|
|
Lee J. Sanders, D.P.M.Danielle and Nicole, please change M.D. to D.P.M., and add my middle initial "J". Done, Nicole
08-27-2010
- In the Caribbean, among individuals with previous diabetic foot ulcer (DFU), 47% barefoot in the home, 17% barefoot outside the home.
- In Trinidad and Tobago, foot problems account for ~14% of hospital admissions, and 29% of bed occupancy by people with diabetes.
- There is a high rate of diabetes related lower-extremity amputations in the Caribbean black population.
- Sepsis and cardiac disease are the most common causes of death following lower extremity amputation (LEA).
- Foot trauma was a major cause of amputation in 51% of the diabetes-related LEA performed at 3 major hospitals in Trinidad (POSGH, SFGH and SGCH) in 2000-2004 (Solomon).
- A graphic illustration of a foreign body induced foot ulcer in a neuropathic diabetic was recently published in the New England Journal of Medicine by T&T physicians (Teelucksingh).
- The unrecognized loss of slippers from one's feet while walking (the "slipping slipper sign") is a marker for severe diabetic peripheral neuropathy and prevalent among those with active foot disease. (Teelucksingh).
- Foot ulcers should be treated with meticulous wound care, wound debridement, daily dressing changes, and off-loading of the foot.
- Infected wounds require culture directed antibiotics. Moderate-to-severe infections require early hospitalization with intravenous antibiotics and specialized surgical care. Neurologic and vascular status should be evaluated.
- Preventive diabetic foot care includes educating patients about the need for properly fitting shoes (and not going barefoot) to reduce the risk of lower limb complications, with referral to a podiatrist if needed.
- Multidisciplinary foot care teams are needed to reduce amputation rates. Minimal model: GP, nurse and podiatrist, Intermediate model: hospital setting, diabetologist, surgeon, nurse and podiatrist.
- Diabetic foot ulcer (DFU): A non-healing or poorly healing partial or full thickness wound below the ankle in an individual with diabetes, critical in the natural history of the diabetic foot.
- Most common sites: plantar surface of foot (metatarsal heads and midfoot), toes (dorsal interphalangeal joints or distal tip).
- Pathogenesis: DFUs frequently caused by repetitive injury to an insensate foot.
- Ill- fitting shoes are the most frequent cause of DFUs.
- Risk factors for DFUs: peripheral neuropathy, peripheral vascular disease, foot deformities (hammertoes, clawtoes, prominent metatarsal heads, bunion, rocker-bottom foot), vibratory perception threshold (VPT) 25V or greater, past foot ulcer, visual impairment, diabetic nephropathy (especially patients on dialysis), poor glycemic control and cigarette smoking.
- Incidence: annual population-based incidence in people with diabetes is from 1.9% to 2.2%.
- Prevalence range: from 1.8% in South Asians living in the U.K. to 11.8% in the United States.
- Lifetime risk for DFUs estimated to be as high as 25%.
- DFUs most common precursor of amputation; 85% of amputations are preceded by an active foot ulcer.
- Ulcer related costs per episode average $13,179 (range $1,892 to $27,721) and increase with severity level. Hospitalization is a major cost driver.
- Classified as neuropathic, ischemic or neuroischemic, based upon the presence or absence of ischemia in the common background of neuropathy. Several specific classifications exist and are listed below.
-
Wagner-Meggitt classification: foot ulcers are divided into six grades based on depth, presence or absence of infection and gangrene. All grades except 5 can be converted to a Grade 0 foot. Grade 0 - skin is intact; Grade 1 - superficial ulcer; Grade 2 - deep ulcer reaches tendon, bone or joint capsule; Grade 3 - deeper tissues involved with abscess, osteomyelitis or tendinitis with extension along midfoot compartments of tendon sheaths; Grade 4 - gangrene of toe, toes or forefoot, surgical ablation is indicated; Grade 5 - gangrene involves the whole foot, salvage not possible. Amputation below the knee.
