Ch. 18 Notes
Arterial Disorders
Collateral Circulation- rerouting of blood vessels, in which new blood vessels join to take
over some of the circulation of blocked vessels
Peripheral Artery Disease (PAD)- any disease process that affects the arteries (result in
ischemia)
Atherosclerosis- manifestation of PAD systemic diseases that affect arteries, causes
arterial stenosis, obstruction of thrombosis, aneurysm, ulceration, vessel rupture
- Pt w/ PAD have increased risk of mortality, MI, & cerebrovascular disease
Patho
- Lumen narrows, blood flow decreases, ischemia occurs progressing to infarction in distal
tissue
- Arteriosclerosis: diffuse process where muscle fibers & endothelial linings of the walls of
small arteries & arterioles become thickened
- Atherosclerosis involves changes of intima consisting of accumulation of lipids, calcium,
blood components, complex carbs, fibrous tissue (atheromas/plaques)
Risk Factors
- FMHx, Age, obesity, smoking, pre-existing health conditions (HTN, CAD, DM, etc)
- Nicotine decreases blood flow, increases HR & BP, increases clot formation risk by
increasing platelet aggregation
- Hyperhomocysteinemia is independent for atherosclerosis
- Homocysteine protein that promotes coagulation, elevated levels are associated
w/ genetic factors & diet low in folic acid, B12, B6, & folate
- HTN accelerates rate atherosclerotic lesions form in high pressure vessels
Clinical Manifestations & Assessment
- Critical limb ischemia (CLI), chronic ischemic pain at rest, nonhealing, ulcers, gangrene
- Acute Limb Ischemia (ALI), sudden decrease in limb perfusion, caused by
thrombosis/embolism
- Pt complain of pain in fingers/feet
Focused Assessment of Lower Extremity PAD
- gangrene , ulcers, edema
- Structural changes
- Hair loss ,Thick opaque nails, shiny dry skin, Skeletal muscle atrophy
- Pulse changes
- Diminished, absent below area of stenosis, Cool extremity distal to occlusion
- Skin changes
- Elevational pallor, dependent rubor
- Sensational Changes
- Paresthesias, numbness, tingling in extremities
Focused Assessment Acute Arterial Occlusion
- Pain, pallor, pulselessness, poikilothermia (cool temp to palpation), paresthesia
(numbness, tingling), paralysis
Intermittent Claudication- caused by inability of arterial system to provide blood
- Cramp like pain in muscle
, - Consistently reproduced w/ same degree of exercise/activity
- Relieved by stopping muscle use
- Site of arterial disease can be determined by this
- Pain occurs in muscle groups distal to diseased vessel
- 70-80% pt don’t have worsening s/s
- 10% will progress to critical limb ischemia
- Dependent position reduces pain
Pain
- Arm fatigue may be caused by atherosclerosis & inability to hold or grasp objects
Skin Changes
- Inadequate blood flow causes cool & pale extremities
- When extremity is placed in dependent position after elevation it becomes rubor
- Color changes suggests severe peripheral arterial damage
Pulses
- Unequal pulses between extremities/ absence of normally palpable pulse is sign of PAD
- Bruits: indicate turbulent blood flow that occurs w/ vessel stenosis
Sensory Changes
- Numbness, paresthesias, motor deficits indicate tissue anoxia
Diagnostic Tests
- Continuous Wave (CW) used when pulses are not palpable, doppler US device help
hear pulse
- More useful when combined w/ ankle brachial index (ABI)
Medical Management
- Reduce pt risk for life threatening complications, improve walking distance, salvage
limbs, exercise, pharmacological tx, control HTN, DM, stop smoking, etc.
Management of Intermittent Claudication
- Relieve symptoms, improve exercise performance, improve functional abilities
- Initial tx focused on structured exercise program & pharmacotherapy
- “Walk into pain”
Pharmacologic Therapy
- Cilostazol: phosphodiesterase III inhibitor that is a vasodilator & interferes w/ platelet
aggregation & prescribed in combo w/ exercise program, 3-6 mo use of med
- Antiplatelet agents: help prevent thromboemboli
- Clopidogrel: prevention of cardiovascular ischemic events in pt w/ PAD not claudication
Thrombolysis
- Tx of thrombotic stenosis/ occlusion
- Catheter insertion into affected vessel, thrombolytic agent injected directly into thrombus
& lyse clot
- Pt monitored for signs of bleeding
Surgical Management
- Prevent worsening of ischemia & thrombus propagation manage pain & preserve tissue
- Revascularization & arterial bypass 1st line of intervention