Peripheral artery disease resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ogheneochuko Ajari, MB.BS, MS [2]

Overview

Peripheral artery disease (PAD) is a circulatory disorder due to narrowing of the arteries of the limbs which lead to a reduction in blood flow to the lower extremities. It is most commonly caused by atherosclerosis and generally used to refer to the atherosclerotic peripheral arterial lesions in the lower extremities. PAD manifests commonly as leg pain at rest or exertion and it can be treated successfully with lifestyle modification and reduction of risk factors such as smoking cessation, control of diabetes and hypertension e.t.c. Complications do arise in PAD such as the development of leg ulcers and gangrenous limbs that would occasionally lead to amputation.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

• Antiphospholipid antibody
• Atherosclerosis
• Heparin induced thrombocytopenia
• Trauma to artery

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
Boxes in salmon color signify that an urgent management is needed.

Diagnosis

General Approach

Abbreviations: ABI: Ankle brachial index; PAD: Peripheral artery disease; TBI: Toe-Brachial Index

Suspected PAD

Symptoms: ❑ Leg pain at rest ❑ Reduced or absent pulses ❑ Leg pain during exertion ❑ Gangrene ❑ Pale extremity ❑ Non healing wound ❑ Calf or foot cramping ❑ Paresthesias

Order Ankle brachial index

≤ 0.90

Normal 0.91-1.30

> 1.30

Order Exercise ABI

Order Toe-Brachial Index OR Pulse volume recording OR Duplex ultrasound

Does the patient have > 20% decrease in Postexercise ABI?

Is TBI < 0.7?

Yes

No

No

Yes

PAD confirmed

No PAD

PAD confirmed

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention. The algorithm below is based on the 2005 and 2011 ACCF/AHA guidelines.

Characterize the symptoms: ❑ Leg pain at rest ❑ Leg pain on exertion ❑ Calf or foot cramping ❑ Thigh or buttock pain ❑ Gangrene ❑ Non healing wound ❑ Absent or reduced pulses ❑ Muscle atrophy ❑ Palor (when leg is elevated) ❑ Erectile dysfuntion ❑ Paresthesiss ❑ Paralysis ❑ Redness ❑ Shiny/scaly skin Obtain a detailed history: ❑ History of Risk for lower extremity PAD ❑ Age < 50 years, with diabetes mellitus and one other atherosclerosis risk factor e.g. ❑ Smoking ❑ Dyslipidemia ❑ Hypertension ❑ Hyperhomocysteinemia ❑ Age 50 - 69 years with a history of; ❑ Smoking ❑ Diabetes mellitus ❑ Age 70 years or older ❑ Leg symptoms with exertion (suggestive of claudication ❑ Ischemic rest pain ❑ Abnormal lower extremity pulse examination ❑ Known atherosclerotic coronary, carotid or renal artery disease ❑ History of other risk factors ❑ Low exercise levels ❑ Elevated C-reactive protein ❑ Vasculitis/inflammatory conditions ❑ Trauma ❑ History to determine cause ❑ Walking impairment (e.g. fatigue, numbness, or pain in the buttock, thigh, calf or foot) ❑ Poor healing or non healing wounds of legs or feet ❑ Pain at rest localized to the lower leg or foot ❑ Pain with upright or recumbent positions ❑ Exertional limitation of lower extremity muscles ❑ Postprandial abdominal pain provoked by food with associated weight loss ❑ Family history ❑ First degree relative with abdominal aortic aneurysm

Examine the patient: Vitals ❑ Pulse ❑ Rate ❑ Heart rate ❑ Rhythm ❑ ❑ ❑ Respiration ❑ ❑ Blood pressure ❑ Skin ❑ Inspection ❑ Distal hair loss (suggestive of CLI) ❑ Trophic skin changes ❑ Hypertrophic nails (Suggestive of CLI) ❑ Shiny/scaly skin (suggestive of CLI) ❑ Palpation ❑ Cool lower extremities Abdominal examination ❑ Palpation ❑ Aortic pulsation ❑ Maximal diameter ❑ Auscultation ❑ Bruits Extremities ❑ Inspection/palpation of the feet ❑ Redness (suggestive of CLI) ❑ Perishingly cold (suggestive of ALI) ❑ Ulcers - (suggestive of CLI) ❑ Palor -suggestive of ALI ❑ Muscle atrophy - (suggestive of CLI)

Consider alternative diagnoses: ❑ Arthritis ❑ Chronic compartment syndrome ❑ Spinal stenosis ❑ Symptomatic Baker's cyst ❑ Venous claudication

Order tests: First initial test ❑ Ankle brachial index Additional tests:

Is the patient symptomatic?

Yes

No

Classify based on classical symptoms

Asymptomatic

Proceed to preventive and risk management

Treatment

Shown below is the algorithm for the therapeutic approach for peripheral artery disease based on the 2005 and 2011 ACCF/AHA guideline recommendations.

ACE Inhibitors eg Ramipril for treatment of claudication.