Diabetes mellitus is a chronic medical condition affecting people of all ages worldwide. If left uncontrolled, the disease is debilitating. Diabetes can lead to multi-systemic dysfunction, poor wound healing, and limb loss. Consequently, wound care professionals must remain up to date in improved treatment and prevention strategies to minimize unwanted diabetic limb complications.  

Diabetes, Poor Wound Healing, and Diabetic Limb Loss: What’s the Correlation?

A 2020 Report from the CDC,shows that up to 35 million people of all ages in the United States suffer from either Type 1 or 2 Diabetes mellitus with a significant number experiencing diabetic limb complications at some point. How does diabetes impede optimal wound healing and lead to other devastating sequelae like limb loss? The answer lies in the pathophysiology of the illness.

Pathophysiology of Diabetic Wound Healing

Diabetes is characterized by dysfunction in either the production or utilization of insulin needed to regulate blood glucose levels. This disruption in the normal physiological response to rising blood glucose results in persistently elevated sugar levels or hyperglycemia.

The implications of persistent hyperglycemia in wound healing are outlined below:

●     Diminished white blood cell function

●     Poor circulation/tissue perfusion

●     Neuropathy with increased risk for unnoticed injuries

Diminished White Cell Function

Persistently elevated blood glucose levels negatively impact the functioning of white blood cells that play a key role in the body’s defense against bacteria and other pathogenic organisms. All wounds require an environment free of pathogenic microorganisms to heal satisfactorily. The diminished ability of white cells in patients with poorly controlled diabetes to fight off invading microorganisms will drastically slow the rate of wound resolution. The result is wound chronicity, necrosis,gangrene, and eventual limb loss.

Poor Circulation/Tissue Perfusion

Uncontrolled diabetes is associated with the pathological narrowing of blood vessels. Blood vessel damage will lead to poor circulation of blood-borne nutrients and oxygen needed for tissue repair. Diminished tissue perfusion will slow down injury resolution, and in more severe cases lead to tissue death. Diabetic limb injuries are high-risk injuries due to the compromise of the blood flow reaching them.

Neuropathy with Increased Risk for Unnoticed Injuries

Nerve damage (neuropathy) is a well-recognized complication of prolonged hyperglycemia. Persons with diabetes neuropathies may experience abnormal sensations and numbness in their feet.Loss of sensation in these areas places them at a higher risk of sustaining injuries they remain oblivious of. The resultant poor wound care will prolong wound healing and lead to undesirable outcomes including eventual limb loss.      

Extrinsic Factors Influencing Wound Healing in Diabetic Limbs

Apart from the effects of persistent hyperglycemia in diabetic limb wounds, external factors also play a critical role in the rate of injury resolution.

The most commonly recognized external factors include:

●     Medication compliance

●     Access to expert wound care services

●     Socio-economic status

Medication Scaling and Compliance

Diabetes is a chronic medical condition that requires life-long medication use in the form of oral hypoglycemic agents and insulin. To achieve satisfactory blood glucose control,effective doses of the medications need to be titrated to individual patient requirements. Further, patients and their caregivers need to adhere to the prescribed medication regimens to obtain control.

In cases where medication compliance is poor, blood sugar levels will soar and persistently high levels will result in poor wound healing, tissue death, and limb loss.

Access to Expert Wound Care Services

Diabetics who sustain limb wounds require careful and close monitoring by wound care professionals to prevent injury chronicity and limb loss complications. In underserved communities, lack of access to licensed wound care professionals is associated with higher rates of diabetic foot complications and amputations.

Socio-economic Status

This is closely linked to the earlier mentioned extrinsic factors. Studies have associated poorer outcomes in diabetic limb wounds with persons with lower socioeconomic standing. These subsets of individuals are least likely to be able to afford the medications,and expert wound care services needed when they sustain limb wounds.Consequently, slower wound resolution with poorer long-term outcomes is common.

Diagnosing Diabetic Limb Injuries

Diabetic limb injuries are quite easy to identify in patients who have an established diagnosis of diabetes mellitus. In many instances, affected individuals will have a history of persistently elevated blood sugar levels with poor or non-existent compliance with medications.

