10 and 11 - Peripheral Vascular Disease Flashcards
What is peripheral vascular disease?
- Any compromise of the circulation outside of the heart
Arterial
- Occlusive vs. Functional
- Peripheral Arterial Occlusive Disease (PAOD) = most common vascular disease
Venous
- Varicose veins
- Valve disease
Etiology of arterial vascular disease
- Atherosclerosis (narrowing of the artery) = most common etiology
- Mechanical occlusive disorders
o Thrombi (clot)
o Emboli
o Hematological disorders - Vasculitis and arteritis = acute problem of inflammation
- Buerger’s Disease (thromboangiitis obliterans) = related to smoking, very severe arteritis
- Vasospastic disorders = Raynaud’s is the most common (functional problem)
- Combination of factors listed above
Arterial atherosclerosis
- Intimal and smooth muscle proliferation
- Accumulation of matrix & lipids
- Results in narrowing, hardening or weakening
- Provides nidus for thrombus
- Provides source of emboli
Atherosclerosis risk factors
- Hypertension, hyperlipidemia
- Diabetes
o Most common occlusion is under popliteal at the “trifurcation”
o Diabetics tend to develop more severe peripheral arterial disease at a younger age - Advanced age, male Gender
- Family History
- Stress
Clinical manifestations of PVD
- Diminished or absent pulses due to arterial occlusion
- Pain
o 1st = Leg pain with walking (claudication)
Claudication is a problem with exercise, but they may never have an ulcer form
o 2nd = Ischemic rest pain
A progression from claudication – more severe, critical ischemia*** - Slow healing wounds and tissue damage (ulcer or gangrene)
Clinical indicators of the quality of distal perfusion
- Pulses and capillary refill time
- Skin color and temperature
o Rubor on dependency (purple legs when they are hanging down)
– Due to ischemia and toxic byproducts in the skin
– When you elevate this foot, it will rapidly become very white (pallor)
o Pallor on elevation (Buerger’s sign)
– When the elevated foot is white (pallor)
o Acrocyanosis (bluish or purple coloring of the hands and feet caused by slow circulation) - Skin tone and turgor (hydration)
- Hair growth on toes (hair needs oxygen to grow) and status of nails
- Presence of tissue injury (gangrene, ulcers)
o Gangrene a type of necrosis caused by a critically insufficient blood supply
Ischemic ulcers
- Dry, distal ulcers that cause severe pain (unless neuropathy is present in the limb)
o Ischemia is typically painful (same as a heart attack) - Ulcers have irregular edges, poor granulation (new tissue formation) and exhibit little bleeding with manipulation (by definition, little blood is present)
o Other signs of arterial insufficiency present as well - Generally you do NOT debride the tissue right away – priority infection/circulation assessment
Clinical features of ischemic ulceration
o Distal extremities (as we get more distal, the arterial system is smaller, more vulnerable)
o Full thickness (through all layers of skin)
o Dry necrosis (unless infected) with poor granulation
o Variable locations and spontaneous expansion of affected areas
o Poor pedal pulses and Doppler signal
Associated findings with ischemic ulceration ***
o Pain (claudication, night pain, rest pain)
o Dependent rubor, elevation -pallor
o Skin atrophy and nail dystrophy
o Decreased skin temperature
REVIEW - arterial ulcers
- Distal extremities, full thickness ulceration
- Dry necrosis with poor granulation
- Spontaneous expansion
- Pain, atrophy, pallor and rubor
- Poor pulses and Doppler
Arterial thrombus
- In situ (local) clotting occluding the vessel
- Gradual onset of worsening ischemia
- Signs of arterial disease
- Atheroma already present
Arterial embolus
- When a portion of a proximal plaque breaks off and continues to flow until it reaches an artery that it can’t fit through
- Sudden and severe ischemic symptoms
- No preexisting arterial symptoms
- Identifiable source of free body (atrial fib)
- Signs of PAOD not necessarily present
Embolus pathology
- Proximal atheroma or clot (thrombus) breaks off and floats distally, causing an acute onset
- Ischemic damage is based on the distribution of the occlusion
- Pulses may be normal and 85% of emboli are cardiac in origin (A-fib)
What to focus on so far
NEED TO KNOW THE CLINICAL SIGNS AND SYMPTOMS OF THE OCCLUSIVE PHENOMENONS
Raynau’d phenomenon
- FUNCTIONAL arterial problem
- Epidemiology
o 2% of the population experiences Raynaud’s phenomenon - Pathophysiology
o Episodic reduction in peripheral blood flow in response to cold exposure or stress
o This is NOT an occlusive (atherosclerotic) disorder, but rather a vascular malfunction - Skin color changes
o White – ischemia from vasoconstriction
o Blue – venous stasis
o Red – hyperemia - Sensory changes
o Pain and paresthesias (“pins and needles”) - Treatment
o Nifedipine
o V Prostacyclin or prostaglandin E1 for severe cases
o Evening primrose oil
Venous ulceration anatomy
- Arterial system
o High pressure system of blood “in flow” - Venous system
o Low pressure system of blood “out flow”
o Includes superficial veins, deep veins, perforating veins, all with one way valves - Valves
o Veins have one-way bicuspid valves opening to the deep system
o The valves close when pressure rises in the deep system preventing retrograde flow
o Transmission of elevated pressure to the superficial veins