title: Haemodiafiltration results in similar changes in intracellular water and extracellular water compared to cooled haemodialysis.
abstract: OBJECTIVE
  Intradialytic hypotension is the most common complication of modern day haemodialysis (HD). Convective modalities, including haemodiafiltration (HDF) are reported to result in greater cardiovascular stability compared to standard HD, which has been suggested to be due to improved solute transport between compartments. We therefore investigated the effect of treatment on body water by bioimpedance.
  
  
  METHODS
  We measured the change in extracellular water (ECW) and intracellular water (ICW) in 263 outpatients attending for HD using cooled dialysate and 134 patients for HDF.
  
  
  RESULTS
  Patient cohorts were matched for demographics, dialysate composition, ultrafiltration rate, and session duration. The fall in systolic blood pressure following HD was -11.8 mm Hg (-25.3 to 2.3) and not different from that following HDF -12 mm Hg (-27 to 6). Similarly there were no differences in pretreatment serum sodium and dialysate sodium gradient [HD 1 mmol/l (-1 to 3) vs. HDF 2 mmol/l (1 to 4)], or change in serum sodium posttreatment [HD 0 mmol/l (-2 to 2) vs. HDF 1 mmol/l (-1 to 3)]. There were no differences in ICW or ECW pretreatment, and following treatment the reduction in ICW and ECW did not differ [ICW HD -3.5% (-5.7 to -1.8) vs. -4.1% (-6.0 to -1.7), ECW HD -7.1% (-9.4 to -4.7) vs. HDF -7.1% (-9.7 to -4.9)].
  
  
  CONCLUSIONS
  We were unable to demonstrate any advantage for HDF over HD using cooled dialysate in terms of changes in blood pressure during a treatment session, or differences in the relative changes in ICW or ECW volumes.
authors.affiliation: UCL Centre for Nephrology, Royal Free Hospital, University College London Medical School, London, UK.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Kumar
authors.forename: Maryam
authors.initials: M
authors.lastname: Khosravi
authors.forename: Annick
authors.initials: A
authors.lastname: Massart
authors.forename: Madhu
authors.initials: M
authors.lastname: Potluri
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
mesh_terms: D000328:Adult; D001794:Blood Pressure; D001834:Body Water / Q000502:physiology*; D003080:Cold Temperature; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000502:physiology*; D005260:Female; D017583:Hemodiafiltration; D006801:Humans; D007424:Intracellular Fluid / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000379:methods