Treating diabetic foot ulcers​

Diabetic foot ulcer is a common and serious complication of both type 1 and type 2 diabetes mellitus1. Diabetes is associated with ischaemia, neuropathy, peripheral artery disease, and foot deformities that lead to a particularly high risk of developing foot ulcers and a low likelihood of ulcer healing. Because of the reduced blood supply to the lower limb, diabetic foot ulcers face risk of necrosis, infection, and involvement of deep tissues, including bone2. Approaches to the management of diabetic foot ulcer include debridement, protection from trauma, treatment of infection, control of exudate, and promotion of healing3. Epidemiology Patients with type 1 or type 2 diabetes mellitus have a lifetime risk of a foot ulcer of up to 25%2 4. Infected or ischaemic diabetic foot ulcers account for approximately 25% of all hospital admissions for patients with diabetes3 4. Diabetic foot ulcers account for almost two-thirds of all non-traumatic lower limb amputations performed in the Europe and the US1 3 5.  The age-adjusted rate of lower-limb amputation is estimated to be 15 times greater in individuals with diabetes than in the general population1 2 4. These findings show how important it is to manage diabetic foot ulcer appropriately, quickly, and effectively. Aetiology The causes of diabetic foot ulceration are a combination of chronic narrowing of small arterioles that supply oxygen to the tissues, diabetic arteriolosclerosis, which results in tissue ischaemia, and high venous pressure, resulting in tissue oedema and hypoxia2. Patients with diabetes develop specific risk factors that lead to foot ulcers, including loss of sensation due to diabetic neuropathy, prior skin damage or ulcers, foot deformity or other causes of pressure, external trauma, infection, and chronic ischaemia due to peripheral artery disease1 2. Clinical and economic burden Globally, an estimated 422 million adults were living with diabetes in 2014, compared with 108 million in 19801. The global prevalence (age-standardised) of diabetes has nearly doubled since 1980, rising from 4.7% to 8.5% in the adult population, which reflects an increase in associated risk factors, mainly due to obesity1.  Rates of lower limb amputation, due to diabetic foot ulcer, are typically ten to 20 times those of non-diabetic populations7. In the US, in 2010, approximately 73,000 non-traumatic lower-limb amputations were performed in adults aged 20 years or older with diabetes; 60% occurred in people with diabetes7. In the US, Medicare claims data showed that between 2006 and 2008, patients with a diabetic foot ulcer were seen by their outpatient healthcare provider about 14 times per year and were hospitalised about 1.5 times per year. The US claims data also showed that the cost of care for each claimant with a diabetic foot ulcer was about USD 33,000 for all Medicare services per year8. Patients with a lower extremity amputation were seen by their outpatient healthcare provider about 12 times per year and were hospitalised about twice per year, with the total cost of care of USD 52,000 per year8. Effects on patient quality of life Studies have shown that people with diabetes who have a healed foot ulcer have a greater health-related quality of life (HRQoL) when compared with people with chronic, non-healed diabetic foot ulcers when evaluated using standard questionnaires9. Also, for caregivers of diabetic people with chronic, non-healing foot ulcers, there is a large emotional burden9. Risk of infection Chronic non-healing ulcers of the foot are susceptible to infection, which can lead to serious complications, including osteomyelitis and septicaemia10 11.  When a diagnosis of ulcer infection is made, treatment is based on the clinical stage of infection, and X-ray imaging is usually performed to exclude or confirm osteomyelitis11. The most common infecting organisms include aerobic Gram-positive cocci, aerobic gram-negative bacilli, and anaerobic organisms in deep ulcers10 11 12. According to the Infectious Disease Society of America (IDSA) guidelines, infection is present if there is obvious purulent drainage and/or the presence of two or more signs of inflammation (erythema, pain, tenderness, warmth, or induration)11. The management and treatment of infection of a diabetic foot ulcer should include a multidisciplinary team of experts including surgeons, infectious disease specialists, diabetologists, microbiologists and nursing staff11. [Text & Image section] Podcast   Prevention and risk management Taking preventive measures and understanding the risks associated with diabetic foot ulcers are important factors in reducing incidence of serious consequences. Early diagnosis and treatment also contribute to managing the risk of developing. In addition, educating and involving patients in their own foot care is an important and empowering aspect of managing risk and achieving better outcomes. Listen to Professor Paul Chadwick’s thoughts on patient empowerment in the podcast above. Download the guide below to provide your diabetic patient with resources to help them learn more about caring for their feet. [Download] Guide

