One of the problems in hemodialysis is the occurrence of disequilibrium syndrome such as headache and vomitting during the treatment. The increase in the difference of osmotic pressures between intra- and extra-cellular fluids due to the rapid reduction in blood osmosis after starting hemodialysis has been considered as the major cause. For combating this problem, various means have been employed: short and frequent hemodialysis for the patients in the dialysis introductory stage; reduced blood and dialysate flows; and minimization of the difference in osmotic pressures by decreasing removal rates of end-products of metabolism by means of a recirculating system.
Presently, the equipment in which time-course change in the osmotic pressure of dialysate as well as the volume of fluid removal can be controlled was developed. The controller was aimed for lessoning disequilibrium syndrome by decreasing the difference in the osmotic pressures between intra-and extra-cellular fluids. It enables us to control changes in the blood osmotic pressure of hemodialysis patients by the regulation of dialysate osmotic pressure. In addition, the volume of fluid removal can be controlled and a pre-determined volume can be eliminated at the end of dialysis. With this equipment, the dialyzer can be prescribed according to the purpose of therapy, as the troublesome requirement for the regulation of pressure at the time of dialyzer exchange was omitted