Diagnostic studies are often recommended to help assess the extent of tissue injury and also guide interventions. Critical clinical, laboratory and radiological studies relevant to diabetic limb conditions include:

●     Peripheral nerve testing

●     Skin and nerve tissue biopsies

●     Ankle-brachial pressure index testing

●     Wound cultures

●     Random, fasting blood glucose testing, and HbA1C analysis

●     Nerve conduction studies

●     Electromyography

●     Computerized tomography scanning

●     Magnetic resonance imaging

●     Doppler ultrasonography

Treatment Strategies for Professionals Managing Diabetic Limbs

The management of diabetic limbs is based on the careful and optimal resolution of already present wounds while preventing the onset of new injuries/ulcerations. Interventions are usually tailored to individual patient needs and conducted by a team of wound care professionals from various disciplines. Effective wound care can only be achieved by cooperation between wound care professionals and the patients they care for.

Some key treatment strategies are discussed below.

Local Wound Care

Wound reviews, tissue debridement,and wound care dressings are critical to optimizing the wound environment for rapid healing/injury resolution. Diabetic limb ulcers and other injuries will benefit from daily dressings and other appropriate diabetic limb nursing care.

Saline dressings maintain a moist wound environment, manage excess wound exudate, and inhibit wound colonization by bacteria. Hydrocolloid dressings are useful in dry wounds while alginate and impregnated gauze dressing can effectively manage highly exudative wounds.Depending on the amount of necrotic tissue noted within and around the wound margins, debridement sessions can be scheduled on a daily, weekly, or monthly basis.

Diet and Lifestyle Modification

Persons with diabetic limb wounds will benefit from modifications to their usual diets. Consulting with a dietician is highly recommended. A diabetic person can still experience healthy, nutritious, and tasty meals like everyone else. Meals should include plenty of fruits, vegetables, and whole grains. Foods with high calories and saturated fats are to be avoided as much as possible.

Further, integrating mild to moderate physical exercises in daily activities is a very useful wound care strategy. Physical exercise will help improve blood circulation in affected limbs thus increasing oxygenation and nutrient supply to wound sites. Shedding weight will also help improve long-term glycaemic control in obese persons.

Antibiotic Therapy

In several cases, persons with poorly healing diabetic limb wounds will require antibiotic therapy. These injuries typically provide a hospitable environment for bacteriological colonization and the onset of soft tissue infection. In cases where there are obvious signs of infection, empirical antibiotics should be started with prescriptions modified once wound culture guidance is obtained.

Strict Glycaemic Control

There is a well-established link between poor blood sugar control and slow wound resolution in diabetics. To achieve a steady glycaemic state, reduce the occurrence of new complications and experience faster wound healing rates, patients must adhere to pharmacological treatments. Optimal levels of blood glucose can be obtained through the consistent use of appropriate doses of insulin injections or oral hypoglycaemic medications.

Surgical Intervention

All patients with diabetic limb injuries should undergo surgical evaluation by vascular and podiatric surgeons to determine the extent of the damage. This will guide decisions on extensive debridement, bony/vascular reconstructive surgery, and soft tissue defect correction.

Other Treatment Measures

There are various other treatment options with useful benefits in managing diabetic wounds include:

●     Biologic wound dressing substitutes

●     Topical recombinant growth factors

●     Hyperbaric oxygen therapy

Diabetic Limb Preservation:Essential Wound Care Team Members

Optimal care for diabetic limbs requires the harmonious functioning of a multi-disciplinary team of wound care experts. Each team member plays a distinct role in providing wholesome and effective care necessary to achieve the best possible outcomes. Crucial team members include:

Diabetic specialists, diabetic nurses, podiatrists, general and vascular surgeons, interventional radiologists, microbiologists, physical therapists, psychologists, health educators, and shoemakers. The comprehensive care provided by these specialists will significantly reduce the rates of limb loss associated with chronic diabetic limb disease.

Useful Tips for Managing Diabetic Limbs

Outlined below are some useful tips for preserving diabetic limbs and preventing the occurrence of further damage.

●     Daily self-examination of limbs in individuals at risk of diabetic limb injuries. Examinations should focus on noting changes to skin color, temperature, callus formation, and development of ulcers. Changes should be reported to wound care experts as soon as detected.

●     Use of proper protective footwear is highly recommended especially in persons with loss of sensation in their limbs.Persons with diabetic limbs must avoid walking barefoot at all times.

●     Regular appointments with podiatrists to monitor feet for calluses and ulcerations.

Compliance with medication regimens and dietary modifications to keep blood sugar levels within an acceptable range.