Ischaemia (Is-keem-E-a) is the term used in medicine when tissues do not have enough oxygen. Without oxygen tissues cannot function properly. In cases where there is a critical shortage of oxygen, the tissues begin to die.
Critical ischaemia in the leg can occur when the arteries in the leg have severe disease preventing blood from flowing to the foot and toes. For the arm it would be the hands and fingers that are affected.
Critical ischaemia causes pain in the foot and toes particularly at night when the patient is lying flat; when it is very severe the pain can be almost constant. Critical ischaemia can cause painful wounds or ulcers which do not heal over a period of weeks, and just get deeper. Occasionally, the poor blood supply can mean that one or several toes might develop black patches of dead tissue (gangrene). These symptoms and signs of critical ischaemia are an indication that, without treatment, the leg is unlikely to survive more than a few months. It is also strongly linked to severe artery disease elsewhere in the body such as the heart or in the brain. The risk of heart attack and stroke, and death, are greatly increased for patients with critically ischaemic limbs if left untreated.
Critical ischaemia usually requires some form of treatment to improve the blood supply so that more oxygen can be delivered to the ischaemic tissues. This is usually in the form of a bypass or, if it is possible, an angioplasty. If neither bypass or angioplasty is possible, or the tissues have died and cannot be saved, removal of the affected tissues by amputation may be the only, and best, option available.
It is vitally important that both patient and doctor work together to reduce the risk of heart attack, stroke and death as well as working to treat the ischaemic limb.