The increasing global incidence of diabetes brings with it an increase in diabetes complications. Those affecting the feet are probably the most feared. These complications, such as foot ulcers, are very serious, extremely costly and can be devastating if they end in amputation.
The complications of diabetes, such as foot ulcers, can be prevented or delayed when people with diabetes play an active role in their own care and education about their condition. Education helps in the early recognition of complications and the ability to act appropriately.
What causes foot ulcers?
The most common causes of diabetic foot ulcers (DFU) are nerve damage, poor blood supply, poor footwear, foot deformities and injury.
When nerves are damaged, it is known as peripheral neuropathy. There is a reduced feeling, or feeling may be absent altogether.
Changes in the blood vessels will reduce the volume of blood delivered to a specific part of the body, in this case the feet. This is known as peripheral vascular disease. Both peripheral neuropathy and peripheral vascular disease can be present at the same time.
When feeling is reduced or absent, a person with diabetes may injure his or her foot without being aware of the injury until it presents with: an infection, moisture oozing from the foot, odour or swelling. Sometimes family members become aware of these symptoms and then investigate.
Neuropathy alters the speed of blood flow in the foot and wasting of the muscles. It leads to weakness of the foot and changes the shape of the toes and leads to abnormally high pressures on the foot.
Good blood supply to the feet keep the tissues and muscles strong and healthy. If the supply is inadequate, the foot becomes more susceptible to injury and healing is also prolonged.
Most foot ulcers are caused by poor footwear. Foot ulcers develop where pressure is the highest. Hard skin or callus is a sign of pressure and walking on callus increases the pressure on the hard skin – like walking on a stone. The neuropathic foot won’t feel the pressure or the pain.
The importance of feet self-examination cannot be overemphasised. This is best done daily, and if abnormalities are observed, action must be taken.
Healthcare professionals can assist the diabetic patient by doing feet inspection and education at the same time. If one foot has an injury or ulcer, inspection of the healthy foot is also important.
How to spot foot ulcers
A foot ulcer may present as a dark spot that resembles a splinter under the skin. Once the hard skin is removed, the ulcer is exposed.
Foot ulcers may look like small holes surrounded by a halo of pale skin. When the hole is examined, a larger ulcer is found that was hidden under the skin. This is known as undermining.
Undermining can be compared to a table that has a solid surface on the top, with a large open space underneath.
Examination and treatment of these lesions are best done by trained healthcare professionals. No bathroom surgery.
Once diabetic foot ulcers have been diagnosed, a wound nurse who specialises in advanced wound management can assist with wound care and the correct selection of treatment.
The choice of dressing must promote wound healing and be appropriate for a diabetic foot. It must treat infection, absorb exudate (moisture oozing from a wound), protect the surrounding skin, may have to treat devitalised or dead tissue, and must be soft enough to not add pressure to the area.
Other modalities that can be used to enhance wound healing:
- Spray application of haemoglobin.
- Subatmospheric Pressure Therapy – negative pressure wound therapy also known as Vacuum Assisted Closure (VAC)).
- Total Contact Casting (TCC).
- Application of protease modulators.
- Protein Rich Plasma Therapy.
Blood sugar control
Blood sugar control is essential to assist wound healing. The body’s ability to fight infection is reduced in a high sugar environment because the white blood cells become ‘lethargic’ and slow to fight invading microorganisms. If an infection is suspected, it is best to consult a doctor for antibiotics as soon as possible.
Multi-disciplinary team approach
The best approach to help heal diabetic foot ulcers is to have a multi-disciplinary team. The wound nurse will treat the foot ulcers while the vascular surgeon will assess and treat the blood supply. The vascular surgeon/general surgeon will clean the wound by removing dead tissue so that viable tissue is exposed and healing can be quicker. The podiatrist will look at and treat any abnormal shape of the foot or problems with the gait. An orthotist can prescribe or make footwear for the diabetic foot. And, the diabetologist and the diabetes nurse educator manages blood sugar control.
Diabetic foot ulcers can be prevented, but the time to act is now. Once diabetes has been diagnosed, it is best to have an assessment done by the various diabetes professionals in the team to establish a baseline to work from. Having a baseline means including the person with diabetes because various goals can be set to work towards. Such a goal may be to normalise blood sugar levels to encourage healing and to prevent more complications.