General

Synonym/Acronym:
Doppler, arterial ultrasound, duplex scan.

Rationale
To visualize and assess blood flow through the arteries of the upper and lower extremities toward diagnosing disorders such as occlusion and aneurysm and to evaluate for the presence of plaque and stenosis. This procedure can also be used to assess the effectiveness of therapeutic interventions such as arterial graphs and blood flow to transplanted organs.

Patient Preparation
There are no food or medication restrictions unless by medical direction. Some protocols may require the patient to restrict nicotine and caffeine for 1 to 2 hr before the procedure in order to avoid vasoconstriction or vasodilation.

Normal Findings

• Normal blood flow through the lower extremity arteries with no evidence of vessel occlusion or narrowing
• Normal arterial systolic and diastolic Doppler signals
• Normal reduction in systolic blood pressure (i.e., less than 20 mm Hg) when compared to a normal extremity
• Normal ankle-brachial index (ABI; greater than 0.85).

Critical Findings and Potential Interventions
N/A