Peripheral Vascular Disease Flashcards
What is peripheral vascular disease?
PVD is a chronic condition that is a result of atherosclerotic disease in the arteries of the limbs
How does extent of atherosclerosis affect symptoms in PVD?
the level of arterial occlusion present is proportional to the severity of the symptoms
What are the risk factors for peripheral vascular disease?
the risk factors are the same as for coronary artery disease (CAD)
- hypertension
- dyslipidaemia
- high LDL and low HDL
- diabetes
- obesity
- advancing age
- male gender
- family history of arterial disease
- significant if a first degree relative had MI before age 55
- smoking
How does peripheral vascular disease typically present?
pain in the lower limbs that is brought by exertion and relieved with rest
typically the patient will be able to walk a specific distance before the pain comes on
it can present as an emergency as acute limb ischaemia
What % of the population are affected by PVD?
it affects 10-15% of the population
What condition is nearly always present in patients with PVD?
75% of patients with PVD also have symptomatic coronary artery disease (CAD)
in the other 25% of patients it is thought that the PVD masks their CAD as they do not exert themselves sufficiently to bring on the CAD symptoms
What is the name of the type of pain present in PVD?
intermittent claudication
this decribes pain/cramping in the lower leg due to inadequate blood flow to the muscles
this often makes the patient limp
What is the classical presentation of PVD?
pain = intermittent claudication
- pain in the calves on walking that is relieved with rest
- pain can occur anywhere along the leg and down into the foot
- pain may occur when legs are raised (in bed) and is alleviated when legs are lowered (sitting)
Why do some patients with PVD not present with the classical picture of intermittent claudication?
often because they are not doing enough physical activity to induce the symptoms
particularly if they have another comorbidity that limits their activity
What is the main differential for peripheral vascular disease?
spinal claudication
caused by impingement of the cauda equina by a spinal stenosis
this classically causes pain in the back of the legs on exertion
What clinical test is performed that is specific to PVD?
Buerger’s test
this is an assessment of arterial sufficiency
the vascular angle (Buerger’s angle) is the angle the leg has to be raised before it becomes cold/pale, whilst lying down
How is Buerger’s angle different in a healthy person and someone with PVD?
healthy person:
- the toes and sole of the foot remain pink even when the limb is raised to 90 degrees
PVD:
- elevation to 15-30 degrees for 30-60 seconds may cause pallor
- Buerger’s angle of <20 degrees** indicates **severe PVD/ischaemia
How is capillary refill time changed in a patient with PVD?
- press the distal phalanx of patient’s toe with a finger for 5 seconds
- blanching discolouration should return to normal in less than 2 seconds
- capillary refill time is PROLONGED (>2 seconds) in someone with PVD due to poor peripheral perfusion
What skin changes may be present on the lower limb of someone with PVD?
there may be evidence of poor skin health due to poor perfusion, such as:
- ulcers
- dry, scaly skin
- cool peripheries
- prolonged capillary refill time
oedema should not be present
What pulses are assessed in PVD?
What does the presence or absence of a pulse suggest?
the pulses in the foot - posterior tibial & dorsalis pedis
- palpable pulse indicates low likelihood of PVD
- absent pulse indicates high likelihood of PVD
a doppler probe can be used to assess if there is significant blood flow present in the artery if pulses cannot be palpated
What is the main symptom of mild PVD?
claudication
this is limb pain (aching, cramping & tired feeling of the legs) upon exertion
most commonly occurs in the calves, but may also present in the feet, thighs, buttocks and arms
What is meant by the claudication distance?
How does this change as PVD progresses?
the distance that a patient can walk before they experience symptoms (pain)
as PVD progresses, the distance a patient can walk (claudication distance) is reduced
How is claudication / pain different for a patient who has severe PVD opposed to mild PVD?
- there is claudication / buttock pain at rest
- burning pain in the legs at night due to elevation (which reduces limb perfusion)
- burning pain relieved by hanging the legs over the side of the bed (v poor prognostic sign)
What other signs / symptoms should be looked out for in a patient suspected to have peripheral vascular disease?
- “punched out” ischaemic ulcers
- gangrene
- reduced / absent peripheral pulses
- skin atrophy (chronic disease)
- hair loss (chronic disease)
- cyanosis
- excessive sweating due to overactivity of sympathetic nerves
- erectile dysfunction
Where are “punched out” ischaemic ulcers usually seen?
When do they usually occur?
- usually on the toes and heels
- tend to occur after a localised traumatic event
- often painful, but diabetic and alcoholic patients may not have pain
How can gangrene be identified?
black necrotic gangrenous tissue often surrounds the punched out ulcer lesions
infection of these areas can occur (wet gangrene)
What is the name of the disease that leads to erectile dysfunction in patients with peripheral vascular disease?
Leriche syndrome
this is a type of PVD known as aortoiliac occlusive disease
it involves blockage of the abdominal aorta as it transitions into the common iliac arteries
What is the triad of symptoms associated with Leriche syndrome?
- claudication of the buttocks and thighs
- absent or decreased femoral pulses
- erectile dysfunction
the legs will also appear pale and cold
For what type of patient with PVD is amputation considered?
it may be necessary in patients with severe disease
it is usually only performed in patients with severe unremitting leg pain + gangrene
this is performed to prevent sepsis
How should amputation be performed to provide the best results for the patient?
- amputation should be performed as distally as possible
- ideally it should be below the knee, as this provides the greatest flexibility with prosthetic replacement limbs
- BUT it must be high enough to allow healing of the stump
- in many cases, above the knee amputation is likely to heal better
What medication is given prophylactically to patients who have an amputation and why?
gabapentin
this is used to treat phantom limb pain, which is very common
How is a diagnosis of peripheral vascular disease made?
After a diagnosis is made, where is the patient referred to?
diagnosis can be made on the basis of a suggestive history and examination, in conjunction with an ABPI <0.9
the patient is referred to the vascular team for further investigation, which typically includes a CT angiogram of the lower limb
What is ABPI?
Why is it used in the diagnosis of PVD?
ankle-brachial pressure index
it is a measure of the ratio of the blood pressure in the ankle vs. the arm
PVD affects the legs more than the arms, so it can be used as an indicator of reduced arterial blood flow in the legs
How is ABPI measured in the clinic?
What is a normal value and what value suggests limb ischaemia as a result of PVD?
- measure the BP in both arms and take the highest value
- measure the BP in both legs and take the highest value
(often, instead of a stethoscope, a Doppler ultrasound probe is used to measure the pressure over the posterior tibial artery - record the pressure when you hear the first “whoosh”)
- using only systolic values, divide the ankle pressure by the brachial pressure
A NORMAL VALUE IS >1
A VALUE OF <0.9 IS PATHOLOGICAL FOR LIMB ISCHAEMIA
the lower the number, the greater the degree of PVD
At what ABPI values will there be pain at rest and high risk of gangrene?
- pain at rest - ABPI is equal to or less than 0.6
- high risk of gangrene - ABPI <0.3 or ankle systolic pressure < 55mmHg
Why might false readings for ABPI be obtained in someone with severe atherosclerosis?
in very severe atherosclerosis, the vessels are incompressible
because of this, falsely high readings may be obtained
(e.g. ABPI > 1.3)
What blood tests should be performed in the investigations for PVD?
Why this combination?
- HbA1c
- lipids
- U&Es
- ESR / CRP - to exclude arteritis
- ECG - to check for cardiac involvement
- platelets & clotting
these blood tests form part of the investigation for diabetes