So you think your patient has chronic limb arterial insufficiency.

You decide to the Buerger’s test

– with the patient supine, ask them to slowly lift the legs up (above the level of the right atrium) and look for colour change in the feet – if it occurs when the legs are elevated at an angle of less than 20 degrees it indicates severe ischaemia; in a limb with a normal circulation the toes stay pink, even when the limb is raised by 90 degrees

– the ask them to exercise the feet ~ 30 sec and look for colour change

– then ask them to sit up and measure the time to return of normal colour – if it’s > 20 sec, it is sign of ischaemia