Ankle-brachial index

Background

Ankle-brachial index (ABI)

• How to measure:
  1. Position patient supine
  2. Measure SBP from both brachial arteries using cuff and handheld Doppler over the AC fossa
  3. Measure SBP from both DP and PT arteries using cuff placed just proximal to the malleoli with Doppler over artery (5-8% of normal patients have absent DP pulse)
  4. Calculate ABI on each leg by taking the highest ankle SBP (between DP and PT) on that leg divided by the highest brachial SBP and record to 2 decimal places

ABI	Meaning
<0.40	Severe occlusion
0.40–0.69	Moderate occlusion
0.70–0.90	Mild occlusion
0.91–1.30	Normal
>1.30	Poorly compressible/calcified vessels

See Also

• Acute arterial ischemia

References

Authors

Ross Donaldson, Michael O'Brien, MD, Michael Holtz