Peripheral Vascular Disease Flashcards
When does intermittent claudication occur?
When there is insufficient blood flow to the muscles in the legs during exercise
What is intermittent claudication?
Ischaemic pain in the legs exacerbated or brought on by exercise due to the muscles requiring more oxygen than the vasculature can supply
What are the four main pulses in the lower limbs?
- Femoral 2. Popliteal 3. Posterior tibial 4. Dorsalis pedis
Which two general approaches to investigation could be taken for suspected lower limb ischaemia?
- Non-invasive investigation 2. Invasive investigation
Give two examples of non-invasive investigation in relation to lower limb ischaemia
- Measurement of ABPI (ankle-brachial pressure index) 2. Duplex ultrasound scanning
Give three examples of invasive investigation in relation to lower limb ischaemia
- Magnetic resonance angiography 2. CT angiography 3. Catheter angiography
What is angiography?
Radiography of blood/lymph vessels after introduction of a radiopaque substance (contrast).
Why is a normal ankle-brachial pressure index (ABPI) very close to 1?
ABPI is calculated by dividing ankle blood pressure over brachial pressure. Ideally, blood pressure should be the same at both locations (giving ABPI of 1) In PVD, blood flow is reduced to the lower limbs so blood pressure is lower, which gives a lower ABPI
What is the normal ABPI range?
0.9-1.2
What is the ABPI range for someone with claudication
0.4-0.85
What is associated with diabetes that can lower ABPI?
Calcified vessels - lowers peripheral artery blood pressures
How does exercise impact ABPI?
Normally it will increase, but in patients with claudication it will decrease
Which two elements are incorporated into duplex ultrasound scanning?
- Grayscale - visualises structure, plaques and cross sections of narrowed vessles
- Colour - Allows for visual representation of blood flow
What does magnetic resonance angiography allow viewing of?
Occulsions and aneurysms
How does CT angiography work?
A range of X-rays are beamed froma rotating device to create a 3D image.
Contrast is added to vessels