Experimental Studies on Dialysate Free Artificial Kidney -DIFAK

One of the major obstacles impeding the further expansion of chronic hemodialysis in Japan is that hemodialysis equipments are too big and also hard to handle . So we think that smaller and more easily handled equipments are needed. It is necessary to make dialysate volume lower in making a smaller equipment. A dialysate regenerating system is indispensable to make such equipments. So we have studied on a dialysate regenerating system using several adsorbents. We have carried on the research of adsorbents such as activatedd charcoal, aluminum oxide, magnesium oxide, kaolin, bone charcoal and ion exchanges. Above these 6 adsobents were examined with ultrafiltrates through SCUM, obtained from uremic patients. Aluminum oxide and magnesium oxide adsorbed inorganic phosphate efficiently and we though that activated charcoal was an excellent adsorbent. However no adsorbents adsorbed urea efficiently. As one step towards DIFAK, we have tried to make a machine incorporated with 301 of dialysate, activated charcoall and aluminum oxide. 301 of dialysate is almost the same volume as human body fluid. Theoretically, when the resistance of the membrance is neglected, the serum urea concentrations of the patients become half after dialysis using 301 of dialysate. Creatinine and uric acid might be removed efficiently by using activated charcoal. Inorganic phosphate might be removed by using aluminum oxide. The removal rates of substances in uremic patients were measured in conventional hemodialysis andd hemodialysis using 301 of dialysate. The removal rates of substances which are larger than 300 in moecular weight in 30l-dialysate-dialysis are the same as those of conventional hemodialysis. But the removal rates of the substances smaller than 300 in molecular weight in 301 dialysate dialysis are worse than conventional hemodialysis. But small molecular subtances such as creatinine and uric acid, couldd be removed efficiently by activated charcoal. So we believed that our new equipment -DIFAK- incorporated with 301 of dialysate, activatedd charcol and aluminum oxide is beneficial to making a small equipment.