Lesson 3: Aterial Insufficiency Flashcards
Tunica Externa (Adventitia)
Provides support to vessel walls
Protective outer layer
What makes up tunica externa?
Connective tissue, collagen, and elastin
Tunica Media
Middle layer
Modulates vessel diameter
What makes up tunica media?
Smooth muscle, collagen, and elastin
Intimal Layer
In direct contact with blood
Fragile, easily traumatized
What makes up intimal layer?
Single layer of endothelial cells
Arteries
distribute blood, musculature promotes flow
Arterioles
sympathetic vasoconstriction
Capillaries
single layer of endothelial cells
1 mm long, 8–10μm wide
Most tissues only 0.1 mm from nearest capillary
Basement membrane
Pressure in larger arteries?
90–100 mm Hg in the larger vessels
Pressure in capillaries?
25–35 mm Hg
Pressure as blood returns to right atrium?
0mmHg
How do oxygen and nutrients get to tissues?
Oxygen and nutrients flow via capillaries from the blood into the tissues
What are arterial ulcers caused by?
decrease in arterial blood supply
What are some causes of arterial insufficiency?
Trauma Acute embolism Diabetes mellitus Rheumatoid arthritis Thromboangiitis (Buerger’s disease) Arteriosclerosis
How many Americans affected by arterial insufficiency?
8-12 million
Arteriosclerosis
thickening/hardening of arterial walls
Atherosclerosis
systemic, degenerative process; arterial lumen is gradually and progressively encroached upon by build up of plaque
What layer does Lipids, calcium deposits, and scar tissue accumulate?
intimal layer, causing progressive stenosis
Intermittent Claudication
Activity-specific discomfort due to local ischemia
50% stenosis to have claudication
Pain of intermittent claudication:
Pain stops within 1–5 minutes of ceasing the provocative activity
Pain is described as cramping, burning, or fatigue
Pain location is usually distal to the site of occlusion
Ischemic Rest Pain
Burning pain
~70% stenosis to have ischemic rest pain
Arterial insufficiency (ischemic) ulcers more likely
What is ischemic rest pain exacerbated by?
Exacerbated with elevation and relieved by dependency
Progression of atherosclerotic pain:
arterial insufficieny-intermittent claudication-ischemic rest pain-ulcer
Arterial Ulceration
Result of complete or partial arterial blockage limiting perfusion causing tissue necrosis/ ulceration.
Most common places for arterial wounds:
Wounds between toes, on tips of toes, dorsal aspect of foot, over phalangeal heads, adjacent to lateral malleolous/ tibia or where subject to trauma , such as shin, distal calf
What arterial wounds look like:
Dry wounds with black/gray necrotic tissue & erythematous halo
Thin dry skin, absence of hair, shiny, smooth, cool
Borders of arterial wounds:
Well defined borders “punched out” smooth edges
Symptoms of arterial wounds:
Painful
Dry gangrene
Elevational pallor, dependent rubor
Pain with arterial wounds:
Decreased pain in the dependent position, increased with elevation, exercise (claudication)
Pulses with arterial wound:
Pulses absent or diminished
What does ulceration and gangrene result?
when oxygen requirements of local tissue exceed perfusion
What are arterial insufficiency ulcers most commonly due to
trauma to an ischemic limb
Can be spontaneous
5–10% of all lower extremity ulcers
Associated illnesses with arterial insufficiency ulcers
Coronary disease CHF COPD Hypertension Diabetes mellitus End-stage renal disease Hypercholesterolemia
Risk factors contributing to AI ulcers
hyperlipidemia and elevated LDL Systemic process Smoking Diabetes Hypertension Trauma Advanced Age
Hyperlipidemia and Elevated LDL
Increase cholesterol deposition
Promote plaque growth
Systemic process
Those with CAD at increased risk for PAD
Smoking
Causes vasoconstriction and decreases perfusion
Decreases oxygen availability
Increases clot formation and blood viscosity
Increases cholesterol deposition
Increases mismatch between oxygen delivery and oxygen demand
Diabetes Increases prevalence of
Calcific arterial insufficiency Microvascular disease Impairs all 3 phases of wound healing Decreases ability to fight infection Increases risk of neuropathy
Hypertension
Initiates and perpetuates endothelial cell injury
Systolic HTN more damaging than diastolic
How do arteries respond to hypertension?
Thickening tunic media
Increased production of vasoconstrictive agents
Trauma
Mechanical
Chemical
Thermal
Advanced Age
Less able to adapt vessel diameter based on demand
Increased rate of comorbidities
Slowed immune response
Decreased inflammatory response
5PT Method
Pain Position Presentation Periwound Pulses Temperature
Pain
Intermittent claudication
Resting pain
Position
Primarily lower extremity
Commonly toes, lateral malleolus, anterior leg
Rarely above the knee
Trauma key precipitating factor
Presentation
Round, regular, “punched out” May conform to precipitating trauma Pale granulation tissue if present Possible necrotic tissue/black eschar Minimal or no bleeding/drainage
Periwound and Structural Changes
Thin, shiny, anhydrous skin Loss of hair growth Thickened, yellow nails Pale, dusky, cyanotic skin Possible muscle atrophy Possible dependent rubor
Temperature
Decreased
What to consider with AI ulcer healing?
wound size and depth: superficial and smaller heal faster
local tissue perfusion: ABI > 0.5, toe pressure ≥ 50 mm Hg,
tcpO2 > 30 mm Hg
With appropriate interventions, how quickly can AI ulcer begin to heal?
