Arterial Insufficient Ulcers Flashcards
Arterial insufficiency
Lack of adequate blood flow -> impaired tissue oxygenation -> wounds
Why are arterial ulcers likely to worsen
Because the amount of O2 required to promote wound healing is significantly greater than that needed to maintain tissue quality
Artery
Larger vessels (aorta, femoral, brachial) maintains blood pressure by expanding during systole and rebounding during diastole
-90-100 mmHg
- Sympathetic stimulation -> vasoconstriction
Arteriole
Have significant sympathetic innervation and play a role in maintaining blood pressure
- 25-35 mmHg
Capillaries
- Single layer of endothelial cells with basement membrane
- 1 mm length, width only for a single RBC to pass through
- Diffusion O2, CO2, and nutrients between endothelial cells to tissues, most tissue 0.1mm away from nearest capillary
- 25-35 mmHg arterial side
- 15 mmHg venous side
Causes of arterial insufficiency
- Atherosclerosis (primary cause)
- Trauma
- Acute embolism
- Diabetes mellitus (d/t causing micro vascular disease, which may impair blood supply)
Arteriosclerosis
Thickening and hardening or arterial walls
- Normally occurs with aging
Atherosclerosis
Systemic, degenerative process with progressive arterial lumen narrowing
- Hypercholesterolemia -> fatty streaks -> plaques ->atheroma -> plaque rupture causing embolism -> can lead to stroke, pulmonary embolism, wounds, aneurysm
- Most commonly deposited at bifurcation of an artery
- Lipids, calcium deposits, scar tissue accumulates on damages intima layer -> progressive vessel stenosis
Intermittent claudication
- Activity-specific discomfort due to local ischemia that stops within 1-5 minutes of ceasing provocative activity
- It is repeatable, predictable at the same workload
- One of the first signs of arterial insufficiency
- Compensatory collateral circulation to bypass occluded vessel but rate of plaque progression may exceed rate of angiogenesis
- Describe feelings of cramping, burning, or fatigue
Obstruction of iliofemoral artery
Complaints of buttock, thigh or calf pain
Obstruction of infrapopliteal artery
Complaints of foot pain
Ischemic rest pain
- Represents more significant arterial insufficiency than intermittent claudication
- Start to see arterial ulcers
- Burning pain exacerbated at night or with elevation, relieved by dependency
- As occlusion progresses, even positioning leg in dependent position may not alter blood flow or patient’s pain complaint
Normal ABI values
1.0-1.3
Symptoms arise when ABI
= 0.7
Claudication pain when ABI
= 0.5-0.9 vascular specialist referral indicated, likely experiencing intermittent pain
Resting pain when ABI
= 0.4-0.5
Tissue loss when ABI
</= 0.3 difficult for healing d/t lack of blood flow
ABI >1.3 indicative of
Possible arterial calcification
More common for ulcers to start from some form of..
Trauma rather than spontaneous skin breakdown
Gangrene
Dead tissue that is dry, dark, cold and contracted
Pain with arterial ulcers
Severe, increased with elevation & relieved with dependent positions
Location of arterial ulcers
Distal toes, dorsal foot, areas of trauma
Periwound and structural changes in arterial ulcers
- Thin, shiny, anhydrous (no sweat) skin
- Loss of hair growth
- Thick yellow nails
- Pale, dusky, cyanotic skin
Arterial ulcer wound presentation
- Clift edges
- Punched out cookie cutter shape
- May conform to precipitating trauma
- Pale granulation tissue if present
- Black eschar, gangrene common
- Little or no drainage
Pulses and arterial ulcers
Decreased or absent pedal pulses
Temperature and arterial ulcers
Decreased
Smoking and risk for arterial ulcers
- Nicotine causes vasoconstriction
- Decreases availability of O2 by increasing amount of nonfunctioning hemoglobin
- Increases rate of clot formation and blood viscosity, decreasing tissue perfusion
- Nicotine enhances cholesterol deposition
Diabetes and risk for arterial ulcers
- Increased prevalence of medial calcific stenosis leading to calcification of tunica media and basement membrane
- Calcium affects diameter and interferes with exchange of O2 and nutrients
- Risk for micro vascular disease secondary to sustained hyperglycemia -> decreases collagen synthesis, angiogenesis, fibroblast proliferation, reduces tensile strength of wound, impairs ability to fight infection
- Co-existing risk of neuropathy masks pain of ischemia
Hypertension and risk for arterial ulcers
- Intimal layer of arteries easily traumatized by increased force of blood -> endothelial cell injury -> atherosclerosis
- SBP more damaging to blood vessels than DBP
- Vessel respond by 1. Thickening smooth muscle layer in tunica media 2. Increasing production of vasoconstrictive agents seen in response to pressure
Mechanical trauma and risk of arterial ulcer
Ill-fitting shoes, stubbing toe
Chemical trauma and risk for arterial ulcer
Over the counter agents such as corn remover or topical home remedy to manage skin and nail conditions
Thermal injury and risk for arterial ulcer
- Heating pads or soaking feet in hot water
- Poor circulation results in increased tissue temp without ability to dissipate the heat -> tissue damage
Advanced age and risk of arterial ulcers
- Less able to adapt to metabolic demands by vasodilating and vasoconstricting
- Rate of arterial insufficiency increases
- Presence of co-existing co-morbidities
