(Vowden & Vowden, 2001)

An ankle brachial pressure index (ABPI) of 0.8 is seen by some as a definitive decision-making number, and it has almost become the ‘Holy Grail’ of leg ulcer assessment (Vowden & Vowden, 2001).

When interpreting ABPI in a person with a venous ulcer, a ratio of:

  • Less than 0.5 indicates severe arterial insufficiency and compression treatment is contraindicated. Refer urgently to a specialist vascular clinic for further assessment.
  • Between 0.5 and 0.8 suggests the presence of arterial disease or mixed arterial/venous disease. Compression should generally be avoided. However, reduced compression can be used under specialist advice and with strict supervision. Refer the person for specialist vascular assessment.
  • Greater than 0.8 indicates compression may be safely applied in most people. Any signs of arterial disease e.g. intermittent claudication, pain at rest etc. should be ruled out before considering applying compression. For people with cardiac failure, consider seeking specialist advice as there may be a risk of fluid overload if not closely monitored. A full patient and lower limb assessment will assist with clinical judgement.
  • Greater than 1.3 may suggest the presence of arterial calcification, such as in some people with diabetes, rheumatoid arthritis, systemic vasculitis, atherosclerotic disease, and advanced chronic renal failure.
  • For values above 1.5, the vessels are likely to be incompressible, and the result cannot be relied on to guide clinical decisions. Care must be taken in interpreting ABPI results in people with these conditions, as they may be misleadingly high. Compression therapy should be used with caution in people with diabetes, who may have unreliable ABPIs due to arterial calcification as well as an underlying sensory neuropathy. Refer to a vascular service as further assessments may be required to determine the person’s suitability for compression therapy.

(NICE 2019, revised 2024)

Patients with venous disease generally have warm, well-perfused feet with palpable foot pulses (Newton, 2010).

While ABPI is a significant element when undertaking a full holistic assessment, it is important to understand that it does not diagnose venous disease. ABPI will only assess for the presence of significant arterial disease and, therefore, assess the patient’s suitability for compression therapy (Wounds UK, 2019).

All patients presenting with a venous leg ulcer should be referred to either a specialist leg ulcer clinic or a vascular team (NICE, 2014, 2019; Wounds UK, 2013).