How to treat a diabetic foot ulcer with necrotic slough on the right lateral side of the heel, accompanied by severe peripheral arterial disease (PAD) and occasional burning sensation?

Treatment of Diabetic Foot Ulcer with Severe PAD and Necrotic Slough

This patient requires urgent vascular imaging and revascularization given the severe peripheral arterial disease, combined with aggressive wound debridement, infection control if present, and pressure offloading as part of a comprehensive multidisciplinary approach. 1

Immediate Vascular Assessment and Intervention

The presence of severe PAD with a diabetic foot ulcer mandates urgent action to prevent limb loss:

• Obtain bedside perfusion measurements immediately: Measure toe pressure, ankle-brachial index (ABI), and if available, transcutaneous oxygen pressure (TcPO2) or skin perfusion pressure 1

• Proceed to urgent vascular imaging if: toe pressure <30 mmHg, TcPO2 <25 mmHg, ankle pressure <50 mmHg, or ABI <0.5 1

• Even without these specific measurements, given the stated "severe PAD," this patient likely meets criteria for urgent revascularization consideration 1

The goal of revascularization is to restore direct blood flow to at least one foot artery, preferably the artery supplying the lateral heel region where the ulcer is located, achieving minimum toe pressure ≥30 mmHg or TcPO2 ≥25 mmHg 1

Revascularization Technique Selection

Both endovascular and bypass surgery options should be available, with the choice based on: 1

• Morphological distribution of the arterial disease
• Patient comorbidities
• Availability of autogenous vein for bypass
• Local vascular expertise

Critical caveat: If infection is present alongside PAD, this patient is at particularly high risk for major amputation and requires emergency treatment with both vascular intervention and infection control 1

Wound Management

Aggressive Debridement

• Perform sharp surgical debridement of all necrotic slough at the wound base immediately and repeat as needed 1
• Remove all surrounding callus tissue 1
• Inspect the ulcer frequently for progression 1

The necrotic tissue must be removed to allow healing and prevent infection progression, though this should be coordinated with vascular status assessment 1

Infection Assessment and Treatment

Assess for signs of infection given the necrotic slough:

If superficial infection only (mild): 1

• Cleanse and debride thoroughly
• Start empiric oral antibiotics targeting S. aureus and streptococci

If deep infection (moderate to severe): 1

• Urgently evaluate for surgical intervention to remove necrotic tissue and drain any abscesses
• Initiate empiric parenteral broad-spectrum antibiotics covering gram-positive, gram-negative, and anaerobic bacteria
• Coordinate urgent vascular intervention simultaneously
• Adjust antibiotics based on culture results and clinical response

Local Wound Care

• Select dressings that control exudate while maintaining a moist wound environment 1
• Consider negative-pressure wound therapy for post-debridement wound management 1
• Avoid silver-containing or antimicrobial dressings as routine management (not well-supported) 1
• Do not use footbaths - these cause skin maceration 1

Pressure Offloading

For this lateral heel ulcer:

• Implement offloading with shoe modifications or temporary footwear designed to relieve pressure from the lateral heel 1
• Consider toe-spacers or orthoses if applicable 1
• If specialized devices unavailable, use felted foam with appropriate footwear 1
• Instruct the patient to strictly limit standing and walking; provide crutches 1

Note: Total contact casts are typically for plantar ulcers; this lateral heel location requires different offloading strategies 1

Cardiovascular Risk Management

All patients with ischemic diabetic foot ulcers require aggressive cardiovascular risk reduction: 1

• Smoking cessation support (critical)
• Blood pressure control
• Statin therapy
• Low-dose aspirin or clopidogrel

Monitoring and Follow-up

• If the ulcer does not improve within 6 weeks despite optimal management, proceed to vascular imaging and revascularization even if initial bedside tests were borderline 1

• After any revascularization procedure, continue comprehensive multidisciplinary care including ongoing wound management, offloading, and infection surveillance 1

Addressing the Burning Sensation

The occasional burning sensation likely represents neuropathic pain from diabetic neuropathy, but in the context of severe PAD, could also indicate critical ischemia or infection. This symptom reinforces the urgency of vascular assessment and does not change the primary treatment algorithm outlined above.

Common pitfall: Do not attribute poor healing to "diabetic microangiopathy" - this should not be considered the cause of non-healing in diabetic foot ulcers 1. The macrovascular PAD is the primary perfusion problem requiring intervention.