Decreasing the patient7s prescribed blood flow rate affects the rate of which process during hemodialysis?

Decreasing the patient7s prescribed blood flow rate affects the rate of which process during hemodialysis?

• A. Filtration
• B. Diffusion
• C. Osmosis
• D. Ultrafiltration

Answer: (B)

Lowering the blood flow rate reduces how much blood carrying solutes reaches the dialyzer each minute. Diffusion relies on solute molecules moving across the membrane from higher to lower concentration, and the amount that can cross per unit time depends on how much solute-bearing blood is delivered to the dialyzer. With less blood flow, fewer solutes are available at the membrane per moment, so the rate at which small solutes (like urea and creatinine) diffuse into the dialysate decreases. Osmosis and ultrafiltration are driven more by water movement due to osmotic and hydrostatic pressures, respectively, and are not as directly affected by changes in blood flow into the dialyzer.

Lowering the blood flow rate reduces how much blood carrying solutes reaches the dialyzer each minute. Diffusion relies on solute molecules moving across the membrane from higher to lower concentration, and the amount that can cross per unit time depends on how much solute-bearing blood is delivered to the dialyzer. With less blood flow, fewer solutes are available at the membrane per moment, so the rate at which small solutes (like urea and creatinine) diffuse into the dialysate decreases. Osmosis and ultrafiltration are driven more by water movement due to osmotic and hydrostatic pressures, respectively, and are not as directly affected by changes in blood flow into the dialyzer.