[Paired filtration dialysis--evaluation of effectiveness of the method]

Paired filtration dialysis (PFD) is a haemodiafiltration method which uses in a major way the convection as well as the diffusion principle of blood clearance. It is the only method replacing renal function where blood filtration is separated from diffusion. The objective of the study is to make the medical community familiar with this method and to assess the effectiveness of PFD when two types of haemodiafilters are used. The effectiveness of PFD is also compared with haemodialysis where a highly permeable haemofilter is used (high-flux haemodialysis, HFHD) with a medium-size area. A group of 8 dialyzed patients was treated after weekly intervals by PFD in two set-ups: 1. PFD with a haemodiafilter SG3 (high-flux polysulphon haemofilter and a low-flux haemophan dialyzer, area 0.55 m2 and 1.36 m2). 2. PFD with haemodiafilter SG30 (high-flux polysulphon haemofilter and low-flux polysulphon dialyzer, area 0.55 m2 and 1.36 m2). The author used also HFHD with a polyacrylonitrile membrane AN 69 (Filtral 12, area 1.3 m2). The index of the dialyzation dose Kt/V was higher in PFD, similarly as the clearance of creatinine, urea, phosphates and uric acid. Beta-2-microglobulin was investigated as a representative of medium-sized molecular substances. Beta-2-microglobulin was eliminated in HFHD and PFD, HFHD being most effective. The selected variants of PFD replace effectively the excretory renal function. The effectiveness of PFD is in particular due to the large total area of the haemodiafilter. According to the authors the standard length of the procedure for a patient with a mean height at a rate of 300 ml/min. is 4 hours. PFD eliminates also beta-2-microglobulin similarly (SG3) or less (SG30) than HFHD with membrane AN 69 with a medium-sized area.