Haemodialysis with low dialysate flow rates: A comparison of high performance membranes and conventional membranes

Summary: We performed experimental studies to examine the effects of low dialysate flow rates on the clearance of small molecular weight substances, a middle molecular weight substance and a low molecular weight protein using a high performance membrane (HPM) and a conventional membrane (CVM). the blood flow rate was 200 mL/min and the diasylate flow rate varied between 300 and 500 mL/min. Clearance of urea and creatinine, representing small molecular weight substances, clearance of vitamin B12 representing a middle molecular weight substance, and clearance of myoglobin, representing a middle molecular weight substance, and clearance of myoglobin, representing a low molecular weight protein were measured. Lowering the dialysate flow rate from 500 to 300 mL/min in the HPM decreased the clearance of urea, creatinine, vitamin B12 and myoglobin by 7.2%, 8.6%, 8.4%, and 2.4%, respectively. Lowering the dialysate flow rate from 500 to 300 mL/min in the CVM decreased the clearance of urea, creatinine, and vitamin B12 by 8.7%, 10.9%, and 10.4%, respectively. Changes in the clearance of creatinine with reduced dialysate flow rate in the HPM were significantly lower than those in the CVM (P<0.05). Clearance of urea, creatinine, and vitamin B12 in the HPM at a dialysate flow rate of 300 mL/min were higher than those of in the CVM at a dialysate flow rate of 500 mL/min. These results suggest that dialysate flow rates can be reduced and water can be effectively saved by combining a dialysate flow rate of 300 mL/min with a HPM during water shortages due to natural disasters or climate changes.