arterial insufficiency in the lower limb and foot

arterial insufficiency in the lower limb and foot

lower-limb ischaemia characterized by nine P signs: pain; pallor of skin; puffiness (oedema); perishing cold; pulselessness; paraesthesia (reduced sensation or numbness); paralysis and difficulty in movement; poor or reduced peripheral healing; proneness to painful tissue breakdown with acutely painful, slow-to-heal ulceration; the more marked the P signs, the more profound the arterial dysfunction and the more likely the presence of arterial occlusive disease (Table 1)
Table 1: Clinical effects of arterial insufficiency on the foot and lower limb
CharacteristicComment
PulsesDifficult-to-palpate/reduced/absent foot + limb pulses (femoral, popliteal, anterior tibial, posterior tibial, dorsalis pedis, peroneal pulses)
Slow capillary refill>5 seconds delay before normal colour returns to toe pulp, following release of digital pressure
Skin temperatureColdness/clamminess of toes/distal feet
Raynaud's or peripheral vascular disease patients show skin temperatures of <25°C
Skin colourLoss of normal skin colour, e.g. marked/prolonged pallor, cyanosis, cold redness
Persistent dusky cyanosis of cold, oedematous limb that becomes pallid on elevation to horizontal indicates arterial compromise/poor capillary perfusion
Tissue toneReduced tissue tone; thin skin with fissuring, especially at heel perimeter; dryness/fragility of skin (due to atrophy of sweat glands); decrease in bulk/resilience of plantar fibrofatty pad
Nails and hairsNail dystrophy, poor growth, Beau's line formation; hair loss
Intermittent claudicationIntermittent claudication may only occur under stress, i.e. when climbing stairs/walking up hill
Rest painRest pain in leg and/or foot when limb is horizontal, e.g. in bed; patient uncomfortable when sitting with feet up
Poor healing and tendency to ulcerationMarked reduction in distal healing. Severely painful areas/devitalized tissue/frank ischaemic ulceration/dry gangrene at tips of toes/bony prominence (e.g. styloid process, malleoli)
Doppler soundsMonophasic; audible bruits where arterial flow is turbulent (due to atherosclerotic plaques/stenosis)
Ankle-brachial index (ABI)< 0.7
Buerger's angle< 70°
OedemaThe patient is unable to tolerate legs in a horizontal position due to rest pain, so may sleep sitting up, in an armchair, rather than going to bed - as a result, legs are always dependent and fluid accumulates in distal tissues
NeuropathyLoss of sensation/numbness/inability to move digits