If there is an absent thrill during a fistula site assessment, what action should the technician take?

The correct action in the scenario of an absent thrill during a fistula site assessment is to refrain from cannulating the access due to the potential for clotting. The thrill is a palpable vibration felt over the fistula that indicates adequate blood flow and function. Its absence raises concerns that the fistula may be compromised, which can include issues such as thrombosis or stenosis. Cannulating a site that lacks a thrill can exacerbate underlying problems, potentially leading to further complications.

In situations where the thrill is absent, assessing the integrity of the fistula's blood flow is crucial. Moving forward with cannulation without addressing the lack of thrill could risk damaging the access or causing inadequate dialysis. Therefore, prioritizing the health of the vascular access by choosing not to cannulate reflects best practices for patient care and safety in hemodialysis.