What diagnostic tests are recommended for a patient presenting with cold extremities and poor wound healing?

From the Guidelines

Patients presenting with cold extremities and poor wound healing should undergo diagnostic tests including Ankle-Brachial Index (ABI), toe pressure/toe-brachial index (TBI), transcutaneous oxygen pressure (TcPO2), and skin perfusion pressure (SPP) to assess arterial perfusion and establish the diagnosis of Peripheral Artery Disease (PAD) or Chronic Limb-Threatening Ischemia (CLTI).

Diagnostic Tests

• ABI: a simple, noninvasive test that measures systolic blood pressures at the arms and ankles to establish the diagnosis of PAD 1
• TBI: used to establish the diagnosis of PAD in the setting of non-compressible arteries (ABI >1.40) and to assess perfusion in patients with suspected CLTI 1
• TcPO2: measures the oxygen pressure in the skin to assess perfusion and predict wound healing 1
• SPP: measures the skin perfusion pressure to assess perfusion and predict wound healing 1

Interpretation of Results

• ABI ≤0.90: abnormal, indicative of PAD 1
• TBI <0.70: abnormal, indicative of PAD 1
• TcPO2 <30 mmHg: indicative of severe ischemia and poor wound healing potential 1
• SPP <40 mmHg: indicative of poor wound healing potential 1

Clinical Decision-Making

• Urgent vascular imaging and revascularization: should be considered in patients with a diabetic foot ulcer and an ankle pressure <50 mmHg, toe pressure <30 mmHg, or a TcPO2 <25 mmHg 1
• Referral to specialized care centers: should be considered for patients with chronic, previously treated, or severe infections, or those at risk for infection with antibiotic-resistant organisms 1

From the Research

Diagnostic Tests for Cold Extremities and Poor Wound Healing

The following diagnostic tests are recommended for a patient presenting with cold extremities and poor wound healing:

• Vascular assessment, including macrovascular and microvascular investigation, to evaluate blood flow and identify potential circulatory issues 2
• Laboratory tests, such as C-reactive protein, procalcitonin, presepsin, and bacterial protease activity, to detect infection and inflammation 3
• Imaging modalities, including plain radiography, computed tomography, magnetic resonance imaging, ultrasound imaging, spatial frequency domain imaging, thermography, autofluorescence imaging, and biosensors, to visualize and quantify wound infection 3
• Point-of-care diagnostic tests, such as elevated neutrophil derived protease activity (EPA) and bacterial protease activity (BPA), to detect chronic inflammation and bacterial pathogenesis in chronic wounds 4
• Fluorescence microangiography to quantify microvascular dysfunction in connection with non-healing chronic wounds 2

Recommended Diagnostic Approach

The recommended diagnostic approach involves:

• Testing for bacterial protease activity (BPA) first to identify the presence of pathogenic bacteria 4
• If BPA test is negative, testing for elevated neutrophil derived protease activity (EPA) to detect chronic inflammation 4
• Using imaging modalities and laboratory tests to support diagnosis and guide treatment 3, 2
• Considering the patient's circulation status and tailoring treatment to target changes in vascular endothelial growth factor receptors (VEGFRs) 5