Clinical evaluation of a pre-set ultrafiltration rate controller available for single pass and hemodiafiltration...

Introduction of high flux-type dialyzers, such as the RP-6, makes it necessary to devise an ultrafiltration rate controller for a single pass system. For this purpose, a new pre-set ultrafiltration rate controller has been developed and examined experimentally and clinically. The controller has twin chambers, each of which is divided into two symmetrical parts by a vertically-placed diaphragm. The diaphragm shifts repeatedly from right to left, aspirating in and driving out fresh or used dialysate alternately. If one removes a certain amount of used dialysate from a branch of the efferent line, negative pressure develops and aspirates an equal amount of water from the dialyzer. Therefore, extra dialysate obtained by a pump precisely reflects ultrafiltration rate. The controller has been used on five patients. The scheduled ultrafiltration rate was easily obtainable. The apparatus is also available for hemodiafiltration. Initial clinical trial has been promising.