Aterial Occlusive Disease - Presentation and Investigation Flashcards
What are the common symptoms of intermittent claudication?
- Cramping pain on exertion
- Pain releved by rest
- Reproducible walking distance before onset of pain, although may deterioate over time.
What is the pathophysiology of intermittent claudication?
Athersclerosis causes narrowing of arteries and they can not supply enough blood when demand is high. This results in anaerobic respiration and releases metabolites which cause pain.
What are other diseases that may cause leg pain?
Osteoarthiritis, Neurogenic and Venous disease.
What is osteoarthiritis disease?
Caused by the lack of articulating cartilage in the joints. Pain comes on after variable exercise. Typically pain is relieved by sitting with weight off legs. Pain comes on walking often variable distances but can be at rest. Particullary occurs in hips
What is neurogenic disease
May be relieved by lumbar spinal flexion. Felt in hips, thighs or buttocks. Often more weakness then pain.
What is venous disease
A patient with history of proximal DVT can suffer in pain from their leg due to impaired venous return. Typically releived by rest and particularly elevation in contrast to peripheral arterial disease
What are the risk factors for development of peripheral arterial disease?
- Smoking
- Hypertension
- Diabetes
- Hypercholestoremia
What can be seen on examination with peripheral arterial disease?
- Loss of hair from legs and feet and there may be a shiny appearance on skin. Toenails may be brittle or slow growing.
- Skin may feel cooler or paler looking
- Examine for the presence or absence of peripheral pulse
How can you manage intermittent claudation?
- Manage risk factors and encourage exercise
- Managing risk factors - Smoking cessation, adoption of healthy diet, blood pressure and blood glucose should be measured and controlled appropiately. Each patient with peripheral arterial disease should be started on antiplatelet or statin to reduce further plaque formation.
- Exercise - Encouraged to walk daily
What is Critical limb threatening ischeamia?
Critical limb threatening ischaemia comes with leg pain and tissue loss.
What is the pathophysiology of critical limb threatening ischaemia?
Since arterys are narrowed, gravity becomes an important factor in helping to maintain peripheral blood flow. Patients describe this as a severe cramping pain which wakes them up during the night and is releived by dependance. Hanging legs down can worsen swelling in the tissue which can worsen skin breakdown and ulceration. This does not heal due to poor blood supply.
What are the Clinical presentation of critical limb threatening ischeamia?
- Will have reduced or absent pulses
- Monophasis or absent doppler signals
- Burgers test can be used to demonstrate arterial sufficiency.
What clinical tests should be done for clinical limb threatening ischaemia?
Blood test and ECG
What to prescribe patients with critical limb threatening ischaemia?
- Statins
- Antiplatelets
- Combination of painkillers such as analgesia (morphine)
- Any signs of ulcer can be treated with antibiotics
What imaging is used to see the pattern of disease in the arteries and possible intervention?
- CT angiogram of the lower limbs
- May need to arrange some tests of fitness to undergo surgery - Usually done by ECHO and PFT (pulmonary function test)
What factors need to be taken into consideration when deciding on the right course of action for vascular surgery?
- Pattern of disease
- Complexity
- Conduit
- Operative risk
- Patient wishes
How is critical limb threatening ischeamia managed?
- Conservatic/palliative: Management of symptoms only, generally for patients who are unfit for surgery
- Endovascular intervention:
- Opensurgery
- Hybrid procedures: combination of endovascular intervention and open surgery.
- Major limb amputation, above or below the knee , may be considered as a primary procedure if there is no revascularisation option or a secondary procedure if revacularisation option is not successful
What causes acute limb ischeamia? (pathophysiology)
Acute limb Ischaemia is caused by a sudden blockage in the normal artery which essentially cuts of the blood supply to tissue distal to this. When this happens the arteries beyond go into spasm to reduce oxygen demand which further reduces blood flow in the superficial capillaries. At this point the affected limb looks paler than normal
After acute limb ischeamia occurs, what happens in the next few hours?
In next few hours, release of mediators cause the spasm to relax, allowing the skin to fill with deoxygenated blood which creates purple/blue appearance. If you pressed against this area, you would see blanch and at this point the limb is still slavageble.
What happens when the ischeamia progresses ?
As the ishcaemia progresses, stagnant blood coagulates in the skin, giving a darker mottling which doesn’t blanch. This is called fixed staining. At this stage the ischaemia is irreversible.
What may happen if you try to revascularise the limb?
Any attempts to revascularis the limb will release lots of metabolites into the systeic circulation leading to acidosis, acute kidney injury, cardiac instability and potentially death.
What system is sued to classify acute limb ischeamia?
Rutherfords Classification.
Helps stratify the severity of symptoms and correlate them with the viability of the leg.
Tendresness of muscle on palpation is a very worrying sign and indicates the limb being threatened.
What is Acute-on-chronic limb ischaemia?
Blood has found alternative route as a result of underlying stenosis in the main artery
What symptoms will patients with acute-on-chronic limb ischeamia experience?
Patients with acute-on-chronic limb ischaemia have had experienced symptoms of claudication in the affected limb for some time.
