Ankle–brachial pressure index Ankle–brachial pressure index The ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm (brachium). Compared to the arm, lower blood pressure in the leg suggests blocked arteries due to peripheral artery disease (PAD). The ABPI is calculated by dividing the systolic blood pressure at the ankle by the systolic blood pressure in the arm. The patient must be placed supine, without the head or any extremities dangling over the edge of the table. Measurement of ankle blood pressures in a seated position will
Brachial artery of the biceps, and, with the use of a stethoscope and sphygmomanometer (blood pressure cuff) often used to measure the blood pressure. The brachial artery is closely related to the median nerve; in proximal regions, the median nerve is immediately lateral to the brachial artery. Distally, the median nerve crosses the medial side of the brachial artery and lies anterior to the elbow joint. The brachial artery gives rise to the following branches: It also gives rise to important anastomotic networks of the elbow and (as the axillary artery) the shoulder. The biceps head is lateral to the brachial artery.