The bruit in an AV fistula or graft is detected by

• A. Palpating for thrill
• B. Listening with a stethoscope
• C. Measuring blood pressure over the fistula
• D. Ultrasound velocity measurement

Answer: (B)

Bruit is the audible sound created by turbulent blood flow through the AV access, and it is detected by listening with a stethoscope over the fistula or graft. This sound indicates that blood is moving through the access and that it is patent. A separate sign, a thrill, is a palpable vibration felt over the site and also suggests patency, but it’s felt, not heard. Measuring blood pressure over the fistula isn’t used to assess bruit and can be harmful to the access. Ultrasound velocity measurement can quantify flow, but it requires equipment and isn’t the bedside method used to detect the audible bruit.