Comparison of two dialysis modes: nocturnal haemodialysis (NHD) and haemodiafiltration (HDF) in haemodialysis patients.

INTERVENTION: 2X2 Crossover study ‐ comparison of 2 different dialysis membranes plus comparison of NHD vs HDF. Baseline status (prior to first study treatment): Nocturnal haemodialysis (8 hour sessions, 3.5x per week) ‐ performed at home, using Fresenius Cordiax dialysers. Randomisation 1: randomised to either remain on the Fresenius Cordiax dialysers OR to change to Nipro Elisio dialysers ‐ of similar surface area. Randomisation 2: enter cross‐over trial of either NHD followed by HDF or vice versa; both with a 2 week washout (regular nocturnal HD) in between. The study session will be the last dialysis session of each 2‐week study period (NHD and HDF): for NHD this study session will be performed in the Home training unit. Trial comparator: Haemodiafiltration (4 hour sessions, 3x per week) ‐ performed in the Home Dialysis Training Unit under nurse supervision. Study periods are 2 weeks each, with the last session in the 2‐week period being the tested session. There is a 2 week washout between the two periods, wherein patients return to their baseline (NHD) treatment pattern. For the 2‐week NHD study period, patients will have 3x per week dialysis (rather than 3.5x) to allow closer comparison. CONDITION: haemodialysis PRIMARY OUTCOME: dialysate based assessment of removal of urea and phosphate serum biochemical parameters of dialysis adequacy (urea, phosphate, B2microglobulin, retinol binding protein, fetuin, FGF‐23, alpha‐1 microglobulin) as a composite outcome SECONDARY OUTCOME: cardiovascular stability ‐ as assessed by blood pressure during dialysis. INCLUSION CRITERIA: existing nocturnal haemodialysis patients have been stable on NHD for at least 3 months permanent vascular access