title: Fluid dynamics during hemodialysis in relationship to sodium gradient between dialysate and plasma.
abstract: Fluid shifts during hemodialysis involve changes in both extracellular and intracellular volumes. This study aimed to determine the effect of intradialytic sodium gradients (GNa), that is, the difference between dialysate and serum sodium concentration, on dynamics of extracellular and intracellular volumes in a group of maintenance hemodialysis patients. Extracellular volume change (deltaECV) between predialysis and postdialysis periods was determined by whole-body bioimpedance spectroscopy; intracellular volume change (deltaICV) was indirectly derived as the difference between deltaECV and the change in body weight, corrected for intradialytically given fluids. A total of 200 bioimpedance measurements were performed in 32 dialysis patients. Extracellular and intracellular volume changes were -2.6 +/- 0.9 L (range: -4.7 to -0.5 L) and -0.2 +/- 0.7 L (range: -2.5 to +1.5 L), respectively. There was a significant correlation between deltaICV and GNa; deltaICV = -0.12 * GNa + 0.26 (p < 0.001). In contrast, GNa was not correlated with deltaECV. We conclude that the sodium gradient between dialysate and plasma has a significant effect on the ICV during dialysis. Hemodialysis with GNa = 0 mmol/L should be sought to prevent ICV shrinking or swelling and to prevent excessive thirst, consequently high interdialytic weight gains, and ultrafiltration rates.
authors.affiliation: Weill Cornell Medical Center, New York-Presbyterian Hospital, New York, NY, USA.
authors.forename: Shubho R
authors.initials: SR
authors.lastname: Sarkar
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wystrychowski
authors.forename: Fansan
authors.initials: F
authors.lastname: Zhu
authors.forename: Len A
authors.initials: LA
authors.lastname: Usvyat
authors.forename: Peter
authors.initials: P
authors.lastname: Kotanko
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Levin
mesh_terms: D000328:Adult; D000368:Aged; D001826:Body Fluids / Q000378:metabolism*; D017097:Electric Impedance; D005110:Extracellular Space / Q000378:metabolism; D015312:Hemodialysis Solutions / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism* / Q000628:therapy*; D008875:Middle Aged; D008954:Models, Biological; D010949:Plasma / Q000378:metabolism; D006435:Renal Dialysis; D012964:Sodium / Q000378:metabolism*; D013894:Thirst; D014883:Water-Electrolyte Imbalance / Q000517:prevention & control; D015431:Weight Loss
chemical_list: D015312:Hemodialysis Solutions; D012964:Sodium