Healing diabetic foot ulcers

Mar 01, 2008, 5:00am

A clinician's physical assessment of a patient with diabetes should include evaluating the patient's vascular status, bony/structural deformities, footwear and foot sensation. Because diabetic patients may have sensory neuropathy, the nerves in their feet do not provide the alarms or triggers that tell them that there is possible trauma to the foot that could lead to ulceration.

Key Points

London, Ontario - Diabetic foot ulcers present a great challenge to healing, so preventative measures such as wearing proper footwear and vigilant monitoring of blood glucose levels is vital to avoiding the appearance of a diabetic foot ulcer, according to speakers here at the annual meeting of the Canadian Association of Wound Care (CAWC).

"Clinicians need to assess the whole wound and consider risk factors such as neuropathy," says Dr. David Haligowski, M.D., a Winnipeg, Manitoba, general practitioner with a special interest in woundcare.

"If there's neuropathy, there may be pressure that is not relieved," says Dr. Haligowski, who is also a clinical lecturer and physician resource at Winnipeg's University of Manitoba in the section of family medicine, department of internal medicine.

In addition to ongoing monitoring of diabetic control, clinicians need to take a comprehensive patient history that assesses complications and factors that can provoke skin breakdown or affect the healing of an ulcer.

Physical assessment

Physical assessment involves assessing vascular status, bony/structural deformities, and footwear and foot sensation.

Dr. Haligowski, a CAWC board member, notes that distal gangrene of the toes could occur in diabetic patients.

The presence of distal gangrene of the toes with a palpable pulse or adequate circulation may indicate microemboli from proximal atheromatous plaques.

In the presence of non-limb-threatening infection, clinicians should first administer topical antibiotics for diabetic foot ulcers.

If there is not a response to therapy, oral antibiotics should be considered, Dr. Haligowski says.

If a factor such as footwear is identified as the primary cause promoting skin breakdown, timely referrals should be made to ensure that the issue is managed, says Martine Albert, R.N., a registered nurse in Calgary, Alberta, a lecturer on woundcare issues and lower leg edema and management, and board member of the CAWC.

"Diabetic foot ulcers are largely preventable," says Ms. Albert, who has completed the International Interdisciplinary Wound Care Course.

"The most traumatic cause is usually footwear. There are measures that can be taken to avoid these ulcers," she says.

Ms. Albert says the neuropathy that diabetic patients often have, such as sensory neuropathy, means a loss of protective sensation in the foot.

Heightened plantar pressures due to motor neuropathy, together with sensory neuropathy, can lead to callus and ulcer formation.

"People with diabetes often have a problem with blood flow," Ms. Albert says. "If they have ulceration to the foot, that just compounds the problem in healing. Their white blood cells are not attacking bacteria and helping the body heal," she says.

Treatment

"You have to assess and remove the cause," Ms. Albert says.

"It may mean you have to offload the patient through using adaptive footwear, so the patient is not walking on that area of pressure. It may mean paring down calluses," she says.

In examining the ulcer, the clinician should look at the moisture balance and apply dressings if there is excessive drainage.

If there is an increased bacterial load, the clinician needs to determine if the load is local or systemic.

Depending on the assessment, the patient may need an oral or systemic antibiotic to address the bacterial load or infection.

If the clinician decides to debride a foot ulcer by removing slough, he or she needs to ensure there is adequate blood flow to the foot.

Without sufficient blood flow, the oxygen level will be inadequate to sustain the ability of the ulcer to heal, Ms. Albert says.

When a patient presents with a diabetic foot ulcer, it's vital to check the other foot for possible signs of an ulcer, Ms. Albert says.

"You need to insist the patient remove their footwear, so you can examine the other foot," she says.

"The other foot may not have an ulcer, but it may be on its way to developing an ulcer," Ms. Albert says.

According to the American Diabetes Association, 15 percent of all diabetic patients will develop a diabetic foot ulcer in the course of their disease.

"If you're looking at proportional rates, if the incidence of diabetes will go up, then the incidence of diabetic foot ulcers will likely also rise," she says.