How to manage a patient in their 60s with a 25-year history of type 2 (T2DM) diabetes who has a rapidly spreading superficial ulcer on their ankle, poor blood flow in the dorsal pedis and posterior tibial artery, and no palpable pulse?

Management of Diabetic Foot Ulcer with Critical Limb Ischemia

This patient requires urgent vascular imaging within 24-48 hours and immediate referral to a multidisciplinary diabetic foot service for consideration of revascularization, as the absent pulses and poor arterial flow indicate critical limb ischemia that will prevent ulcer healing and lead to amputation without intervention. 1, 2

Immediate Vascular Assessment (Within 24-48 Hours)

Obtain bedside perfusion measurements immediately:

• Measure toe-brachial index (TBI), as ankle-brachial index (ABI) is unreliable in diabetics due to medial artery calcification 1, 2
• A TBI <0.7 indicates significant peripheral artery disease requiring revascularization consideration 1
• Measure toe pressure and transcutaneous oxygen pressure (TcPO2) 2
• Critical thresholds requiring urgent revascularization: toe pressure <30 mmHg, ankle pressure <50 mmHg, or TcPO2 <25 mmHg 1, 2

This patient meets criteria for "complicated DFU" and requires referral to specialized diabetic foot service within 48-72 hours given the rapidly spreading ulcer with severe ischemia. 1

Vascular Imaging and Revascularization Planning

Proceed immediately to anatomical vascular imaging since bedside testing confirms severe ischemia:

• Use duplex ultrasound, CT angiography, or MR angiography to visualize the entire lower extremity arterial tree from aorta to foot 1
• Critical requirement: detailed visualization of below-the-knee and pedal arteries in anteroposterior and lateral planes 1
• Digital subtraction angiography should only be performed when revascularization is planned 1

Revascularization goals:

• Restore direct blood flow to at least one foot artery, preferably the artery supplying the ulcer region 1, 2
• Target minimum toe pressure ≥30 mmHg or TcPO2 ≥25 mmHg post-procedure 1, 2
• Both percutaneous transluminal angioplasty and surgical bypass (preferably with saphenous vein) should be considered based on anatomy 1

Wound Management During Vascular Workup

Perform sharp surgical debridement immediately:

• Remove all necrotic tissue and slough from the wound base 2
• Repeat debridement as needed during the treatment course 2
• Critical pitfall to avoid: Do NOT rely on superficial wound swabs for culture; obtain deep tissue or bone samples if infection is suspected 1

Implement strict pressure offloading:

• Use total contact casting or specialized offloading footwear to completely relieve pressure from the ulcerated area 1, 2
• This is non-negotiable even during the vascular workup period 1

Infection Assessment and Management

Evaluate for superimposed infection immediately:

• Look for erythema >2 cm around the ulcer, purulent discharge, warmth, edema, or systemic signs (fever, elevated WBC, elevated CRP) 1
• If infection is present, obtain deep tissue culture via curettage or surgical sampling—not superficial swab 1
• Start empiric broad-spectrum IV antibiotics if severe infection is present, then narrow based on culture results 1
• If pus is present, surgical drainage must be performed urgently ("don't let the sun set on pus") 1

Glycemic and Cardiovascular Risk Management

Optimize diabetes control aggressively:

• Target HbA1c <7% through intensification of therapy 3
• This patient's 25-year diabetes history places them at extremely high risk for complications 4, 3

Implement comprehensive cardiovascular risk reduction:

• Mandatory smoking cessation support (critical given the vascular disease) 1, 2
• Initiate or optimize statin therapy 2
• Start antiplatelet therapy (aspirin or clopidogrel) 2
• Control blood pressure aggressively 2

Monitoring and Escalation Criteria

If revascularization is deemed not feasible or must be delayed:

• Consider IV prostacyclin (Iloprost) for 2-4 weeks, which improves limb salvage rates from 45% to 65% at 6 months in critical limb ischemia 1

Reassess perfusion if ulcer shows no improvement after 4 weeks of appropriate therapy to determine if revascularization assessment needs to be repeated 1

Hospitalization is required if:

• The ulcer becomes unstable (worsening size, depth, or signs of infection/ischemia) 1
• Systemic infection develops 1
• Urgent surgical debridement or revascularization is needed 1

Without revascularization in this patient with absent pulses and poor arterial flow, the ulcer will not heal and major amputation is highly likely. 1 The combination of absent pulses, poor radiologic flow, and a rapidly spreading ulcer represents critical limb ischemia requiring urgent multidisciplinary intervention. 1, 2