Mixed-dilution hemodiafiltration.
Mixed-dilution hemodiafiltration (mixed HDF) controlled by the transmembrane pressure (TMP) feedback, improves the depurative capacity of the more traditional HDF techniques by fully exploiting the convective mechanism of small- and middle-molecular-weight solute removal. The feedback allows the TMP to be set and profiled from patient and operational parameters recorded online by the machine. It automatically adjusts the infusion ratio between predilution and postdilution at the maximum filtration fraction without reducing the total infusion/ultrafiltration rate and taking into account fl ow conditions, internal pressures and hydraulic permeability of the dialyzer, and their complex interactions and changes during the session. The application of the TMP profile, while avoiding dangerous hydrostatic pressures within the dialyzer and their negative effects, helps better preserve the permeability of the membrane with the effect of a significantly increased solute removal in a wide molecular range and with minimal protein leakage. In the light of the more recent observations in the literature, the high biocompatibility resulting from the use of synthetic membranes and ultrapure dialysate, combined with the enhanced removal of small- and middle-molecular-weight uremic toxins obtained with high-efficiency HDF, seems to be the best available strategy to prevent or delay the occurrence of long-term dialysis complications and to promote improved survival of dialysis patients. Preliminary results of its application indicate that TMP-modulated mixed-dilution HDF could be one of the most powerful strategies to achieve this goal.
Nephrology and Dialysis Department, Bolognini Hospital of Seriate, Seriate, Italy.
Luciano A
LA
Pedrini
Simona
S
Zerbi
D017583:Hemodiafiltration / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D006874:Hydrostatic Pressure; D008567:Membranes, Artificial; D009862:Online Systems; D010539:Permeability
D008567:Membranes, Artificial