ischemia should be quickly assessed for the need to call emergency services/911 for immediate transport to the hospital:
1.Symptoms of acute limb ischemia as evidenced by the six Ps—pain, pallor, paresthesia, paralysis, pulseness, and poikilothermia (the inability to maintain a constant core temperature).
B.Vital signs:
1.Check blood pressure (BP) in both upper extremities:
a.A difference in systolic blood pressure (SBP) of 10 mmHg or greater in upper extremities is associated with upper extremity PAD and cerebrovascular disease.
b.A difference in SBP of 15 mmHg or greater in upper extremities is associated with lower extremity PAD.
2.Check blood pressure (BP) in both lower extremities.
3.Document resting heart rate, respirations, height, and weight.
C.Inspect:
1.Perform a fundoscopic exam: Check for retinal vascular changes.
2.Inspect abdomen for a pulsating abdominal mass.
3.Inspect extremities. Note edema, pallor, and cyanosis. Note color of extremities in dependent and elevated positions.
4.Inspect distal skin, hair, and nails. Note any temperature discrepancies or trophic changes that are indicative of ischemia.
5.Assess lower extremities for any ulcerations or diffuse erythema.
6.Assess for Homans’ sign (i.e., calf pain with forced dorsiflexion).
7.Assess whether pain occurs when affected limb is elevated.
D.Palpate:
1.Palpate pulses, noting symmetry:
a.Bilateral upper extremities (brachial and radial).
b.Abdominal (aorta).
c.Bilateral groin (femoral).
d.Bilateral lower extremity pulses (popliteal, dorsalis pedis, and posterior tibialis).
2.Palpate capillary refill.
3.Perform an Allen test: Occlude the radial and ulnar arteries with the fist closed. Open the hand and then release one of the occluded arteries. Repeat but release the other artery. Each time, prompt capillary refill should occur.
4.Palpate neck for carotid bruits.
5.Palpate the abdominal aorta, noting any lateral pulsation, which is indicative of an aortic aneurysm.
E.Auscultate:
1.Auscultate heart: Assess rate, rhythm, heart sounds, murmur, and gallops.
2.Auscultate carotids, abdomen, and bilateral groin for bruits.
3.Auscultate lungs: Assess lung sounds, noting any sign of heart failure (HF).
Diagnostic Tests
A.Doppler ankle/brachial index (ABI):
1.Interpretation of ABI ratios:
a.1.00 to 1.29: Normal.
b.0.91 to 0.99: Borderline PAD.
c.0.41 to 0.90: Mild to moderate PAD.
d.0.00 to 0.40: Severe PAD.
B.Basic metabolic panel (BMP; including blood urea nitrogen [BUN], creatinine, sodium, and potassium).
C.Lipid profile.
D.C-reactive protein (CRP), homocysteine, D-dimer.
E.ECG (12 lead).
F.Doppler ultrasound.
G.Abdominal ultrasound.
H.Treadmill testing.
I.Computed tomographic angiography (CTA).
J.Magnetic resonance angiogram (MRA).
K.Arteriography, ordered and performed by surgeon.
Differential Diagnosis
A.PAD.
B.Venous stasis.
C.Venous obstruction/claudication.
D.Spinal stenosis.
E.Nerve root compression.
F.Arthritis of the hip.
G.Peripheral neuropathy.
H.Arteritis.
Plan
A.General interventions.
1.The goal of therapy is to improve the patient’s quality of life by reducing morbidity and prolonging survival.
B. 
See Section III: Patient Teaching Guide “Peripheral Arterial Disease“:
1.Encourage smoking cessation, weight loss, and exercise, if applicable.
2.Encourage strategies to better manage other chronic medical conditions that directly affect the progression of PAD, that is, diabetes, dyslipidemia, obesity, and HTN.
3.Proper foot care:
a.Instruct patient to wear proper-fitting shoes that protect the feet.
b.Inspect inside of shoes before donning.
c.Encourage patient to inspect feet daily for signs of trauma or infection.
d.Instruct patient to dry feet well, including between toes, after bathing.
C.Prevention:
1.Control other chronic medical conditions, that is, diabetes, dyslipidemia, HTN, and obesity.
D.Dietary management:
1.To manage dyslipidemia and HTN: Counsel patient on nutrition and low-fat, low-cholesterol, and low-sodium diet.
2.To manage diabetes: Counsel patient on diabetic diet and carbohydrate counting.
3.To manage infection related to PAD: Counsel patient on high-calorie, high-protein diet. Consider the addition of vitamins and minerals to promote wound healing, specifically zinc, and vitamins C and A.
4.Give diet handouts and/or refer to a registered dietitian.
E.Pharmaceutical therapy:
1.Goal of therapy: Prevention of thromboembolism:
a.Trental (pentoxifylline):
i.400 mg tablet:
•Dosage indications based on creatinine clearance (CrCl):
–CrCl less than 10 mL/min: 400 mg, taken once a day.
–CrCl = 10 to 50 mL/min: 400 mg, taken twice daily.
–CrCl greater than 50 mg/min: 400 mg, taken three times a day.
b.Pletal (cilostazol).
i.50 and 100 mg tablets.
•Warning: Metabolites of Pletal are inhibitors of phosphodiesterase III and are contraindicated in patients with congestive heart failure (CHF) of any severity.
•Dosage indications.
–50 mg, taken twice daily if taken in coadministration with ketoconazole, itraconazole, erythromycin, and diltiazem.
–100 mg, taken twice daily at least half an hour before or 2 hours after breakfast and dinner.
ii.81 and 325 mg tablets, taken once daily.
c.Plavix (clopidogrel bisulfate):
i.75 mg, taken once daily.
d.Aspirin (acetylsalicylic acid, ecotrin).