Hemodialysis prescription : dose adequacy by continuous monitoring of fresh and spent dialysate conductivity

Abstract

Measurement of hemodialysis treatment adequacy is essential to monitor quality assurance for today’s growing dialysis population. The universally accepted measure of hemodialysis dose is Kt/V. Kt/V above 1.2 has been shown to reduce patient morbidity and mortality. Currently, Kt/V is calculated from urea kinetic modelling using predialysis and postdialysis blood samples. This blood-based approach, as well as being costly and invasive, is typically performed once a month providing only periodic snapshots of dialysis adequacy. Methods to provide more frequent feedback to attending doctors have been developed based on urea concentration sensors in the spent dialysate stream. More recently, monitoring of dialysate conductivity in the spent dialysate stream has been proposed as an alternative to urea monitoring — ionic dialysance has been found to be highly correlated to urea clearance. The subject of this thesis is the kinetic modelling o f spent dialysate conductivity. The following single pool equation was developed to describe the kinetics of the spent dialysate conductivity during periods of constant inlet dialysate conductivity: (see document)