More susceptible to medical complications, patients with diabetes require extra attention and intervention with skin assessment.

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iabetes mellitus affects more than 16 million people in the United States and comprises a large percentage of healthcare costs. Patients with diabetes receive about half of the nontraumatic lower-extremity amputations that occur in the US alone.¹ According to the American Diabetes Association (ADA), 11.4% of African Americans have diabetes and another third are undiagnosed for this disease.¹ Older individuals are also at a high risk for developing lower-extremity vascular and integumentary complications. It is estimated that 60–70% of diabetic foot ulcers are caused by diabetic neuropathy, and 15–20% are due to vascular compromise.¹ According to Buford, patients with diabetes who develop wounds and those who have chronically elevated blood glucose have less efficient healing responses.²
       Pressure ulcers have also gained attention as a healthcare issue. Despite renewed interest, pressure ulcers remain a major cause of death and morbidity, especially in those individuals with sensory loss and reduced mobility. Pressure ulcers affect 1–3 million people in the US with possible costs of up to $40,000 required for the medical management of each ulcer.³ High mortality rates and increased cases of medical litigation have been linked to the presence of pressure ulcers and the failure to prevent or heal them efficiently.³
       Complications, such as infections, contractures, limb loss, and depression, are associated with chronic wounds and further contribute to increased health costs.⁴ The patient with diabetes needs extra attention when it comes to skin assessment and intervention. Diabetes is a multisystem disease, and for that reason, examining patients’ feet will not be enough. A thorough skin assessment at multiple levels is essential.

Assessment Basics and Function

       Skin assessment decisions for a patient with diabetes symptoms depends on his or her present medical and functional status. If the patient is able to ambulate and is active, assessing issues related to proper shoe fit and protection of the weight-bearing surface of the foot is essential. On the other hand, if the patient is hospitalized or spending most of his or her time in a bed or chair, skin assessment should be directed to bony prominences that come in contact with the bed or chair surface.
       When assessing the ambulatory patient with diabetes, it is necessary to look at the quality of the skin on the feet and legs. Some patients may not be able to perform a proper foot self-inspection due to significant visual loss from retinopathy or a simple lack of mobility. Assessment includes feeling for temperature changes, looking for hemosiderin staining (brownish color staining under the skin), checking for normal capillary refill, looking for hyperemic changes, searching for any callous development on the plantar aspect of the foot, identifying fissures from dry, cracked skin, checking for fungal infection between the toes and on the plantar aspect of the foot, and inspection of the toenails. Careful assessment of shoes and footwear is important to reduce the risk of skin breakdown associated with improper fit. The clinician should document thick callous areas, fissures, bony prominences like bunions, and claw toes. Limitation in great-toe extension and ankle dorsiflexion should also be evaluated and documented. A physical therapist (PT) is a great addition to the wound care team and should be consulted and involved in the functional evaluation of at-risk patients.

Neuropathy and Complications

       Diabetic neuropathy affects the autonomic nerve fibers, causing a decrease in the secretion of oils that directly contribute to callous and dry skin problems. Motor-nerve fiber damage from poor glucose control can cause clawing of the toes due to weakness in the intrinsic foot muscles. The fat pad that protects the metatarsal heads on the plantar aspect of the foot migrates distally, leaving this weight-bearing area more vulnerable to shock, pressure, and shear from ambulation. Poor foot biomechanics can also cause callous formation or pre-ulceration. A thick callous under a metatarsal head needs to be shaved down by a podiatrist or qualified professional. If the pressure from a thick callous is significant, tissue damage may reach down to bone level. After callous debridement, offloading and proper dressing application, if required, should be addressed.
       A valuable tool used to assess diabetic foot ulcers is the Wagner Scale.⁵ This classification rates diabetic foot ulcers on a scale of 0–5. A grade of 1 has intact skin but a bony prominence and/or callous formation at high risk of ulceration. Grade 2 is a deep ulceration that penetrates tendon, bone, and joint capsule. Grade 3 is an ulcer that has associated osteomyelits and/or abscess. Grade 4 is an ulcer that has gangrene of the toes and or forefoot. Finally, a grade 5 has a large percentage of gangrenous tissue and cannot be saved.
       If a plantar ulcer is present, use of a custom healing shoe (ie, the OrthoWedge™ Healing Shoe, Darco International, Inc., Huntington, WV) with a plastizote and felt-dispersion innersole should be implemented. Other options to offload plantar ulceration include a diabetic boot or air cast. In noncompliant and very active patients, the total contact cast (TCC) is a good alternative for offloading (see Figure 1).

