title: Effect of lowering dialysate sodium concentration on interdialytic weight gain and blood pressure in patients undergoing thrice-weekly in-center nocturnal hemodialysis: a quality improvement study.
abstract: BACKGROUND
  Patients on in-center nocturnal hemodialysis therapy typically experience higher interdialytic weight gain (IDWG) than patients on conventional hemodialysis therapy. We determined the safety and effects of decreasing dialysate sodium concentration on IDWG and blood pressure in patients on thrice-weekly in-center nocturnal hemodialysis therapy.
  
  
  METHODS
  Quality improvement, pre-post intervention.
  
  
  METHODS
  15 participants in a single facility.
  
  
  METHODS
  Participants underwent three 12-week treatment phases, each with different dialysate sodium concentrations, as follows: phase A, 140 mEq/L; phase B, 136 or 134 mEq/L; and phase A(+), 140 mEq/L. Participants were blinded to the exact timing of the intervention.
  
  
  RESULTS
  IDWG, IDWG/dry weight (IDWG%), and blood pressure.
  
  
  METHODS
  Outcome data were obtained during the last 2 weeks of each phase and compared with mixed models. The fraction of sessions with adverse events (eg, cramping and hypotension) also was reported.
  
  
  RESULTS
  IDWG, IDWG%, and predialysis systolic blood pressure decreased significantly by 0.6 ± 0.6 kg, 0.6% ± 0.8%, and 8.3 ± 14.9 mm Hg, respectively, in phase B compared with phase A (P < 0.05 for all comparisons). No differences in predialysis diastolic and mean arterial or postdialysis blood pressures were found (P > 0.05 for all comparisons). The proportion of treatments with intradialytic hypotension was low and similar in each phase (P = 0.9). In phase B compared with phase A, predialysis plasma sodium concentration was unchanged (P > 0.05), whereas postdialysis plasma sodium concentration decreased by 3.7 ± 1.9 mEq/L (P < 0.05).
  
  
  CONCLUSIONS
  Modest sample size.
  
  
  CONCLUSIONS
  Decreasing dialysate sodium concentrations in patients undergoing thrice-weekly in-center nocturnal hemodialysis resulted in a clinical and statistically significant decrease in IDWG, IDWG%, postdialysis plasma sodium concentration, and predialysis systolic blood pressure without increasing adverse events. Prolonged exposure to higher than required dialysate sodium concentrations may drive IDWG and counteract some of the purported benefits of "go-slow" (longer session length) hemodialysis.
authors.affiliation: Department of Medicine, Division of Nephrology, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Jair
authors.initials: J
authors.lastname: Munoz Mendoza
authors.forename: Liz Y
authors.initials: LY
authors.lastname: Bayes
authors.forename: Sumi
authors.initials: S
authors.lastname: Sun
authors.forename: Sheila
authors.initials: S
authors.lastname: Doss
authors.forename: Brigitte
authors.initials: B
authors.lastname: Schiller
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D015314:Dialysis Solutions / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058996:Quality Improvement; D006435:Renal Dialysis / Q000379:methods; D016037:Single-Blind Method; D012964:Sodium / Q000032:analysis* / Q000097:blood; D015430:Weight Gain / Q000502:physiology*
chemical_list: D015314:Dialysis Solutions; D012964:Sodium