chap. 22 - peripheral vascular system

arteries

carry oxygenated, nutrient-rich blood from the heart to the capillaries

• arterial walls → thick + strong to withstand high pressure, contain elastic fibers to stretch with each heartbeat

  • each heartbeat — creates a surge of blood = arterial pulse

pulse amplitude (0-4+ scale)

0 = absent

1+ = weak, diminished (easy to obliterate)

2+ = normal (obliterates with moderate pressure)

3+ = strong (requires firm pressure to obliterate)

4+ = bounding (cannot obliterate)

allen test

evaluates patency of radial + ulnar arteries

• normal/patent artery → palm color returns in 3-5 secs

• abnormal/occluded artery → persistent pallor = arterial insufficiency

steps:

1. patients rest hand with palm up + make a fist

2. occlude both radial + ulnar arteries with thumbs

3. patient opens hand → palm appears pale

4. release pressure on 1 artery

veins

carry deoxygenated, waste-laden blood from tissue back to the heart

• upper body → superior vena cava → right atrium

• lower body → inferior vena cava → right atrium

• hold 70% body blood volume (low-pressure system)

• vein walls → thinner + less muscular than arteries, larger in diameter + can expand to accommodate increased volume (reduces workload on heart)

how veins work

veins operate in a low-pressure system (no strong pump pushes blood forward)

• blood from legs must travel upward to the heart against gravity

venous return: 1. one-way valves

• found in deep, superficial, and perforator veins

• prevent backflow + keep blood moving toward the heart

venous return: 2. skeletal muscle contraction

• walking + movement “milk” blood up the legs

• muscle squeezes veins → pushes blood through valves

venous return: 3. pressure gradient from breathing

• inspiration → decreases intra-thoracic pressure + increases abdominal pressure

• creates a gradient that helps pull blood upward

valve opening

valves open when leg muscles squeeze on the vein and this lets blood movie in an upward direction

valve closing

valves close when the leg muscles relax and this prevents blood from leaking downward

capillaries

connect arterioles to venules + regulate fluid balance

• maintain equilibrium between vascular + interstitial spaces

capillaries key processes

1. hydrostatic pressure pushes oxy, water, nutrients out of capillaries into tissues

2. tissues pick up nutrients + release waste products (CO2, metabolites)

3. osmotic pressure pulls fluid back into capillaries

4. remaining excess fluid is collected by lymphatic capillaries

MATTERS bc it is essential for perfusion, fluid balance, and preventing edema

lymphatic system

works alongside vascular system to drain excess fluid + maintain balance

• removes extra fluid and proteins from interstitial spaces and returns to venous circulation

interstitial space

fluid filled spaces located between cells + tissue

• acts as a reservoir for fluid → can lead to edema if not drained properly

peripheral artery disease (PAD)

narrowing/blockage of arteries from plaque buildup (atherosclerosis)

• leads to reduced or stopped blood flow → tissue damage

• complications → heart attack, stroke/TIA, renal artery stenosis, amputation

PAD s/s

• intermittent claudication (leg pain with activity relieved by rest)

• atypical leg pain (non-classic presentations)

• ischemic rest pain (constant forefoot pain; worse with elevation, improved with dependency)

• leg numbness or weakness

• coldness in the lower leg or foot, sores on toes, feet, legs that wont heal

• change in color of legs

• hair loss or slower hair growth

PAD prevention/education

• quit smoking

• control diabetes + keep A1C in target range

• exercise regularly

• maintain healthy BP, cholesterol, weight

• eat a heart-healthy diet low in saturated fat

venous insufficiency

occurs when leg veins struggle to send blood back to the heart, causing blood to pool (stasis)

• damage to vein walls impairs blood flow

• primarily caused by damaged vein valves or prior blood clots (DVT)

• managed w/ compression stockings, elevation, exercise

venous insufficiency risk factors

• long periods or standing, sitting, immobility

• lack of muscle activity → blood pools in legs

• varicose veins (dilated, tortuous) increase venous pressure

venous insufficiency s/s

• pain → aching, cramping

• pulses → present but may be difficult to palpate through edema

• skin → PIGMENTATION in gaiter area

  • thickened + tough

  • REDDISH-BLUE color

  • associated w/ dermatitis

venous insufficiency grading scale

• stage 0-1 → no visible signs or spider veins/mild reticular veins

• stage 2 → visible varicose veins

• stage 3 → edema (swelling) without skin changes

• stage 4 → skin changes (discoloration, eczema, lipodermatosclerosis)

• stage 5-6 → healed ulcer (5) or active, open skin ulcers (6)

venous insufficiency ulcer characteristics

• location = medial MALLEOLUS or anterior TIBIAL area

• pain = superficial: minimal pain, but may be very painful

• depth = SUPERFICIAL

• shape = IRREGULAR border

• base = granulation tissue → beefy RED to YELLOW fibrinous in chronic ulcer

• leg edema = moderate to severe

SWOLLEN, DISCOLORATION in leg

ELEVATION HELPS

arterial insufficiency ulcer characteristics

• location = tips of TOES, toes webs, heel, other pressure areas

• pain = VERY painful

• depth = DEEP (often involves joint space)

• shape = CIRCULAR

• base = PALE BLACK to dry + gangrene

• leg edema = minimal unless extremity kept in dependent position constantly to relieve pain

HAIR LOSS + SHINY/THIN SKIN in legs

ELEVATION DOES NOT HELP

raynaud disorder

vasoconstriction/vasospasm of fingers or toes

• rapid color changes = pallor → cyanosis → redness

  • darker skin = dusky, dark blue/purple tones

• episodes usually bilateral + last mins to hrs

• common in → female at birth + under age 30

raynaud disorder s/s

swelling, pain, numbness, tingling, burning, throbbing, coldness

thrombophlebitis (superficial)

results from thrombus formation in superficial veins

• often seen w/ unilateral localized pain, achiness, edema, redness, warm to touch

• due to intravenous (IV) lines or injury to vein

lymphedema

results from damaged or blocked lymphatic circulation

• caused by → cancer treatments (breast surgery)

• usually affects 1 extremity

• prominent venous patterning w/ edema may indicate venous obstruction

lymphedema stage 1

asymptomatic

• no visible swelling

• early functional changes only

lymphedema stage 2

reversible/early swelling

• noticeable swelling (may decrease w/ elevation)

• skin soft + pits slightly

lymphedema stage 3

irreversible/moderate lymphedema

• persistent swelling w/ no elevation improvement

• skin changes begin (fibrosis, thickening, firmness)

• limb becomes harder/heavier

lymphedema stage 4

lyphostatic: elephantiasis

• extensive swelling + severe enlargement of limb

• marked skin thickening + scarring

• tissue fibrosis + deformity present

pitting edema

temporary swelling caused by water retention

• often heart or venous issues (associated w/ systemic problems: heart failure, hepatic cirrhosis)

• leaves dimple when pressed

• usually responds to elevation + meds (diuretics)

older adult considerations

• w/ arterial disease → coldness, color change, numbness, abnormal sensations

• w/ aging → lymphatic tissue is lost, resulting in smaller + fewer lymph nodes

• hair loss on lower extremities (not absolute sign of arterial insufficiency)

• varicosities = common