Ankle Brachial Pressure Index Lab

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

vascular doppler

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

30-45 degrees

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

superficial

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

flat

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

deep

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

dorsalis pedis, posterior tibial

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

P(leg)/P(arms)

Normal range for ABI

0.95-1.20

ABI <0.95 indicates

arterial disease

ABI < 0.6 contraindicates

compression bandages

ABI > 0.5 and < 0.95 is associated with

intermittent claudication

ABI < 0.5 indicates

severe arterial disease

ABI < 0.5 is associated with

pain at rest

ABI < 0.2 is associated with (2)

gangrene, ischemia

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

fall

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.

higher

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

missed

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.

high

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.

negative