How can a technician determine blood flow in a looped arteriovenous graft?

The ability to determine blood flow in a looped arteriovenous graft is crucial for assessing its functionality and ensuring effective dialysis. By occluding the blood flow at midpoint and feeling for a thrill or listening for a bruit, the technician is performing a physical examination that directly assesses blood movement within the graft.

In this context, the thrill refers to a vibration felt when blood is flowing through the graft, and a bruit is the sound heard through a stethoscope as blood moves. If there is a thrill or bruit present after occlusion, it indicates that blood is still flowing from the arterial side. Therefore, the presence of these indicators helps to identify the arterial segment of the graft post-occlusion.

This technique effectively differentiates the arterial side from the venous side, providing valuable information about the graft's blood flow dynamics. It is essential for the technician to accurately assess the functioning of the graft, which directly impacts the quality of care for the patient receiving dialysis.