Figure 1

       A trained professional with expertise in TCC application must apply the cast. If the depth of the ulceration is to the bone, other tests, such as x-rays and bone scans, can be used to rule out osteomyelitis. X-rays are not conclusive until the osteomyelitis has progressed for 3–4 weeks. Therefore, if the wound probes to bone, a bone scan is recommended. The presence of a bone infection will usually require 6 weeks of intravenous (IV) antibiotics.
       Gait deviations like an abnormal foot strike can lead to limitation in the great toe and callous formation under the great toe or at the side of the toe depending on how the person ambulates. Irregular biomechanics like atypical pronation (a rolling in of the foot when ambulating) should be addressed in younger patients with diabetes through proper corrective orthotics and patient education. If these issues are addressed at an early age and on a yearly basis, many complications can be prevented.
       Patient education on Charcot foot deformities is also important. Discussing proper shoe wear and orthotic use as well as skin and foot inspections helps minimize the complications associated with the Charcot foot. The cause of Charcot deformities can be discussed by explaining the importance of proper blood glucose control. A trained clinician can perform infrared dermal thermography to assess temperature differences between the lower extremities. A difference greater than 3 degrees may indicate an active Charcot episode, and further tests need to be performed. If a patient has a swollen, red, hot lower leg, he or she should alert the clinician that he or she is diabetic and may need an x-ray. A TCC or diabetic air cast can be fitted to help stabilize a Charcot foot until it coalesces.

Assessment of Other Systems

       Assessment of the venous and arterial system should be included in the evaluation of the patient with diabetes. The importance of proper assessment should be stressed in a program of prevention. Such a program includes education to caregivers, patients, and family. The patient with diabetes who develops a pressure ulcer on his or her trunk or lower extremity is at greater risk of complications than the patient without diabetes. The patient with diabetes who develops an arterial or venous ulcer is at risk for amputation; therefore, early assessment can predict and possibly prevent these limb- and life-threatening issues.
       Upon assessment, a patient with venous insufficiency may present with weeping, edematous legs. A patient may only have edema with hemosiderin staining and/or dry, flaky, dermatitis of the lower limbs. This patient may benefit from an initial assessment of the ankle-brachial index (ABI) to ensure that the individual’s arterial status is sufficient to tolerate compression. A value of 1.0 is considered normal. For values between 0.8–1.0, compression can still be used. Some patients with diabetes may have abnormally high readings (ie, 1.3), indicating possible ischemia or hardening of the arteries. A trained clinician can perform an ABI with a blood-pressure cuff and Doppler ultrasound.
       Depending on the amount of drainage and bioburden within the wound bed, a dressing and type of compression can be selected. A 4-layer bandaging system like Profore® Multi-Later Compression Bandaging System (Smith & Nephew, Largo, Fla) or Four Flex™ 4-Layer Compression Bandaging System (Medline Industries, Inc., Mundelein, Ill) can be applied. When there is arterial involvement, a modified wrap may be needed, or compression may be contraindicated. All lower limbs should be liberally moisturized with a high quality moisturizing skin cream or barrier that contains dimethicone or zinc oxide. Two good choices include REMEDY™ Nutrashield (Medline), which substantially decreases transepidermal water loss (TEWL), and 3M™ Cavilon™ (3M Health Care, St Paul, Minn). Venous wounds tend to harbor a high degree of bioburden, which slows the natural healing process. Consider the use of an ionic silver dressing, such as a hydrogel or alginate, to wick away drainage and treat bacterial overload.
       When performing a skin evaluation, be especially aware of feet that are cool and have trophic changes. Trophic changes include shiny legs, decreased hair growth, thickened nails, decreased capillary refill, and hyperemic changes. A hyperemic response occurs when a limb loses blood supply due to leg elevation or poor shoe fit. The response when the foot is in a dependent position or the pressure (shoe) is off is an increase in redness to the areas where blood supply was decreased. Patients with arterial insufficiency may experience discomfort or pain when feet are elevated, such as in bed, and relief when the feet are dependent or dangling. They may also experience claudication pain when they are walking or exercising. Medication, continual assessment, revascularization surgery (if necessary), and foot protection are ways to prevent arterial ulcerations. An ABI evaluation may be of benefit to know the severity of the arterial compromise. If a wound is present and the ABI value is sufficiently high to indicate good healing potential, a proper dressing to provide a moist wound healing environment will promote tissue healing. These wounds tend to have a high bioburden, so choosing a safe, noncytotoxic, sustained-release antimicrobial like ionic silver is recommended. Smoking should be discontinued due to the severe effects of nicotine on the arteries in the extremities.
       Patients with diabetes often have other medical problems, such as coronary artery disease, peripheral vascular disease, renal dysfunction, and visual problems. Patients with diabetes who have medical procedures or hospitalizations are at increased risk due to their neuropathy. Lower-extremity and coronary artery bypass surgery, joint replacements, or amputations could increase the risk for wound development on pressure sensitive areas, such as the sacrum or ischial tuberosities. Other issues like prolonged surgery times can cause patients to have unrelieved pressure in the operating room. This can lead to pressure areas beginning on the distal limbs or sacral area. Skin assessment should be performed in the recovery room where early intervention can begin, especially with the patient with diabetes. Pressure relief should be considered along the entire healthcare spectrum, including the operating room table where substantial damage can take place. Special assessment will be needed for any patient with impaired mobility (ie, patients with strokes, spinal-cord injury, progressive neurodegenerative diseases, etc.). Identifying at-risk patients is vital. Using a risk assessment tool, such as the Braden Scale, is helpful (see Table 1).

