Peripheral vascular disease is used to refer to peripheral artery disease, meaning narrowing of the arteries due to plaques, occurring outside the heart and brain. What are some risk factors for atherosclerosis?
- Family History
- Obesity/Lack of exercise
- Homocysteinemia (Deficiency in B vitamins -> Disorder of Methionine Metabolism -> Build up of homocysteine and other metabolites -> Increased oxidative stress -> Accelerated Atherosclerosis )
What are the two subsets of peripheral vascular disease?
1. Intermittent Claudication: functional ischaemia (not on rest)
2. Critical Limb Ischaemia: Ischaemic rest pain or tissue damage (ulceration or gangrene)
How is peripheral artery disease diagnosed?
- Vascular History
- Physical Exam
- Ankle Brachial Index Measurement (ABI)- Ratio of systolic blood pressure in ankle to arms, Normal .9-1.2, less suggests peripheral vascular disease
- Non-Invasive Vascular Exams
What is the pathophysiology of intermittent claudication?
- Narrowing of the lumen of the arterial supply of the lower limb leads to decreased blood flow ->
Decreased O2 supply to lower limb ->
Anaerobic Metabolism ->
Increased Lactic Acid ->
Pain with increased muscle use
Over time tissues become ischemic leading to:
- pain at rest
- poor wound healing
As disease progresses patients may not be able to ambulate and gangrene occurs
What are key features of intermittent claudication?
Defn: Intermittent claudication is the stenosis, occlusion or aneurysmal dilation of lower limb arterial branches.
- Exertional aching/cramping pain that is relieved on rest.
- It occurs most commonly in the muscle groups of the buttocks, calves, hips and legs
- reproducible from one day to another on similar terrain
What is an ischemic ulcer?
An ischaemic ulcer is an ulcer found on toes/between toes/ on the dorsum of the foot. It is characterised by local skin necrosis and is often noticed after trauma when there is a persistent wound that will not heal.
What is gangrene?
Defnition: Gangrene is a potentially life threatening condition that arises due to necrosis of a considerable mass of body tissue.
- It is characterised by: a blackened dead area, the affected limb being at extreme risk for necrosis.
Wet vs Dry:
- Occurs at distal part of the limb mainly occurs due to arterial occlusion leading to ischaemia
-there is limited putrefaction and bacteria failure to survive
- Occurs in naturally moist tissue and organs such as mouth, bowel,lungs.
- It is characterised by thriving bacteria and septicemia can often occur
- Bacterial infection that produces gas within tissues
- Usually caused by Clostridium Perfringens
- Can travel quickly to healthy tissue -> Medical Emergency
Outline the features of a vascular exam.
- Skin: Thin, Brittle, Shiny. with opaque toes
- Often cool with no toe hair
- Poor capillary refill
- Inspect the feet for ulcers, fissures calluses, tinea and evaluate overall foot care