FOOT AND LEG PROBLEMS
From 50% to 75% of lower extremity amputations are performed on people with diabetes. More than 50% of these amputations are thought to be preventable, provided patients are taught foot care measures and practice them on a daily basis (ADA, Preven-tive Foot Care in People With Diabetes, 2003). Complications of diabetes that contribute to the increased risk of foot infections include:
• Neuropathy: Sensory neuropathy leads to loss of pain and pressure sensation, and autonomic neuropathy leads to in-creased dryness and fissuring of the skin (secondary to de-creased sweating). Motor neuropathy results in muscular atrophy, which may lead to changes in the shape of the foot.
• Peripheral vascular disease: Poor circulation of the lower ex-tremities contributes to poor wound healing and the devel-opment of gangrene.
• Immunocompromise: Hyperglycemia impairs the ability of specialized leukocytes to destroy bacteria. Thus, in poorly controlled diabetes, there is a lowered resistance to certain infections.
The typical sequence of events in the development of a dia-betic foot ulcer begins with a soft tissue injury of the foot, for-mation of a fissure between the toes or in an area of dry skin, or formation of a callus (Fig. 41-10). Injuries are not felt by the pa-tient with an insensitive foot and may be thermal (eg, from using heating pads, walking barefoot on hot concrete, or testing bath water with the foot), chemical (eg, burning the foot while using caustic agents on calluses, corns, or bunions), or traumatic (eg, injuring skin while cutting nails, walking with an undetected for-eign object in the shoe, or wearing ill-fitting shoes and socks).
If the patient is not in the habit of thoroughly inspecting both feet on a daily basis, the injury or fissure may go unnoticed until a serious infection has developed. Drainage, swelling, redness (from cellulitis) of the leg, or gangrene may be the first sign of foot problems that the patient notices. Treatment of foot ulcers involves bed rest, antibiotics, and débridement. In addition, con-trolling glucose levels, which tend to increase when infections occur, is important for promoting wound healing. In patients with peripheral vascular disease, foot ulcers may not heal because of the decreased ability of oxygen, nutrients, and antibiotics to reach the injured tissue. Amputation may be necessary to prevent the spread of infection.
Foot assessment and foot care instructions are most important when caring for patients who are at high risk for developing foot infections. Some of the high-risk characteristics include:
· Duration of diabetes more than 10 years
· Age older than 40 years
· History of smoking
· Decreased peripheral pulses
· Decreased sensation
· Anatomic deformities or pressure areas (eg, bunions, calluses, hammer toes)
· History of previous foot ulcers or amputation
Teaching patients proper foot care is a nursing intervention that can prevent costly, painful, and debilitating complications. Pre-ventive foot care begins with careful daily assessment of the feet. The feet must be inspected on a daily basis for any redness, blis-ters, fissures, calluses, ulcerations, changes in skin temperature, and the development of foot deformities (ie, hammer toes, bunions). For patients with visual impairment or decreased joint mobility (especially the elderly), use of a mirror to inspect the bottom of the feet or the help of a family member in foot in-spection may be necessary. The interior surfaces of shoes should be inspected for any rough spots or foreign objects.
In addition to the daily visual and manual inspection of the feet, the feet should be examined during every health care visit or at least once per year (more often if there is an increase in the pa-tient’s risk) by a podiatrist, physician, or nurse (Fritschi, 2001). Patients with neuropathy should also undergo evaluation of neuro-logic status using a monofilament device by an experienced ex-aminer (Fig. 41-11). Patients with pressure areas, such as calluses, or thick toenails should see the podiatrist routinely for treatment of calluses and trimming of nails.
Additional aspects of preventive foot care that are taught to the patient and family include the following:
· Properly bathing, drying, and lubricating the feet, taking care not to allow moisture (water or lotion) to accumulate between the toes
· Wearing closed-toe shoes that fit well. Podiatrists can pro-vide patients with inserts (orthotics) to remove pressure from pressure points on the foot. New shoes should be bro-ken in slowly (ie, worn for 1 to 2 hours initially, with grad-ual increases in the length of time worn) to avoid blister formation. Patients with bony deformities may need extra-wide shoes or extra-depth shoes. High-risk behaviors should be avoided, such as walking barefoot, using heating pads on the feet, wearing open-toed shoes, soaking the feet, and shaving calluses.
· Trimming toenails straight across and filing sharp corners to follow the contour of the toe (American Association of Diabetes Educators, 1998). If patients have visual deficits or thickened toenails, a podiatrist should cut the nails.
· Reducing risk factors, such as smoking and elevated blood lipids, that contribute to peripheral vascular disease
· Avoiding home remedies or over-the-counter agents or self-medicating to treat foot problems (Fritschi, 2001)
Blood glucose control is important for avoiding decreased re-sistance to infections and for preventing diabetic neuropathy. The patient may be referred by the physician to a wound care center for managing persistent wounds of the feet or legs. Many wound care centers provide diabetes education; however, the patient needs to discuss recommendations for treating wounds with his or her own physician, as well as raising any questions about diabetes management.