Extremity blood pressures are taken in the arms, legs, fingers, and toes.
This diagnostic tool provides important information about blood flow in the arteries, and it is safe, noninvasive, and relatively inexpensive.
Extremity blood pressures help diagnose the existence of an arterial blockage, its location, and its severity.
When a person has atherosclerosis, arteries become narrowed, blocked or partially blocked by plaque build-up. Measuring blood pressures in the extremities (arms and legs) can give important information about the existence of a blockage, its location, and its severity.
There are three types of extremity blood pressure tests.
Ankle-brachial index (ABI);
Toe systolic pressure index (TSPI); and
Segmental blood pressures.
To prepare for a blood pressure reading, patients should rest quietly for 5 minutes and remove clothing from the limb to be tested.
There are no risks for extremity blood pressure testing.
WHAT TO EXPECT
Extremity blood pressures are measured in a similar manner to the arm blood pressures. An inflatable cuff with a pressure gauge, called a sphygmomanometer, is used along with a listening device to monitor blood flow and pulse. The inflatable cuff is wrapped around the extremity, usually the leg, and a highly sensitive device called a Doppler ultrasound transducer uses sound waves to detect the rate of blood flow through the artery. The cuff is inflated until blood flow (and pulse) below the cuff is cut off. As the cuff is slowly deflated, blood flow and pulse below the cuff return. When this happens, the pressure reading is recorded. Unlike the routine arm blood pressures where diastolic and systolic pressure are measured, extremity blood pressures measure only systolic pressure.