title: High versus low dialysate sodium concentration in chronic haemodialysis patients: a systematic review of 23 studies.
abstract: It is the object of debate whether a low or high dialysate sodium concentration (DNa(+)) should be advocated in chronic haemodialysis patients. In this paper, we aimed at evaluating benefits and harms of different DNa(+) prescriptions through a systematic review of the available literature.
  
  
  
  MEDLINE and CENTRAL databases were searched for studies comparing low or high DNa(+) prescriptions. Outcomes of interest were mortality, blood pressure (BP), interdialytic weight gain (IDWG), plasma sodium, hospitalizations, use of anti-hypertensive agents and intradialytic complications.
  
  
  
  Twenty-three studies (76 635 subjects) were reviewed. There was high heterogeneity in the number of patients analysed, overall study quality, duration of follow-up, DNa(+) and even in the definition of 'high' or 'low' DNa(+). The only three studies looking at mortality were observational. The risk of death was related to the plasma-DNa(+) gradient, but was also shown to be confounded by indication from the dialysate sodium prescription itself. BP was not markedly affected by high or low DNa(+). Patients treated with higher DNa(+) had overall higher IDWG when compared with those with lower DNa(+). Three studies reported a significant increase in intra-dialytic hypotensive episodes in patients receiving low DNa(+). Data on hospitalizations and use of anti-hypertensive agents were sparse and inconclusive.
  
  
  
  There is currently no definite evidence proving the superiority of a low or high uniform DNa(+) on hard or surrogate endpoints in maintenance haemodialysis patients. Future trials adequately powered to evaluate the impact of different DNa(+) on mortality or other patient-centred outcomes are needed.
authors.affiliation: Division of Nephrology, Miulli General Hospital, Acquaviva delle Fonti, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Basile
authors.affiliation: CNR- Institute of Clinical Physiology, Reggio Calabria, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Pisano
authors.affiliation: Division of Nephrology, Miulli General Hospital, Acquaviva delle Fonti, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Lisi
authors.affiliation: Division of Nephrology, Miulli General Hospital, Acquaviva delle Fonti, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Rossi
authors.affiliation: Division of Nephrology, Miulli General Hospital, Acquaviva delle Fonti, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Lomonte
authors.affiliation: CNR- Institute of Clinical Physiology, Reggio Calabria, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Bolignano
mesh_terms: D001794:Blood Pressure; D002908:Chronic Disease; D015314:Dialysis Solutions / Q000378:metabolism*; D004039:Diet, Sodium-Restricted; D006760:Hospitalization; D006801:Humans; D017063:Outcome Assessment, Health Care; D006435:Renal Dialysis; D012964:Sodium / Q000097:blood*; D015430:Weight Gain
chemical_list: D015314:Dialysis Solutions; D012964:Sodium
keywords: blood pressure; dialysate sodium concentration; haemodialysis; interdialytic weight gain; intradialytic complications; mortality