CARDIOVASCULAR MODULE:

ARTERIAL OCCLUSIVE DISORDER

Adult Medical-Surgical Nursing

Peripheral Arterial Occlusive Disorder is a disruption of the peripheral arterial circulation obstructing the flow of oxygenated blood to the tissues

It may occur as an acute emergency

It may be gradual, progressive and chronic

Arterial Occlusive Disorder: Description

Acute Peripheral Vascular Occlusion:

Acute Vascular Occlusion: Aetiology

The artery is blocked by:An embolism (the most frequent cause) from: An aneurysmInfective endocarditisMyocardial infarctionMitral valve disease/ atrial fibrillationProsthetic heart valvesLocalised trauma

Acute Vascular Occlusion: Pathophysiology

An embolism from the left side of the heart or from an aneurysm passes to the peripheries: (the limbs or mesenteric arteries)

The embolism lodges at a site of arterial branching or atherosclerotic narrowing*

This impairs or cuts off the blood supply distal to the occlusion → ischaemia

May lead to infarction of the tissue

(*Also a thrombus may form at an atherosclerotic site with the same result)

Clinical Manifestations

Sudden onset of: (6 “p” s)PainPallorPulselessnessParaesthesiaParalysisPoikilothermia (cool to touch)→ tissue discoloration of affected limb →

gangrene

Acute Vascular Occlusion: Diagnosis

Acute emergency

Diagnosis from history and clinical picture

Doppler Ultrasound

Emergency Treatment

Early treatment to remove embolus/clot and re-establish circulation

Anticoagulation to prevent further extension of clot or more emboli

Embolectomy by balloon catheters distal and proximal to clot or

Surgery: “Thrombo-endarterectomy”: removal of embolus, and stent or graft to keep artery patent

Thrombolytic drug may be possible if very recentAnticoagulants or anti-platelet aggregation drugs

long-term

Follow-up and Long-term Care

Follow-up angiogram to ensure full patency

Long-term anticoagulant or antiplatelet therapy (to prevent recurrence)

INR during anticoagulation

Treat the cause if appropriate

Nursing Responsibilities

ICU post-op: Bedrest with initial immobility of the affected

limbMonitor anticoagulant therapyMonitor vital signs and fluid balanceMonitor:Colour, temperature, sensation, mobility and

pulses of affected limb post-operatively*Observe arterial wound dressing very

carefully (risk of major haemorrhage)

Chronic Peripheral Arterial Occlusive Disease (PAD):

Chronic PAD: Description

A progressive insidious narrowing and eventual occlusion of the peripheral arteries to the extremities, usually the legs

Occurs in men more than womenAge group 60 - 80 years

Arteries affected are aorto-iliac, femoral, popliteal, tibial, peroneal

Chronic PAD: Pre-disposing Factors

Smoking (most important)*HyperlipidaemiaHypertensionDiabetes Mellitus (macrovascular disease –

accelerated atherosclerosis)Obesity and sedentary lifestyleFamily tendency

Chronic PAD: Pathophysiology

Atherosclerosis:Leads to gradual thickening of the intima and

media of the arteries and narrowing and occlusion of the vessel lumen

Tends to be segmented with good patches between atherosclerotic narrowing

Gradual development of collateral circulation because of increasing ischaemia to distal tissues

Ischaemia can lead to ulceration and gangrene (although collateral circulation may prevent this)

Chronic PAD: Clinical Manifestations

Note:When symptoms occur there is already 75%

narrowing of the arteries

Chronic PAD: Clinical Manifestations

Calf pain on exercise “intermittent claudication” (lactic acid formation) → later:

Pain at rest (mainly feet and toes from nerve ischaemia)

Pain is felt more at nightPain relieved by legs dangling below the

patient to increase the blood supply by gravity

Clinical Manifestations (continued)

Paraesthesia:Numbness and tingling, burning Shooting pains to toes and feetPallor: blanching on elevationHyperaemia: red or bluish dusky skin when

limbs dependent Shiny skin with loss of hairPulses weak or absentSkin and tissue atrophy: poor healingIschaemic ulcers on bony toes → gangrene

Chronic PAD: Diagnosis

Doppler ultrasound: velocity of blood flow

Duplex imaging: Doppler mapping

Segmental BP: (at thigh, calf, ankle): should be the same as brachial. As disease progresses leg BP ↓

Angiography: aorta and femoral arteries assessed prior to intervention or surgery

MRI

Chronic PAD: Management

This a chronic progressive disease formerly with no treatment apart from palliative care

VasodilatorsAnalgesia Exercise encouraged as condition allowsSurgery* may be considered for severe and

disabling claudication to avoid risk of amputation: Endarterectomy, By-pass Graft or Stent

(the patient’s overall health is an important consideration)* Anti-platelet cover if graft/ stent

Chronic PAD: Nursing Considerations

Gentle exercise encourages development of collateral circulation

Encourage to avoid smokingAvoid obesityKeep feet and legs warm and cleanObserve for potential ulcers If surgical intervention: post-operative initial

immobility of affected limbSpecial monitoring of pulses, colour, sensation

and temperature of both limbs (to compare)