Circulatory disorders Flashcards
What is Chronic Venous Disease
- It is a term used to describe chronic conditions which are caused by veins becoming incompetent
- Chronic Venous Disease in the lower limb can be manifested as varocose veins, Venous Exczema and Venous Ulceration
Detail the main characteristics of the Venous system
- Veins return deoxygenated blood from your organs back to your heart
- The blood in the lower leg must travel against gravity in order to return back to the heart
- Veins in the lower leg are divided into two categories
- Deep Veins - are located underneath the deep fascia layer next to the arteries
- Superficial Veins - are found in the subcutaneous tissue
- Perfotrator veins are used perforate the deep fascia and transfer blood from the superficial to the deep venous system
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Detail the main charecteristics of the Venous system part 2
- Venous system is designed to be a low pressure system in contrast to the arterial (high pressure)
- Both superficial and deep veins are separated by a number of non return bicuspid valves approx every 10cm
- Competent valves allow blood to drain from superficial veins to perforaters into the deep veins and back flow is prevented
- Valves work in unison with lower limb muscle pumps in order to move the blood in an upward direction
Describe the Pathophysiology of Chronic Venous Disease
How does CVD develop
- CVD develops when Venous pressure is increased (venous hypertension) and the return of blood to the heart is impaired
- Incompetence of Bicuspid valves is the main contributer to poor venous drainage resulting in reflux/ retrograde flow (blood flow backwards)
- Valves can be ineffective due to phlebetis (vein inflamattion) direct injury, pre exsiting weakness, DVT damage
- Dusfunction of the calf pump can also cause venus hypertensionas blood will not effectively be drained form the lower limb
Describe how you would manage a patient with Chronic Venous Disease
- The two principal management options for CVD are surgical intervention to correct underlying pathophsyiology or compression therapy.
- Surgical intervention: All patients with symptomatic varacose veins, lower limb skin changes superficial vein thrombosis or healed venous ulcers should be referred to a vascular consultant to asses whether Venous surgery is an option
- Compression therapy: Works in a number of different ways
- Provides structural support to the venous leg pump
- Prevents Venous dialation during walkin
- Increases the velocity of venous blood flow reducing inflamattion
- increases tissue pressure encouraging reabsorption of excess fluid into Venous and lympthaitic systems
- Improves Valvular efficiency
Describe what PAD is
- Peripheral Arterial Disease can be described as the partial or complete obstruction of one or more of the arteries which perfuse (supply blood) the lower limbs causing a reduction in arterial blood supply.
- PAD is a systematic disease (affects the entire body) so patients with PAD have similar risk of death from myocardial infarction, stroke and other vascular causes
What is Atherosclerosis
Atherosclerosis is the thickening in the wall of the arteries caused by fibro fatty plaques. This leads to Stenosis (narrowing of artery) or obstruction (occlusion) resulting in reduced blood flow
What is Claudication
- Claudication refers to the occurrence of muscle cramping or tightness when an exercising muscle requires more oxygen/nutrients than the circulatory system is capable of providing
- The cramp pain is usually experienced Distal to the disease in the arterial tree
- Calf cramp usually means claudication in the Superficial femeral artery deep artery within the thigh
- thigh cramp usually means the disease is present in the profunda artery (branch of superficial femoral artery)
- Buttock claudication usually means disease is in the aorta/iliac system (arteries within abdomen and pelvis)
What are the symptoms of PAD Peripheral Arterial Disease
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- The primary symptom of PAD is Intermittent Claudication.
- IC can be described as severe cramp or tightness in the calf, thigh or buttock area present after a short period of excursion, after which symptoms settle with rest but return with muscle exercise.
- It never occurs when a patient is at rest sitting or lying down.
What are the risk factors for Peripheral Arterial Disease
- Smoking
- Hypertension (High blood Pressure) 140/90mmHG or higher
- High Cholesterol
- Diabetes
- History of Cardiovascular Disease
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What is Ischemia
Refers to the restriction of blood flow (oxygen) to a certain part of the body
What is ischemic Rest Pain
- It occurs with servere or critical limb ischemia
- Blood supply to distal tissues and nerves has deteriorated so much that the supply of oxygenated blood does not meet local metabolic demand even at rest
- It is described as extremely painful with a constant burning sensation felt in the toes, thought to be worse in bed due to the feet being elevated (reducing the hydrostatic pressure to the distal small arteries in the feet)
What is used to clinically diagnose PAD Peripheral Arterial Disease
- Palpation of peripheral pulses can help to identify and locate the site of stenosis occlusion and the level of abnormality
- ABPI is a more valid reliable marker for PAD offering an objective measure of the severity of symptomatic PAD
What is the ABPI Ankle Bronchial Pressure index test
It is basically a comparison between the blood pressure measured in the arm (Brachial) and the pressure measured in the ankle (Dorsalis Pedis or Posterior tibial arteries) which indicates the severity of the Peripheral Arterial Disease present.
The lower the ankle pressure is compared to the brachial pressure, the more significant the disease is
Detail how the ABPI test is performed
- ABPI uses both Brachial readings and ankle readings
- Ensure patient is lying in a supine position and is relaxed
- Locate the brachial pulse, and apply the blood pressure cuff to the patients arm ensuring you can still access the brachial artery
- Apply gel and use the Doppler to locate an audible signal in the artery.
- The blood pressure cuff is then inflated until the artery is occluded and the sound is no longer audible through the doppler
- The cuff is then slowly released and the pressure at which the sound is audible again is recorded
- This process should be repeated in both arms and legs
- The ABPI Ratio is calculated by dividing the highest ankle pressure by the highest systolic pressure in the arm