20–40% decrease in size within 2–4 weeks
of appropriate interventions
PT interventions for AI ulcers:
PT services must be coordinated with the patient, caregivers, and other disciplines for maximizing outcomes
Address etiology, risk factors as able
Teach how to modify risk factors
Teach methods to protect at-risk limbs from ulceration
Footcare Guidelines for Patients with AI Ulcers
Protect your feet and legs from: Trauma Chemicals Excessive heat and cold Protect any open wounds Live Healthy Call your clinician if needed
Request for Further Medical Testing
Patients with invalid ABIs
Wounds that fail to progress
Wound culture and sensitivity if suspect infection
Bone scan/X-rays if exposed capsule or bone
Keys to Local Wound Care
Protect surrounding skin
address wound bed
maximize circulation
Protect Surrounding Skin
Moisture dry skin
Avoid adhesives
Reduce friction between toes
Provide padding to protect ischemic tissues and normal temperature
Address Wound Bed
Choose dressings to moisten wound bed
Debride necrotic tissue if appropriate? (must have adequate ABI/perfusion to safely debride)
Maximize Circulation
Avoid compression
Choose footwear to accommodate for bandages and decrease stress to wound
Intervention goals:
protect
promote circulation
educate patient/caregivers
Protect
Use foam dressings to pad area
non-adherent dressing to reduce trauma with dressing changes
no sharp debridement
often will need revascularization to achieve healing
Promote circulation
Warmth
No compression
Modalities
Educate Patient/Caregivers
Wound etiology
Intervention strategies
Risk factor modification
Foot care guidelines
Therapeutic Exercise for AI ulcers
Gait and mobility training Patient positioning Aerobic exercise Resistive exercise Flexibility exercise
Adjunctive Modalities for AI ulcers:
Therapeutic warmth (avoid heating pads, impaired ability to dissipate heat with impaired circulation)
Electrical stimulation
Hyperbaric oxygen
Negative pressure wound therapy
Medical Interventions for AI ulcers:
Manage risk factors Cholesterol, LDL/HDL, triglycerides Blood pressure Blood sugar Pharmacological interventions Pain Circulation (transdermal patches, pentoxifylline, cilastazol) Sympathetic block
Surgical Interventions for AI ulcers:
Debridement
Revascularization
Angioplasty
Amputation
Tests and Measures for AI
Pulses Capillary Refill Rubor of Dependency Venous Filling Time Ankle-Brachial Index Doppler Ultrasound TBI- Toe pressures TCPO2- Transcutaneous oxygen Plethysmography Duplex scanning Arteriography
Most common site for occlusion:
bifurcation of the common femoral artery
Capillary Refill
Reliable indicator of surface arterial blood flow
Push against nail bed with enough pressure to blanch skin and hold for 5 sec
Normal <3 sec for color to return
Delayed capillary refill is an indication of:
Digital ulcer
Abnormal Doppler ultrasound or ABI
Lab-Rubor of Dependency
Indirectly assesses LE arterial flow
Patient supine, note plantar foot color
Elevate the LE 60° for one minute
Normal arterial flow with rubor of dependency:
little or no color change
returns to normal in
15–20 sec (should be very little or no change in color if intact arterial system)
Mild arterial insufficiency:
pallor after 45-60 seconds of elevation
Moderate arterial insufficiency:
pallor after 30-45 seconds of elevation
Severe arterial insufficiency:
pallor within 25 seconds of elevation, dependent rubor
Venous Filling time less than 5 seconds
venous insufficiency
Venous Filling time 5-15 seconds
normal
Venous filling time greater than 20 seconds
arterial insufficiency
Venous filling time indications:
Unable to tolerate ABI
ABI >1.1
History of diabetes or vessel calcification
Suspected concomitant venous insufficiency
ABI results >1 (.1.3)
Calcified vessels if diabetic- requires further evaluation. Do not exceed 250 mmHg, is non-compressible and may damage artery
ABI 1-.95:
No significant Arterial Disease
ABI .95-.8:
Mild disease- Compression with caution
ABI: .8-.5:
claudication- compression contraindicated (usually symptomatic with claudication @.7)
ABI less than .6
debridement contraindicated by ANY means. Inadequate circulation, exposing debrided tissue to infection( Can be double-checked with TCPO2 to determine collateral circulation. )
ABI less than .5
compression contraindicated –resting pain .5-.4
ABI less than or equal to .3:
tissue loss
Calculation of ABI:
systolic pressure of LE/Systolic pressure of UE
Segmental Pressure Measurements
Localizes area of decreased arterial
blood flow
Ideal for identifying distal arterial occlusion or stenosis
What indicates arterial occlusion?
A pressure drop of >20 mm Hg in adjacent segments
Indication of segmental pressure:
Suspected AI in ulcer proximal to ankle
Decreased or absent proximal pulse
TBI- Toe Brachial index
Represents drop in BP in smaller digital vessels
If ABI normal, may indicate small vessel disease
Alternate test for patients that have calcified arteries
Normal TBI:
.75 (.7-.9)
TBI do not debride:
less than .5 or .6
Transcutaneous Oxygen Measurement
Measurement of O2 diffusing across the skin from the capillary beds. May indicate better perfusion than ABI due to collateral circulation.
Transcutaneous Oxygen Measurement not reliable in:
patients with swelling/infection
Transcutaneous Oxygen Measurement less than 20mmHg:
will not heal
Transcutaneous Oxygen Measurement greater than 30mmHg:
will heal
debridement safe
