title: Pre to post-dialysis plasma sodium change better predicts clinical outcomes than dialysate to plasma sodium gradient in quotidian hemodialysis.
abstract: Sodium balance across a hemodialysis treatment influences interdialytic weight gain (IDWG), pre-dialysis blood pressure, and the occurrence of intradialytic hypotension, which associate with patient morbidity and mortality. In thrice weekly conventional hemodialysis patients, the dialysate sodium minus pre-dialysis plasma sodium concentration (δDPNa+) and the post-dialysis minus pre-dialysis plasma sodium (δPNa+) are surrogates of sodium balance, and are associated with both cardiovascular and all-cause mortality. However, whether δDPNa+ or δPNa+ better predicts clinical outcomes in quotidian dialysis is unknown. We performed a retrospective analysis of clinical and demographic data from the Southwestern Ontario Regional Home Hemodialysis program, of all patients since 1985. In frequent nocturnal hemodialysis, δPNa+ was superior to δDPNa+ in predicting IDWG (R(2)=0.223 vs. 0.020, P=0.002 vs. 0.76), intradialytic change in systolic (R(2)=0.100 vs. 0.002, P=0.02 vs. 0.16) and diastolic (R(2)=0.066 vs. 0.019, P=0.02 vs. 0.06) blood pressure, and ultrafiltration rate (R(2)=0.296 vs. 0.036, P=0.001 vs. 0.52). In short hours daily hemodialysis, δDPNa+ was better than δPNa+ in predicting intradialytic change in diastolic blood pressure (R(2)=0.101 vs. 0.003, P=0.02 vs. 0.13). However, δPNa+ was better than δDPNa+ in predicting IDWG (R(2)=0.105 vs. 0.019, P=0.04 vs. 0.68) and pre-dialysis systolic blood pressure (R(2)=0.103 vs. 0.007, P=0.02 vs. 0.82). We also found that the intradialytic blood pressure fall was greater in frequent nocturnal hemodialysis patients than in short hours daily patients, when exposed to a dialysate to plasma sodium gradient. These results provide a basis for design of prospective trials in quotidian dialysis modalities, to determine the effect of sodium balance on cardiovascular outcome.
authors.affiliation: Division of Nephrology, Department of Medicine, London Health Sciences Centre and Western University, London; Department of Medical Biophysics, Western University, London; Kidney Clinical Research Unit, London Health Sciences Center, London.
authors.forename: Benjamin K A
authors.initials: BK
authors.lastname: Thomson
authors.forename: Shih-Han S
authors.initials: SH
authors.lastname: Huang
authors.forename: Rosemary E
authors.initials: RE
authors.lastname: Leitch
authors.forename: Stephanie
authors.initials: S
authors.lastname: Dixon
authors.forename: Paul
authors.initials: P
authors.lastname: Heidenheim
authors.forename: Rita S
authors.initials: RS
authors.lastname: Suri
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Chan
authors.forename: Robert M
authors.initials: RM
authors.lastname: Lindsay
mesh_terms: D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D015312:Hemodialysis Solutions / Q000008:administration & dosage*; D006437:Hemodialysis, Home / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007022:Hypotension / Q000209:etiology; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods*; D012964:Sodium / Q000097:blood*; D016896:Treatment Outcome; D015430:Weight Gain / Q000187:drug effects
chemical_list: D015312:Hemodialysis Solutions; D012964:Sodium
keywords: Home hemodialysis; blood pressure; dialysate sodium; interdialytic weight gain; intradialytic hypotension; plasma sodium