What is the management plan for a diabetic patient with a foot ulcer?

Management of Diabetic Foot Ulcers

All diabetic patients with foot ulcers require immediate comprehensive assessment including vascular evaluation, infection screening, and pressure offloading, with the primary goal of preventing amputation and promoting healing through a structured, evidence-based approach. 1

Immediate Assessment and Risk Stratification

Vascular Assessment

• Evaluate every diabetic foot ulcer for peripheral artery disease (PAD) by measuring ankle systolic pressure, ankle-brachial index (ABI), and obtaining ankle or pedal Doppler arterial waveforms 1
• Use bedside non-invasive tests: ABI 0.9-1.3, toe-brachial index ≥0.75, or triphasic pedal Doppler waveforms largely exclude PAD 1
• Note that ABI can be falsely elevated in diabetic patients due to arterial calcification, making toe pressure or transcutaneous oxygen pressure (TcPO2) more reliable 2
• Measure skin perfusion pressure, toe pressure, or TcPO2 to assess healing potential: values of ≥40 mmHg, ≥30 mmHg, or ≥25 mmHg respectively increase healing probability by at least 25% 1

Infection Assessment

• Examine for signs of infection: erythema, warmth, tenderness, purulent discharge 3
• Classify infection severity as mild (superficial skin infection), moderate, or severe (deep tissue involvement, systemic signs) 3
• Obtain wound cultures before starting antibiotics to guide therapy 3
• Order complete blood count, C-reactive protein, and blood glucose levels 3
• Perform plain radiography to assess for osteomyelitis or foot deformities 3

Ulcer Characteristics

• Measure ulcer depth and extent to determine severity 1, 3
• Assess for exposed bone or joint involvement 3
• Evaluate for peripheral neuropathy using 10g monofilament test and/or 128 Hz tuning fork 3

Urgent Interventions

When to Consider Emergency Revascularization

Consider urgent vascular imaging and revascularization if any of the following are present:

• Toe pressure <30 mmHg or TcPO2 <25 mmHg 1
• Ankle pressure <50 mmHg or ABI <0.5 1
• Signs of PAD with foot infection (particularly high amputation risk) 1
• Ulcer not improving within 6 weeks despite optimal management, regardless of initial vascular test results 1

The aim of revascularization is to restore direct flow to at least one foot artery, preferably the artery supplying the wound region, achieving minimum skin perfusion pressure ≥40 mmHg, toe pressure ≥30 mmHg, or TcPO2 ≥25 mmHg 1

Infection Management

For mild infections (superficial skin involvement):

• Cleanse and debride all necrotic tissue and surrounding callus 1, 3
• Start empiric oral antibiotics targeting S. aureus and streptococci 1, 3
• Duration: 1-2 weeks for soft tissue infections 3

For moderate to severe infections (deep tissue, limb-threatening):

• Urgently evaluate for surgical intervention to remove necrotic tissue, including infected bone, and drain abscesses 1, 3
• Initiate empiric parenteral broad-spectrum antibiotics covering gram-positive, gram-negative, and anaerobic bacteria 1, 3
• Adjust antibiotic regimen based on culture results and clinical response 1, 3
• Duration: 2-4 weeks for moderate to severe infections; 6 weeks for osteomyelitis 3

Critical caveat: Do not use antibiotics for uninfected ulcers—antibiotics treat infection, not wounds, and inappropriate use promotes antimicrobial resistance 4

Core Treatment Principles

Pressure Offloading (Cornerstone of Treatment)

For neuropathic plantar ulcers:

• The preferred treatment is a non-removable knee-high offloading device: either total contact cast (TCC) or removable walker rendered irremovable 1, 3
• When non-removable devices are contraindicated, use removable offloading devices 1, 3
• When these devices are contraindicated, use footwear that best offloads the ulcer 1

For non-plantar ulcers (including ankle ulcers):

