Ankle-brachial index
Background
Ankle-brachial index (ABI)
How to measure:
- Position patient supine
- Measure SBP from both brachial arteries using cuff and handheld Doppler over the AC fossa
- 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)
- 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 |