- Increased risk of skin trauma (falls)
- Immune and inflammatory response slowed
- Epidermis and dermis have less strength
PT tests and measures for arterial insufficiency
- Pulses
- Ankle-brachial index
- Capillary refill
- Rubor of dependency
- Venous filling time
Assessing pulses
0 = absent
1+ = weak/thready
2+ normal
3+ = full, firm
- Absent dorsalis pedis and/or posterior tibial pulses are independent predictors of major vascular outcome in type 2 diabetes
- Risk increases proportionally with the number of absent pulses
Capillary refill assessment
- Indicator of surface arterial blood flow
- Observe color of patient’s toe
- Pinch distal tip of toe with enough pressure to blanch skin causing emptying of surface blood vessels
- Make note of time required for toe surface color to return to normal after removal of pressure
- Normal time is <2 seconds
Wound care for patient with arterial insufficiency
- Moisturize dry skin
- Avoid adhesives
- Reduce friction between toes
- Provide padding to protect ischemic tissues
- Choose dressing to moisten wound bed
- Debride necrotic tissue is appropriate
- Choose footwear to accommodate for bandages and decrease stress to wound
- AVOID COMPRESSION
Gait and mobility training for pts with arterial insufficiency
Assistive device to off-load extremity typically walker used
Patient positioning for arterial insufficiency
Dependent leg position, avoid elevation, raise head to bed to encourage dependency & increase distal blood flow
Aerobic exercise for pts with arterial insufficiency
- Light, graded exercise program to stimulate collateral vessels, encourage weight loss, improve glucose, raise HDL
Note: excessive exercise diverts limited blood supply away from wound
Flexibility for pts with arterial insufficiency
Tight gastroc -> increase plantar pressures during gait, may result in stress to cause breakdown -> wound
- Light stretching
PT wound care modalities and pts with low ABI
Will be of little use if ABI <0.3 and possibly ABI <0.5
- If no progress seen in 2-6 weeks, reassess plan
Gangrenous tissue must be removed…
Surgically!
Dry gangrene
- Due to loss of nourishment to a part, followed by mummification
- Dry, black, shriveled
- Well-defined line of demarcation with specific localization and auto-amputation
- DO NOT DEBRIDE, IMMEDIATE REFERRAL TO SURGEON
Wet gangrene
- Necrosis of tissue, followed by destruction caused by excessive moisture
- Bacterial gases accumulate in tissue
- Line of demarcation not well defined
- Limb painful and swollen
- Common when infection exists (also frostbite)
- DO NOT DEBRIDE IMMEDIATE REFERRAL TO SURGEON
Walking shoes or cast shoes
- Type of temporary footwear
- Allow room for bandages and high toe box/sufficient length to prevent extra pressure
Rocker-bottom sole
Type of temporary footwear
- Facilitate normal gait pattern, removes pressure on distal toes during push-off
Enclosed shoe
Type of temporary footwear
- Used to protect against foreign objects and cold temperatures
Permanent footwear
- Once wound is healed, pt will move to this
- Extra-depth toe box, adequate length, sufficient space for heavier socks in cooler weather
- Soft flexible material to prevent undue pressure on foot
- Severe deformities/amputations should be referred to an orthotist for custom shoes
Plethysmography
- Electrical impedance, water, air are different methods
- Cuff connected to a force transducer around extremity or digit to be assessed
- Pulsatile nature of blood flow recorded graphically
- Better assessment of regional blood flow in patients with vessel calcification who cannot otherwise be accurately assessed with an ABI (high)
Duplex scanning
Combines directional Doppler probe with a scanner, measures blood flow, velocity, turbulence in arteries and veins
Transcutaneous oxygen monitoring
- Series of electrodes adjacent to wound
- Measure O2 tension in Periwound area
- Measure of tissue O2 content
- Able to detect macro vascular and micro vascular perfusion and objectively quantify healing potential
- > /= 35 mmHg sufficient to support wound healing in chronic ischemic wounds (matches with pressure at capillaries)
- <30 mmHg unlikely to heal without surgery
Arteriography
- Radiopaque dye injected into an artery to better visualize blood flow within the vessel
- Only done if surgical revascularization is being considered as a treatment option
Revascularization
- Surgical intervention method
- Identify most distal segment with normal blood flow and occluded artery segment
- Choose a new conduit (bypass) to replace the diseased segment
- Greater or lesser saphenous vein most commonly used
- Prosthetic graft material such as Gortex or Dacron used
- Pts may have hip flexion precautions following
Percutaneous balloon angioplasty
- Surgical intervention method
- Balloon-tipped catheter is expanded at the site of stenosis, compressing any plaque formations that are obstructing blood flow against vessel wall
- Works best with larger arteries and when length of stenosis is short and clearly defined
- Stents are an alternative
- Rarely improve circulation to the same extent as revascularization and plaques are likely to recur over time
Amputation
- Surgical intervention method
- For severe ischemia, usually preceded by attempts at revascularization
- Level determined by most distal satisfactory perfused arteries and patient’s future mobility
