Diseases of Blood vessels

Atherosclerosis / arteriosclerosis

• Arteriosclerosis - term describing arterial disorders in which degenerative changes result in decreased blood flow

• Atherosclerosis - most common form of arteriosclerosis where thickening and hardening of vessel walls due to lipid accumulation

• Found mainly in large- and medium-sized arteries, such s aorta and its reaches, coronary arteries and arteries hat supply the brain

• Arteriosclerosis - mainly affects arterioles

Aetiology of Atherosclerosis / arteriosclerosis

No known cause, risk factors:

• Hypertension

• Cigarette smoking (nicotine has a vasoconstricting effect)

• Hugh lipid levels in blood

• Familial history

• Obesity

• Diabetes mellitus (Hugh serum glucose levels cause vascular damage)

• Lifestyle

• Alcohol

• Gender (men are at higher risk)

Investigations of Atherosclerosis / arteriosclerosis

• Full blood chemistry

• Doppler ultrasound

• Electrocardiogram

• Arteriogram

Pathophysiology of Atherosclerosis

• Atherosclerosis is a form of arteriosclerosis where wall of arteries are har, thick and narrow due to lipid accumulation within arterial walls

• Lipids are deposits on tunica intima of damaged blood vessel where oxidation of low-density lipoproteins takes place

• Oxidised LDL then enters tunica inima of arterial walls Lipids where they are ingested by macrophages

• Lipid-filled macrophages then become foam cells

• Once foam cell accumulate in significant numbers, they form a lesion called a fatty streak, which over time causes a bulge in Lyme of blood vessel and restricts blood flow

• Affected blood vessels become hard, lose their elasticity, restrict blood flow and eventually occlude the artery

• Greater BP is needed to push the blood through these narrow blood vessels, leads to hypertension

• Although atherosclerosis can affect any organ or tissue, arteries supply heart, brain, small intestine, kidneys and lower extremities

Signs and symptoms of atherosclerosis

• Diminished or absent pulses

• Skin is pallor or cyanoses

• Pain

• Muscle weakness

Care and management of atherosclerosis

• Health promotion to prevent disease must include advice on healthy diet and regulation the lipid levels within normal range. Regular physical examination by person’s GP in order to monitor BP and cholesterol levels should be encouraged

• Advice on cessation of smocking and alcohol consumption should be offered as these are identified risk factor

• Patients should be advised to lose weight if obesity is a problem

• Encourage patient to undertake programmed exercise under the supervision of healthcare professionals. This will help lowering their weight and cholesterol level, and reducing their BP and stress

Pharmacological interventions for atherosclerosis

Aim is to restore blood flow and prevent disease

• Antihypertensives such as beta-blockers

• Anticoagulant therapy with heparin

• Lipid-lowering drugs such as simvastatin

• Antiplatelet drugs

Some patients, surgical procedures, such as balloon angioplasty, may be indicated to improve blood flow through the vessels

Hypertension

• Refers to sustained elevation in systemic arterial BP

• Elevation may be in either systolic or diastolic pressure, or in both

• A normal upper limit for an adult is 130-139 / 85-89mmHg and any reading consistently above this are considered as hypertensions

• Classifications of hypertension include: primary or essential hypertension, secondary hypertension where there is an underlying cause, such as renal diseases or tumour of the adrenal medulla, malignant hypertension occurs in younger age groups with renal and collagen diseases, isolated systolic hypertension mainly occurs when a combination of factors is seen in the elderly and is due to increases in cardiac output, increased peripheral resistance and renal vascular resistance

Aetiology of hypertension

Primary cause or causes of primary hypertension is unknown, several risk factors include:

• Obesity

• Stress

• Cigarette smoking and alcohol consumption

• Excessive intake of sodium causing fluid retention

• Family history

Secondary hypertension:

• Renal diseases

• Crushing’s disease

• Hypo/hyperthyroidism

• Oral contraceptives

• Excessive alcohol consumption

• Coarctation (narrowing) of aorta

Investigations of hypertension

• Full blood chemistry

• Physical examination

• Electrocardiogram

• Assessment of risk factors

Common presenting symptoms of hypertension

• Many patients are unaware that they have hypertension and go untreated

• They ignore symptoms such as headache, dizziness, nosebleed and fatigue

• It is frequently identified through BP screening or as a result of other disease

• Some patient have reported blurred vision and tinnitus, but usually when symptoms do occur, the diseases is at an advanced stage

Non-pharmacological interventions for hypertension

• A single recording of raised BP does not indicate patient is suffering from hypertension. At least 3 recordings at different intervals are required for confirmation. Some doctors use 24hr ambulatory monitoring device - more accurate than BP done in clinic

• Advise patient to restrict sodium intake - sodium promotes water retentions - resulting in increased circulating blood volume and cardiac output

• HCPC advise patient on cessation of smoking and excessive alcohol

• Obese patients - weight redacting through exercise - lower cholesterol levels and help control underlying problems.