-
University of Texas Classification: The UT system assesses ulcer depth, the presence of wound infection and signs of ischemia. Grades: grade 0 - intact skin (pre- or postulcerative site that has healed); grade 1 - superficial wound not involving tendon, capsule or bone; grade 2- wound penetrating to tendon or capsule; grade 3- wound penetrating bone or joint. Within each grade there are four stages: stage A - clean wound; stage B - nonischemic infected wounds; stage C- ischemic noninfected wounds; and stage D- ischemic infected wounds.
- The PEDIS system: Diabetic foot ulcer classification for research purposes. Evaluates five important clinical characteristics, Perfusion, Extent/size, Depth/tissue loss, Infection, and Sensation (International Working Group on the Diabetic Foot).
- Early signs of emerging DFU: mild erythema, elevated skin temperature, blister formation and serous or serosanguinous drainage on socks or bed linen.
- Neuropathic ulcers: usually surrounded by callus, located at the tips of the toes, on the tops of the interphalangeal joints and beneath the metatarsal heads, and painless unless infected.
- Neuroischemic ulcers: usually located on the margins of the foot, over boney prominences (1st and 5th metararsal heads). A halo of erythema often surrounds the ulcer. Often associated with pain secondary to ischemia or infection.
- Early detection of foot lesions and aggressive care can reduce risk for amputation.
- Requires detailed history and careful systematic inspection of the feet in a well-lit room.
- Must include neurologic, vascular, dermatologic, and musculoskeletal assessment.
- Inspect footwear to determine correct fit (length, width, and depth), condition (state of wear, protruding seams or nails) and suitability for the individual's foot structure and function.
- Shoes should serve to accommodate foot deformities and to protect the high-risk foot from injury.
- ADA Risk Classification: Risk categories 0-3, determined by the presence and combination of the following risk factors: peripheral neuropathy with loss of protectice sensation (LOPS); peripheral arterial disease (PAD), foot deformity, and history of foot ulcer or amputation.
- Treatment recommendations and follow-up are based upon the level of risk.
- Wound debridement with scalpel to remove callus and necrotic tissue can be done in primary care setting, but preferable to refer to diabetic foot specialist.
- Wound dressings to control exudate and maintain moist environment.
- Mechanical off-loading (cornerstone of treatment for plantar ulcers): total contact cast (TCC), Scotch cast boot or removable cast walker (RCW). Once DFU is healed, evaluate for custom molded insoles/orthotics and therapeutic footwear.
- Infection: Diabetic foot infections require attention to local (foot) and systemic (metabolic) issues and coordinated management by a multidisciplinary foot care team.
- Avoid prescribing antibiotics for uninfected ulcerations, wounds lacking purulence or any manifestations of inflammation.
- Determine the need for surgical and infectious disease consultation.
- Superficial ulcer with infection: debridement and oral antibiotics targeted at Staphylococcus aureus and streptococci. (see ABX Guide Diabetic Foot Infection)
- Infected wounds may require: incision and drainage, excision of infected necrotic tissues, local amputation, revascularization.
- Deep (limb threatening) infection: emergent surgical drainage, debridement of necrotic tissues, broad-spectrum intravenous antibiotics targeted at Gram-positive and Gram-negative organisms including anaerobes. (see ABX Guide Diabetic Foot Infection)
- Smoking cessation.
- Commonest combination of factors resulting in DFUs: peripheral neuropathy, foot deformity and trauma.
- The most predictive single risk factor for ulceration is a past history of ulceration or amputation.
- The habit of going barefoot is common in developing countries, increasing risk of DFUs.
- Patients must understand the implications of sensory loss, the importance of appropriate, properly fitted footwear and avoidance of barefoot walking.
- Footwear is a major modifiable risk factor.
- Shoes should be "foot shaped", with roomy toe box, snugly fitting heel cup, heels low (<5cm high), shoe lining smooth, sole sufficiently thick to prevent puncture wounds, shoe fastened with lace or strap to hold the foot back in the shoe, athletic shoes useful if sufficiently long, broad and deep. Wearing socks is advised to reduce friction. Custom made (bespoke) shoes can accommodate moderate-to-severe foot/ankle deformities and partial foot amputations. In hot climates, sandals should have closed toes. AVOID stiff leather dress shoes, high heels, thin soles, slip on style, and flip-flops (thongs).
|
|
