Ankle-Brachial Pressure Index (ABPI)

In addition to examination the most important objective indicator of lower limb ischaemia is the ABPI. In the upright position, the blood pressure at the ankle is slightly higher than the brachial (arm) blood pressure, testing with both arms. The ratio of ankle blood pressure to the brachial blood pressure is defined as ABPI and is normally greater than 1, the range of normal being 0.8 – 1.2.

• In good health, the ABPI is 1 or more,
• intermittent claudication is 0.5 - 0.95,
• rest pain is 0.3 – 0.5, and
• gangrene and ulceration less than 0.2

This is with the proviso that the arteries are not too rigid to test this way. If the ABPI is greater than 1.5, the chances are that the arteries are rigid. In this case, taking the toe pressure is more accurate, and this would also be a more accurate way of testing with diabetes.

Amended April 2008