Which sign indicates patency of an arteriovenous fistula used for hemodialysis?

• A. Absence of thrill
• B. Pain at the site
• C. Palpable thrill and audible bruit
• D. Redness around the access

Answer: (C)

Patency of an arteriovenous fistula is indicated by a palpable thrill and an audible bruit over the access. The thrill is a vibration felt when you place your fingers gently over the fistula, reflecting turbulent blood flow as blood moves from artery to vein. The bruit is the swooshing sound heard with a stethoscope, produced by that same flow. Together, they signal that the fistula is open and functioning for dialysis. If either thrill or bruit is absent or weakened, flow may be compromised due to narrowing or clotting, signaling potential access failure. Pain at the site or redness around the access can point to infection, irritation, or other complications rather than patency.