• Consider shoe modifications, temporary footwear, toe-spacers, or orthoses 1, 3
• If other forms of biomechanical relief are unavailable, consider felted foam combined with appropriate footwear 1

All patients:

• Instruct to limit standing and walking, use crutches if necessary 1, 3

Wound Care

Debridement:

• Perform sharp debridement of all necrotic tissue and surrounding callus, repeat as needed 1, 3
• This reduces bacterial colonization and facilitates healing 1

Dressings:

• Inspect the ulcer frequently 1, 3
• Select dressings to control excess exudation and maintain moist environment 1, 3
• Do not use honey, collagen, or alginate dressings for wound healing 1
• Do not use topical phenytoin or herbal remedy dressings 1
• Consider sucrose-octasulfate impregnated dressing as adjunctive treatment in non-infected neuro-ischemic ulcers that have insufficient healing after 2 weeks of best standard care including offloading 1

Avoid foot soaking as it causes skin maceration 3

Adjunctive Therapies (When Standard Care Fails)

Consider the following only after standard care has been optimized:

• Negative pressure wound therapy for post-operative wounds 1, 3
• Hyperbaric oxygen therapy as adjunct in neuro-ischemic or ischemic ulcers where standard care has failed and resources exist 1
• Topical oxygen therapy where standard care has failed and resources exist 1
• Autologous leucocyte, platelet, and fibrin patch where best standard care has been ineffective and resources/expertise exist for regular venepuncture 1
• Placental-derived products where standard care has failed 1

Do not routinely use:

• Cellular or acellular skin substitute products 1
• Growth factor therapy 1
• Physical therapies 1
• Other gases (cold atmospheric plasma, ozone, nitric oxide, CO2) 1

Metabolic and Cardiovascular Management

• Optimize blood glucose control 3
• Emphasize cardiovascular risk reduction: smoking cessation, control of hypertension and dyslipidemia, use of aspirin or clopidogrel 1

Prevention of Recurrence

Patient Education

• Educate patients at risk (IWGDF risk 1-3) to protect feet by not walking barefoot, not walking in socks without shoes, and not walking in thin-soled slippers indoors or outdoors 1
• Instruct to wash feet daily with careful drying between toes, use emollients for dry skin, and cut toenails straight across 1
• Educate to examine feet daily and rapidly contact healthcare professional with presence or suspicion of pre-ulcerative lesion 1
• Provide structured education about appropriate foot self-care 1

Therapeutic Footwear

• For patients with healed plantar foot ulcers (IWGDF risk 3), prescribe therapeutic footwear with demonstrated plantar pressure-relieving effect and encourage consistent wear both indoors and outdoors 1, 3
• For patients with foot deformity or pre-ulcerative lesions (IWGDF risk 2-3), consider extra-depth shoes, custom-made footwear, custom-made insoles, and/or toe orthoses 1

Follow-up Schedule Based on Risk

• IWGDF risk 1 (loss of protective sensation or PAD): Every 6-12 months 1, 3
• IWGDF risk 2 (deformity or pre-ulcerative lesions): Every 3-6 months 1, 3
• IWGDF risk 3 (history of foot ulceration or amputation): Every 1-3 months 1, 3

Common Pitfalls to Avoid

• Optimal wound care cannot compensate for continuing trauma to the wound bed, or inadequately treated ischemia or infection—address all three simultaneously 1
• Neglecting vascular assessment before aggressive debridement 3
• Relying solely on ABI for vascular assessment in diabetic patients due to arterial calcification 2
• Using antibiotics for uninfected wounds 4
• Failing to provide non-removable offloading devices for plantar neuropathic ulcers 1, 3
• Inadequate patient education about foot care and early warning signs 3
• If contemplating major (above ankle) amputation, first consider revascularization 1

Multidisciplinary Approach

Treatment should involve a multidisciplinary team with rapid access to facilities for diagnosing and treating PAD; both endovascular techniques and bypass surgery should be available 1