To determine the patency of an arteriovenous vascular access, the dialysis technician should initially feel for the presence of

• A. A thrill
• B. A bruit
• C. A pulse at the access
• D. Color change in skin

Answer: (A)

Feeling for a thrill is the first check because the palpable vibration over the access directly shows high-velocity blood flow through the fistula or graft, indicating patency. If the thrill is present, flow is ongoing; if it’s absent or diminished, there may be narrowing or blockage requiring further evaluation (like Doppler ultrasound). A bruit can be heard with a stethoscope and supports that flow is present, but it’s secondary to the initial palpation for the thrill. A pulse at the access is not a reliable indicator of patency, and color changes in the skin aren’t specific enough to assess the access itself.