Doppler Segmental Pressures (UE) Flashcards
Limitations of Doppler Segmental Pressures (LE)?
- Cannot discriminate between stenosis and occlusion, localize area of obstruction, nor discriminate between CFA and external iliac disease.
- Calcified vessels render falsely elevated doppler pressures.
3.Uncompensated CHF may result in decreased ABI.
Artifactually elevated high thigh pressures when narrowing cuff used on thigh.
4.Difficult to interpret in presence of multi-level disease.
Patient positioning for Doppler Segmental Pressures (UE)?
Supine with arms relaxed at the patiens sides
What artery is used to obtain upper arm BP?
Brachial Artery
What arteries are used to obtain the forearm pressure?
Radial and Ulnar
What size cuffs are used and where are it placed?
12 x 20 cm cuff on upper arm
10 x 40 cm cuff on forearm bilaterally
What is the allen test used for?
to evaluate patency of the palmar arch
What are the techniques used for Doppler Segmental Pressures (UE)?
- with manual compression of radial artery by the technologist, patient clenches ipsilateral fist (<1) inducing pallor, while at the same time increases resistance
- With manual compression of the radial artery continuing, patient is asked to relax the hand
How does a normal allen test appear?
Reappearance of the normal color to indicate the ulnar artery is providing flow to the palmar arch
How does an abnormal allen test appear?
Color does not reappear to indicate: an ulnar artery occlusion or palmar arch obstruction
What does a 15-20 mm Hg difference from one brachial pressure to the other suggest?
a >50% stenosis of the subclavian and/or the vessel under the cuff
A > 15-20 mmHg drop from upper arm to forearm suggests:
- a brachial artery obstruction distal to the upper cuff
- obstruction in both radial and ulnar arteries
- obstruction in single forearm artery which has decreased pressure
A difference in > 20mm Hg between radial and ulnar pressures suggests:
obstruction in vessel with lower P