The diabetic foot syndrome deals with changes appearing on the lower extremities in patients with diabetes.
The cause of the diabetic foot syndrome are changes in the blood vessels (ischemia), and damage to the nerves (neuropathy). Deterioration of vascularisation and innervation in diabetic patients usually progress simultaneously, but only one of these changes is dominant. The dominant factor determines the type of the diabetic foot syndrome, and so can be distinguished: ischemic diabetic foot syndrome or neuropathic diabetic foot syndrome.
Figure: diabetic foot syndrome – classification as for the dominant factor
Peripheral neuropathy i.e. peripheral neuritis - is one of the complications of prolonged hyperglycemia and affects both somatic and autonomic nerve cell projections in both legs. The patient has reduced sensation of pain, temperature and touch in the affected leg, and since feels no pain after an injury or compression, the skin is often damaged and ulcers are formed, which are often not noticed early enough and thus start to be treated too late. Late detection of the ulcers may be then too advanced to be successfully treated.
Motor neuropathy causes loss of muscle and foot tendons and, consequently, destruction of the joints. This in turn leads to the concentration of workload on a few small areas of the plantar surface, and further to the formation of callus. The final step of these changes is foot deformation.
Angiopathy i.e. damage to blood vessels – blood supply disorders are characterised by abnormal blood flow in the legs especially tibial and fibular artery. Uncontrolled diabetes favours the development of arterial diseases. The control of blood glucose content is one of the prevention ways, it is also a precondition for starting the process of wound healing.
Therefore, we can distinguish:
- neuropathic foot ulcers, which constitute two thirds of all diabetic foot ulcers
- angiopathic foot ulcers (~ 10%)
- mixed foot ulcers (~ 25%)
- People with diabetes mellitus.
- People with undiagnosed diabetes!
This disease affects mostly people with type II diabetes i.e. the one not requiring insulin injections.
The complication in for of diabetic foot is present in approximately 20% of hospitalised patients because of diabetes, and is the cause of 50% of all limb amputations performed in surgical wards.
Neuropathic diabetic foot
The predominant symptoms:
- loss of sensation to touch, pain and temperature
The patient does not feel the presence of a malicious stimulus such as a cut, burn, hurting by wearing tight shoes, the presence of a foreign body in the shoe. Insensitivity to pain is the basic element causing the formation of ulcers on the foot sole. The neuropathic diabetic foot is warm, with preserved flow in the arteries, but the foot joints and bones are deformed.
In some patients the changes appear in the joints and are formed by gradual destruction of small joints of the foot which results in considerable distortion of the feet. It is necessary then to wear special shoes made upon an individual order. Wearing normal ill-fitting shoes very often leads to the formation of ulcers.
Ischemic diabetic foot syndrome – angiopathic
The predominant symptoms:
- increased sensitivity to pain
The main symptoms are: pain intensifying usually at night, often accompanying painful muscle cramps, tingling or numbness in the leg.
Depending on the level of stenosis and occlusion of arteries in the lower limb, necrosis appears on different areas of the foot.
The most severe form of the disease is the closure of large arteries in the lower limb above the knee. This results in tissue necrosis in the foot, and sometimes also in the lower leg. Necrosis affects mostly toes. Ischemic diabetic foot is characterised by preserved innervation while simultaneous impaired blood supply in the limb.
An untreated diabetic foot syndrome leads to the amputation of the limb.
In patients with diabetic neuropathy ulcers are located primarily in areas of repeated injuries and affect usually the plantar surface of the foot around the metatarsal bone, heel and toes. Usually the neuropathic ulcers are painless.
In addition, as a result of neuroarthropathic disturbances, the foot is distorted in a characteristic way – grooved feet, mallet toes, changed way of walking, and in over-loaded points in the calluses (corns) are formed that can later cause non-healing wounds and ulcers.
In the case of ischemic diabetic foot chronic hypoxia causes that the foot begins to die – it swells, ulcers, necrosis and cracks appear, nails get deformed and soft tissues disappear and the whole foot becomes blue.
A specialist in the field of diabetes, surgery (including vascular surgery) and orthopaedics is the competent person for ordering treatment. Nurses also actively participate in the therapy. The most important thing is to keep sugar level in blood in optimal physiological limits.
The treatment is both causal and local.
Wounds are surgically debrided, narrowed blood vessels are unblocked, various vascular grafts are used to allow bypass clogged arteries which improves blood flow in the foot. Along with the surgery blood sugar in the body is controlled and medicaments facilitating the treatment are dosed. In addition to insulin and antibiotics the patient receives medicines that improve blood circulation in the limbs, reduce blood viscosity, enabling to reach the ischemic structures, improve wound healing and scarring. Also appropriate diet is recommended.
It most essential in the prevention of diabetic foot development is the proper treatment of diabetes, the control and maintenance of a normal blood sugar level.
After diagnosing diabetes the patient should:
- quit smoking
- gently and carefully take care of the feet
- systematically control the circulation and innervation of the feet
If there are foot lesions, early physician intervention often prevents the need of amputation of the lower limb.
Everyday foot care in people with diabetes should consist of:
- everyday observation – controlling blood flow and sensation, washing in warm (not hot) water, gentle and careful drying – especially the space between toes
- care for nails – regular trimming (but not too short)
- careful selection of shoes – should be sufficiently wide, the right size (patients with neuropathy, due to the worsening of sensation tend to buy too small shoes, smaller than the ones worn so far), the heel should be low and wide, shoes with laces are recommended
- before putting on shoes the patient should check whether inside there are no sharp objects, outstanding seams or rolled inserts
- wear non-binding and non-elasticated socks made of natural fibres (too tight socks can impede blood circulation)
- protect the foot against excessive: soaking , exercises or heating (for example by means of an electric blanket or other energy sources)
- do not use ointments on foot corns – unless your doctor tells otherwise
Any observed changes in the foot, such as swelling, colour change, loss of sensation should be consulted as soon as possible with a doctor.
Even minor cuts, skin cracks and wounds cannot be ignored and always need to be secured with sterile dressings and shown to the doctor during control visits. If there is no progress in the healing it is recommended to urgently consult the doctor.