Ankle Brachial Pressure Index Lab

vascular doppler

sense frequency differences in blood flow; increasing frequency change whether the blood is flowing toward or away from the probe; higher pitch = greater blood flow velocity

30-45 degrees

When measuring brachial systolic BP with an 8 MHz doppler, the probe should be at what angle?

superficial

8 MHz dopplers are used for more SUPERFICIAL/DEEP peripheral vessels.

flat

When measuring brachial systolic BP with an 5 MHz doppler, the probe surface should be held?

deep

5 MHz dopplers are used for more SUPERFICIAL/DEEP peripheral vessels.

dorsalis pedis, posterior tibial

What two blood vessels can be used to measure ankle systolic pressure?

P(leg)/P(arms)

What is the formula to calculate the ABI for each leg?

0.95-1.20

Normal range for ABI

arterial disease

ABI <0.95 indicates

compression bandages

ABI < 0.6 contraindicates

intermittent claudication

ABI > 0.5 and < 0.95 is associated with

severe arterial disease

ABI < 0.5 indicates

pain at rest

ABI < 0.5 is associated with

gangrene, ischemia

ABI < 0.2 is associated with (2)

fall

If the cuff is repeatedly inflated or inflated for long periods of time, this can cause ankle pressure to RISE/FALL.

higher

If the cuff is placed too far superior to the ankle, ankle systolic pressure is not measured and the pressure recorded is usually LOWER/HIGHER than the correct pressure.

missed

The pulse is irregular or the cuff is deflated too rapidly can cause true systolic BP to be?

high

If vessels are calcified, the legs are large/fatty/edematous, the cuff size is too small, or the legs are dependent, BP can be falsely LOW/HIGH.

negative

If central systolic pressure is increased resulting in a higher baseline value, then the same amount of absolute pressure differences will result in a smaller difference in the ABI ratio, resulting in a potentially false POSITIVE/NEGATIVE.