The Role of Net Na and H2O Flux in the Morbidity of Hemodialysis and Hemofiltration

Of Sodium, Symptomatology and Syllogism

“…possible and even appropriate in the present instance [29], But such approaches do not often lead to quantitatively useful predictions and, in any event, seem well beyond the sophistication evidenced to date in publica tions supporting the disputed conclusion [25][26][27]. The second major objection occurs from the fact that all reports on the mecha nism of vascular stability in hemofiltration implicate an increase in peripheral resistance associated with an increase in circulating cat echolamines (and the failure of these two parameters to change in comparable hemo dialysis), whereas the sodium retention the ory operates in hemodialysis at least by im proving cardiac output presumably due to better refilling of the extracellular and vascu lar compartments, and this would not stimu late sympathetic activity and produce an in crease in catecholamines or a rise in periph eral resistance.…”

“…5) and com pared to a theoretical hemodialysis sodium flux calculated from a model [27] using the same operating parameters as were measured in hemofiltration, as it is impossible to mea sure sodium flux during conventional he modialysis at Qd 500 ml/min and differences in inlet and outlet dialysate sodium concen trations of less than the accuracy of even the most stringently controlled flame photome ters. The results [30] show essentially no dif ference in sodium flux between hemofiltra tion and hemodialysis for the operating con ditions described.…”

“…Recently, the proposition was advanced that the process of postdilutional hemofiltra tion was more sodium retentive than conven tional hemodialysis and that this improved sodium balance explained the better vascular stability during weight loss with treatment reported in postdilutional hemofiltration [25][26][27], It was noted that due to ultrafiltra-…”