Dialysis Technician Practice Exam

What is one common method to remove solutes during dialysis?

1. Absorption

2. Convection

3. Diffusion

4. Filtration

The correct answer is: Convection

The correct method for removing solutes during dialysis is convection. Convection refers to the process where solutes are carried along with the movement of a solvent, primarily due to the differences in pressure. In the context of dialysis, convection occurs when fluid is moved across a semipermeable membrane, carrying solutes along with it due to the pressure gradient that is created during the dialysis process. In hemodialysis, this often happens when the dialysate flows at a certain rate, creating a 'bulk flow' that drags smaller solutes across the membrane into the dialysate solution. This is particularly effective for the removal of larger solutes that may not diffuse as easily. While absorption, diffusion, and filtration are also important concepts in dialysis, they operate on different principles. Absorption is more related to the uptake of substances rather than their removal. Diffusion relies on a concentration gradient where solutes move from an area of higher concentration to an area of lower concentration but does not take pressure into account like convection does. Filtration generally addresses the movement of water and solutes based on size or charge but does not necessarily include the dynamic flow aspect that convection provides. Thus, convection is central to effectively removing solutes from the blood during