Table 1

Positioning Issues

       Over time, a patient with hemiplegia who has suffered a stroke may develop tightness in his or her involved lower extremity. A position of hip flexion, external rotation, and abduction and knee flexion will increase the chance of skin breakdown under the lateral portion of the heel, malleoli, or forefoot.
       Looking at the appropriateness of the bed for the involved patient is important to prevent devastating consequences. Pressure redistribution is essential. Patients who are at risk or have developed stage I breakdown need, at minimum, an aggressive turning schedule. Consider altering the turning schedule and include range-of-motion (ROM) interventions for patients at risk of developing contractures. High-density and multidensity foam mattresses and other group-1 type surfaces can easily replace traditional innerspring mattresses, which tend to increase pressure, especially on bony prominences. In high-risk patients, a group-2 type support surface like a low-air-loss mattress replacement should be chosen.
       If the patient has fair trunk mobility with poor lower-extremity movement due to surgery, disability, or dementia, educate caregivers in pillow bridging and/or use of heel or positioning systems to prevent excessive heel and foot pressures. A minimum of 4 pillows is necessary to effectively position a recumbent patient. Products like the Heelift® by DM Systems, Inc. (Evanston, Ill) may help with offloading and distributing pressures off both the heels and malleoli.
       According to 1 study,⁶ suspending the heel completely is more effective than cushioning it. Prevention of heel ulcers is of utmost importance in patients with diabetes and requires continual risk assessment and proper positioning. The bottom line for prevention of heel pressure ulcers is not synonymous with any 1 product but with ongoing assessment of the heels and diligence regarding turning and positioning of the patient. Simple offloading with a pillow can also prove successful.
       Be sure to assess sitting posture of high-risk patients. Sitting posture can be affected by tightness in hip and knee muscles. Patients can experience shearing and direct pressure when sitting in devices like geri-chairs or improperly fitted wheelchairs. The amount of time that a kidney patient sits in dialysis is additionally significant. This, combined with the fact that a patient on dialysis usually has sacral edema, makes the risk even higher. Therefore, those patients with diabetes who have renal dialysis 3 times a week and are at high risk require pressure redistribution surfaces to decrease the likelihood of skin breakdown on the trunk and lower extremities.
       Assessing the patient’s environment (home, long-term care facility, etc.) to ascertain appropriateness of equipment, such as a proper elevated position for those using a recliner, is also crucial in preventing pressure ulcers. A standard recliner chair works unless the patient is having difficulty with transfers. When transfer is difficult, a PT consult may be needed. A motorized lift chair is helpful for patients with these issues. For patients at risk for sacral or ischial breakdown, a pressure-relief cushion is a good first step.
       When assessing wheelchair position, ensure that patients sit with their hips, knees, and ankles at approximately 90-degree angles. Footrests must be at an appropriate height, and the patients’ feet should be protected and rest comfortably on the footplates. If the feet are not well protected, undetected pressure from the footplates can occur, especially in patients with diabetes who have sensory neuropathy. If the individual is a foot-propeller, proper seat-to-floor height should be measured in order for the patient to achieve sufficient foot strike and pull-through. Wheelchairs that have sling-seat upholstery and fold up should have solid seat inserts under the pressure-relieving cushion. Without it, poor positioning can result from the chair upholstery sagging and eventually affect mobility and range of motion.

Assessment, Education, and Prevention

       Patients with diabetes need to be screened with careful skin inspection. Once screened and assessed, targeted education to those at risk should include diabetic foot risk factors, skin care and wound prevention, and proper shoe/orthotic wear for optimal foot protection. Strict glucose control is encouraged to slow nerve damage associated with diabetic neuropathy. Individuals should be educated on what they need to know if they are hospitalized or have limitation in movement to prevent pressure ulcers on the trunk and/or the lower extremities. A team effort and assessment by physicians, therapists, dieticians, nurses, wound care clinicians, aides, family members, and the patient is needed. With this knowledge and good skin assessment, healthcare practitioners can work together with patients and their families to help decrease the morbidity rate and health cost related to diabetes.