Which observation would most readily indicate patency of an arteriovenous fistula in a dialysis patient?

• A. Palpation of a thrill
• B. Auscultation of a thrill
• C. Absence of bruit
• D. Pain on palpation

Answer: (A)

Patency of an arteriovenous fistula is most readily indicated by a palpable thrill. The thrill is a noticeable vibration felt over the fistula when arterial blood rapidly shunts into the vein, signifying ongoing, unobstructed flow. This bedside cue is quick to detect by touch and doesn’t require equipment, making it the easiest way to confirm that the fistula is functioning. A bruit heard with a stethoscope can also indicate flow, but a thrill is more immediately evident at the bedside. Conversely, absence of a bruit would suggest reduced or absent flow, not patency, and pain on palpation isn’t a sign of a patent fistula and could signal other issues.