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