| [ Summary ] |
Hemodiafiltration (HDF), a combination of hemodialysis (HD) and hemofiltration (HF), can be performed in a variety of ways. Technical specifications for diafilters require individual HDF treatments vary from patient to patient. Since blood flow rates are high in pre-dilution HDF treatments, higher-flux membranes with larger pore sizes are required. In post-dilution HDF, ultrafiltration coefficients may be secured by increasing the surface area of membranes because higher pore sizes may lead to a large amount of albumin loss. A module design for both pre- and post-dilution may be relatively large in diameter and short in length in order to avoid high pressures. We expect to maintain the ultrafiltration coefficients with pre-dilution and to provide higher clearances with post-dilution in simultaneous pre- and post-dilution HDF. The development of concentration polarization on membranes may be disturbed in push and pull HDF. Internal filtration may be enhanced by employing several different techniques. Since several liters of internal filtration may be expected by the use of so-called super high flux dialyzers (spcified as class 4 and 5 in the Japanese reimbursement system), the use of ultra pure dialysis fluid may be predominantly required. |