Inspect, feel the pulses, then Buerger's test and the pressure index
Expansion
Look: colour, hair loss, shiny atrophic skin, thickened nails, ulcers at pressure points, gangrene, amputations, scars from previous bypass, and between the toes and on the heels.
Feel: temperature comparing sides, capillary refill, and the pulses.
Pulses, in order
- Femoral, at the mid-inguinal point, with radiofemoral delay for coarctation
- Popliteal, with the knee flexed and both thumbs on the tibial tuberosity
- Posterior tibial, behind the medial malleolus
- Dorsalis pedis, lateral to the extensor hallucis longus tendon, and absent in about 10 per cent of normal people
- Abdominal aorta, for an expansile mass
Auscultate for bruits over the aorta, iliac and femoral arteries.
Buerger’s test: elevate the leg and note the angle at which it pales. Below 20 degrees indicates severe ischaemia. Then hang the leg down; a slow return with reactive hyperaemia, a dusky red colour, is positive.
Ankle brachial pressure index
| Value | Meaning |
|---|---|
| 0.9 to 1.3 | Normal |
| 0.5 to 0.9 | Claudication |
| Under 0.5 | Critical ischaemia |
| Over 1.3 | Falsely high, calcified vessels |
Critical limb ischaemia is rest pain for over two weeks, tissue loss or gangrene, with an ankle pressure below 50 mmHg, and warrants urgent revascularisation. Rest pain relieved by hanging the leg out of bed is the classic history.