Presentation
Acute ischaemia refers to the sudden onset of a lack of blood flow to the limb. It occurs more in the elderly and poses a serious threat to the limb and to the patient's life.
Classically the presentation is said to be the 6 'P's:
 | Pain - this is severe and may be relieved somewhat by dangling the leg out of bed. The muscles affected may be tender or painful on passive movement of the foot. |
| Pallor - the limb may be pale or mottled. If the mottling does not blanch on pressure the limb is probably beyond saving. |
| Pulseless - pulses which were normally present will be missing. |
| Paraesthesia - loss of sensation is a serious sign of severe ischaemia indicating that immediate action is needed. |
| Paralysis - this can be due to severe muscle damage or to nerve damage as a result of the ischaemia. Like paraesthesia it indicates a need for immediate action. |
| Perishing with cold - this is variable depending in the temperature in the room. The affected limb will be cooler than the normal one. The level of coldness and mottling can indicate the level of blockage in the arterial tree. |
Examination of the patient will give an idea of the level of blockage in the arterial tree. Missing pulses, level of coldness and mottling all give clues. As mentioned above paralysis, paraesthesia and blanching of mottling all give an idea of the severe of ischaemia and indicate the need for immediate action.
The picture below shows an unfortunate patient in whom both legs have been affected. You can see that the feet are pale and the lower legs mottled.
The mottling extends to the thigh indicating blockage fairly high in the arterial tree.
The arms can also be affected. The picture below shows the patient's left hand is pale - the patient had difficulty using it.
