A computerized model to analyze transcellular fluid shift during hemofiltration.
Using urea and inulin as markers, we have developed a simple method to calculate intracellular and extracellular fluid volume in patients before and after hemofiltration therapy. During conventional hemofiltration using substitution fluid with a Na+ concentration of 140 mEq/L, a decrease in extracellular fluid volume was noted whereas the intracellular fluid volume was unaltered. Furthermore, we have developed a computerized mathematical model to analyze transcellular fluid shifts during hemofiltration. This model also indicates a decrease in extracellular fluid volume only, the intracellular fluid volume remaining unchanged. High-Na+ hemofiltration using substitution fluid with an Na+ concentration of 160 mEq/L has enabled us to remove fluid from both intracellular and extracellular compartments. Thus, high-Na+ hemofiltration is expected to normalize the intracellular hydration in uremic patients, and to reduce the decrease in extracellular fluid volume during hemofiltration therapy. Our data therefore suggest that high-Na+ hemofiltration could prevent hypotension due to large decreases in extracellular fluid volume by inducing a transcellular fluid shift out of body cells. Our computerized model can be a useful tool in the prescription of the optimal Na+ concentration in substitution fluid for individualized hemofiltration therapy.
D000328:Adult; D001692:Biological Transport; D001769:Blood; D001826:Body Fluids / Q000502:physiology; D003201:Computers; D005110:Extracellular Space / Q000502:physiology; D005260:Female; D006801:Humans; D007424:Intracellular Fluid / Q000502:physiology; D008433:Mathematics; D008954:Models, Biological; D012964:Sodium / Q000097:blood; D014462:Ultrafiltration / Q000379:methods*
D012964:Sodium