• Dietary advice - rich in fruit and veg and low in saturated fats. Reduction of salt in cooking required.

• Encourage reduction of stress levels as it increases workload on heart.

Pharmacological interventions

• Diuretics are prescribed to reduce fluid load - leads to reduction in cardiac output

• Medications, e.g. beta-blockers, calcium channel blockers and angiotensin-inverting enzyme inhibitors

Aneurysm

• Permanent dilation of artery or chamber of heart

• Can occur in both veins and arteries, aorta and arteries at base of brain are the vessels most susceptible

• Occur in localised part of aorta or along blood vessels due to constant pressure

• Comments cause - atherosclerosis because fatty deposits erode and weaken vessel wall

Aetiology of aneurysm

• Atheroscelrosis - main cause affecting descending aorta

• Infection - mainly syphilis affecting ascending aorta

• Hypertension - due to constant pressure, weakening vessel wall can occur in elderly

• Cystic medial degeneration- mainly affects thoracic aorta in disorder called Mafan’s syndrome - affects elastic fibres in tunica media

Investigation of aneurysm

• Full blood chemistry

• Angiography

• Ultrasound

• Chests-ray

Symptoms of aneurysm

• Pain in abdominal region or extremities sue to compression of neighbouring organs

• Dyspnoea (shortness of breath or difficulty breathing) due to pressure on internal organs

• Dysphagia (difficulty in swallowing)

• Signs and symptoms of cerebrovascular accident occur if cerebral arteries are affected

Care and management of aneurysm

• Surgery - virtual that full assessment of patient is maintained. May include insertion of graph

Pharmacological interventions of aneurysm

• Antiphypertensives

• Anticoagulants

• Antibiotics

• Analgesics

Deep vein thrombosis

• Formation of a thrombus in the veins when flow of blood is reduced

• Primarily occurs in veins of lower extremities, such as femoral, popliteal and deep veins of the pelvis

Aetiology of DVT

• Stasis of blood in veins, which can result from immobility after surgery

• Obstruction to flow of blood in veins as a result of trauma

• Hyper coagulability of blood due to dehydration, hormone replacement therapy and oral contraceptive pill

• Use of intravenous cannulae may cause damage to tunica intima, resulting in formation of clots

Other factors: age (40+), obesity, pregnancy, varicose veins and smoking

Pathophysiology of DVT

• Can develop in superficial or deep veins of legs

• Blood flow in sluggish in affected vessels and clotting cascade takes place

• Platelets aggregate at site of injury to vessel wall or where there is venous statis - occurs because platelets are exposed to collagen (protein in connective tissue, which is found in inner surface of blood vessel)

• When platelets com into contact with exposed collagen, they release adenosine diphosphate and thromboxane - make surface of platelets sticky and as they adhere to each other, a platelet plug is formed

• Other cells such as red blood cells are trapped in fibrin mesh and thrombus grows

• Thrombus triggers inflammatory response, causing tenderness, swelling and erythema at the affected site

• Initially thrombus stays within affected area; however, fragments of thrombus may become loose and travel through circulation as an embolus, which may lodge in lungs and cause pulmonary embolism

Signs and symptoms of DVT

• Usually asymptomatic

• Dull aching pain in affected limb, especially when walking

• Oedema of affected leg

• Cyanosis of affected leg

• Redness and warmth on affected part

• Dilation of surface vein

Care and management of DVT

• Maintain patient on bed rest until mobilisation is encouraged

• Monitor vital sings

• Observe calf muscle for swelling. Measure circumference 10-20cm above and below the knee

• Elevate foot to promote venous return and reduce oedema

• Patient advised not to massage affected calf muscle so as not to dislodge clot

• Assessment of pain - patient lies flat with their legs straight and dorsiflexes the foot quickly - positive if complaints of calf pain

• Check every 4 hours if patient is experience any pain of discomfort

• Patient should maintain fluid intake

• Check to ensure that compression stockings are fitted correctly

Pharmacological interventions of DVT

• Anticoagulants such as low-molecular-weight heparin

• Anti platelet drugs

• Anti-inflammatory drugs

• Thrombolytic drugs