Diagnosis, treatment and management of DFUs Successful diagnosis and treatment of diabetic foot ulcers involves a holistic approach that includes the patient’s physical, psychological, and social health and the status of the wound1. The management of diabetic foot ulcer begins with assessment, grading, and classifying the ulcer based on clinical evaluation of the extent and depth of the ulcer and the presence of infection, which determines the nature and intensity of treatment2 3 . The degree of ischaemia for patients with diabetic foot ulcers is assessed by ankle-brachial index (ABI) and toe pressure measurements3 . To test the peripheral neuropathy there are two simple and effective tests used: 10 g Monofilament for testing the sensory neuropathy should be applied at various sites along the plantar aspect of the foot. Tuning fork standard 128Hz is used to test the ability to feel vibrations; a biothesiometer is a device that also assesses the perception of vibration1  In patients with peripheral neuropathy, it is important to offload at-risk areas of the foot in order to redistribute pressures evenly4. Inadequate offloading leads to tissue damage and ulceration. To ensure holistic assessment and treatment of diabetic foot ulcers, the wound should be classified according to a validated clinical tool. The University of Texas (UT) system was the first diabetic foot ulcer classification to be validated and consists of three grades of ulcer and four . Holistic patient assessment and M.O.I.S.T. framework The management of hard-to-heal wounds relies on performing a holistic assessment of the person with a wound, using a framework that helps deliver optimal wound treatment. M.O.I.S.T. is such a framework, which encourages a systematic approach. It provides healthcare professionals guidance for planning and education with regard to local therapy6. The acronym M.O.I.S.T. represents: Moisture Balance Oxygen Balance Infection Control Support Tissue Learn more about M.O.I.S.T. at Clinical Learning Hub or take a more playful approach to learning about M.O.I.S.T. in Microworld.  Debridement and inspection The European Wound Management Association (EWMA) states that the emphasis in wound care for diabetic foot ulcers should be on radical and repeated debridement, bacterial control and frequent inspection and careful moisture balance to prevent maceration7. The patient’s vascular status must always be determined prior to sharp debridement. Patients needing revascularisation should not undergo extensive sharp debridement because of the risk of trauma to vascularly compromised tissues1. While it may seem logical that effective glucose control could promote healing of diabetic foot ulcers, there is no evidence in the published literature to support this assumption8. An explanation for this finding may be that small vessel diabetic arteriolosclerosis is irreversible and after a certain time is not responsive to normoglycaemia8. The role of dressings in the management of diabetic foot ulcers Following debridement, the diabetic foot ulcer should be kept clean and moist but free of excess exudate, with wound dressings selected based on the ulcer’s characteristics, such as the extent of exudate or necrotic tissue9.  Some dressings are also impregnated with antimicrobial agents to prevent infection and enhance ulcer healing10. Should infection occur, infection management is critical for promoting continued healing, including antibiotic treatment and the use of diagnostic tools like X-rays to rule out osteomyelitis. By using a dressing that creates a moist wound healing environment, a natural process to soften and remove devitalised tissue will occur. This process is called autolytic debridement. Care must be taken not to use a moisture-donating dressing, as this can predispose the skin to maceration. In addition, the application of moisture-retentive dressings in the presence of ischaemia and/or dry gangrene is not recommended11 12. It is important to incorporate strategies to prevent trauma and minimise wound-related pain during dressing changes13. This may include the use of soft silicone dressings and avoiding unnecessary manipulation of the wound14. It is now acknowledged that many patients, even those with neuropathy or neuroischaemia, can feel pain due to their wound or a procedure14. Other advanced treatments for diabetic foot ulcers Adjunctive therapies may improve ulcer healing, such as negative pressure wound therapy (NPWT), the use of custom-fit semipermeable polymeric membrane dressings, cultured human dermal grafts, and application of growth factors15. All ulcers subjected to sustained or frequent pressure and stress, including pressure-related heel ulcers or medial and lateral foot ulcers or repetitive moderate pressure (plantar foot ulcers) benefit from pressure reduction, which is accomplished with mechanical offloading. Offloading devices include total contact casts, cast walkers, shoe modifications, and other devices to assist in mobility15. Patient education for foot and DFU self-care Effective foot care should be a partnership between patients, carers and healthcare professionals. Educating patients about proper foot care and periodic foot examinations are effective interventions to prevent ulceration16.