How should I assess the severity of arterial insufficiency in a patient with an arterial ulcer?

To assess the severity of arterial insufficiency in a patient presenting with an arterial ulcer, the primary method is to measure the Ankle Brachial Pressure Index (ABPI) ¹,²,⁴.

• Clinical Assessment: Begin by asking about the presence and severity of possible symptoms of intermittent claudication and critical limb ischaemia ⁴. Examine the legs and feet for evidence of critical limb ischaemia, such as ulceration, and palpate the femoral, popliteal, and foot pulses ⁴. However, be aware that the absence of foot pulses may indicate arterial insufficiency, but palpation alone is not sufficient to rule it out ¹,².
• ABPI Measurement: The ABPI is the ratio of the ankle systolic blood pressure to the brachial systolic blood pressure ¹,². The patient should be resting and supine if possible ⁴. Record systolic blood pressure with an appropriately sized cuff in both arms and in the posterior tibial, dorsalis pedis, and, where possible, peroneal arteries ⁴. Measurements should be taken manually using a Doppler probe of suitable frequency in preference to an automated system ⁴. Document the nature of the Doppler ultrasound signals in the foot arteries ⁴. Calculate the index in each leg by dividing the highest ankle pressure by the highest arm pressure ⁴.
• Interpretation of ABPI Values:
  • Less than 0.5: Severe arterial insufficiency is likely, and compression stockings are contraindicated ¹,². The person should be referred urgently for specialist vascular assessment ¹,².
  • Greater than 0.5 to less than 0.8: Arterial disease or mixed arterial/venous disease is likely ¹,². Compression should generally be avoided, but reduced compression can be used under specialist advice and with strict supervision ¹,². The person should be referred for specialist vascular assessment ¹,².
  • Between 0.8 and 1.3: Arterial disease is unlikely, and compression stockings are generally safe to wear ¹,².
  • Greater than 1.3: High ABPI values may be due to arterial calcification, common in conditions such as diabetes, rheumatoid arthritis, systemic vasculitis, atherosclerotic disease, and advanced chronic renal failure ¹,². For values above 1.5, the vessels are likely to be incompressible, and the result cannot be relied on to guide clinical decisions ¹,². The person should be referred for specialist vascular assessment ¹,².
• Considerations for Patients with Diabetes: Do not exclude a diagnosis of peripheral arterial disease in people with diabetes based on a normal or raised ABPI alone ⁴. Pulse oximetry should not be used for diagnosing peripheral arterial disease in people with diabetes ⁴.
• Referral: People with chronic limb-threatening ischaemia should be referred urgently to a vascular multidisciplinary team ³. All people with peripheral arterial disease should be provided with information about their condition, tailored to their individual needs, to facilitate shared decision-making and help prevent disease progression ³,⁴.