Intercompartmental Fluid Shifts in Hemodialysis Patients

Abstract

Abstract Hemodialysis is a therapeutic procedure for replacing some functions of the natural kidney. As such, it is capable of allowing people with little or no residual kidney function to survive and in some cases to lead productive lives. There are, unfortunately, a number of side effects associated with this procedure (shock, muscle cramps, fatigue, etc.). In order to minimize these side effects, we have undertaken to model shifts of fluid between the intracellular and extracellular fluid spaces in hemodialysis patients. Fluid shifts are primarily a function of osmolality differences between these fluid spaces. Changes in osmolality are caused mainly by changes in urea and salt concentrations. Least squares analysis of patient data has been used to estimate the appropriate ultrafiltration and urea mass transfer coefficients for each patient. The model has then been used to find a dialysate sodium concentration profile that will minimize fluid shifts into and out of the intracellular fluid space.