None listed
Conditions
Brief summary
End stage kidney disease is increasing in incidence and many patients in Australia and New Zealand require renal replacement therapy. In 2014, 9147 patients were managed with haemodialysis (HD), and an additional 2207 patients were on haemodiafiltration (HDF) (ANZDATA 2016). Although the uptake of HDF relative to HD has increased considerably, HDF remains underutilized in Australia, especially when compared to uptake in Europe and some parts of Asia. HD performs solute clearance and volume removal by the process of diffusion, with minimal contribution from convection. HDF enhances small and middle molecule clearance through convection and diffusion, which may theoretically improve patient-level clinical outcomes. The safety of HDF has been confirmed by recently published meta-analysis. Solute clearance by convection requires substantial volumes of ultrafiltration, which in turn necessitates the administration of exogenous fluid replacement. This fluid has traditionally been reinfused either before (pre-dilution HDF) or after (post-dilution HDF) the dialyser. Post-dilution HDF is highly efficient in terms of solute clearance, but concerns have been raised regarding haemoconcentration with an increase in theoretical risk of clotting. Pre-dilution HDF minimizes the risk of haemoconcentration but provides less efficient solute removal. In recent years, two novel HDF techniques (mixed- and mid-dilution HDF) have been developed, which permit simultaneous pre- and post-dilution delivery. Mixed-dilution HDF appears to offer the most optimal balance between solute clearance efficiency and haemoconcentration compared to other forms of HDF. However, its uptake has been limited in Australia in spite of its availability. Few studies have assessed the clinical efficacy of mixed dilution HDF. Existing literature is limited by small patient numbers and limited outcome measures. This randomised crossover trial will compare convection volume, clotting, small/middle/large molecule clearance, circuit clotting and post dialysis recovery time between mixed and post dilution HDF
Interventions
Mixed dilution haemodiafiltration (HDF) is the intervention in this trial and post-dilution HDF is the control. Currently, dialysis patients are routinely managed with post-dilution HDF in the units in this study (which is consistent with other units who perform HDF in Australia and New Zealand). HDF involves large volumes of fluid convection (the primary mechanism of solute clearance) and, subsequently, large volumes of replacement fluid reinfusion. In post-dilution HDF, replacement fluid is re
Mixed dilution haemodiafiltration (HDF) is the intervention in this trial and post-dilution HDF is the control. Currently, dialysis patients are routinely managed with post-dilution HDF in the units in this study (which is consistent with other units who perform HDF in Australia and New Zealand). HDF involves large volumes of fluid convection (the primary mechanism of solute clearance) and, subsequently, large volumes of replacement fluid reinfusion. In post-dilution HDF, replacement fluid is reinfused after the dialysis membrane. In mixed-dilution HDF, replacement fluid is reinfused both before and after the dialysis membrane in a ratio that will allow the most efficient clearance of solutes while maintaining a safe transmembrane pressure (TMP, the pressure between the dialysis fluid and blood compartments). The ratio is controlled automatically by the dialysis machine to maintain TMP between 250 - 300 mmHg. Apart from the site of fluid replacement, no other dialysis parameters will differ from standard care (ie post-dilution HDF) After screening, patients will be randomised 1:1 to arm A (mixed then post dilution HDF) or arm B (post dilution then mixed HDF). Following a 2 week run in period of post-dilution HDF, patients will commence the first of two 4 week intervention periods. These intervention periods will be separated by a 2 week washout period of post-dilution HDF. In the intervention periods, patients will continue on their pre-trial dialysis session duration, treatment location and dialysis schedule (Monday/Wednesday/Friday or Tuesday/Thursday/Saturday). Dialysate composition will remain constant. Each session, convection volume, circuit clotting and peak transmembrane pressure will be recorded by dialysis nursing staff. In the final week of each intervention period, pre and post dialysis bloods (solute clearance, albumin and clotting) and a post-dialysis recovery time questionnaire will be performed.
Sponsors
Princess Alexandra Hospital
Study design
Allocation
Randomised controlled trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Patients with end stage kidney disease on conventional in-centre haemodialysis with dialysis session duration 4-6hr, three times per week
Exclusion criteria
Incident haemodialysis patients (<3 months), Temporary vascular access (HD central venous catheter) Life expectancy <6 months Medical instability –altered response criteria (airway, breathing, circulation, neurology) Blood flow rate (Qb) <250mls/min Non-adherence to prescribed treatment hours Unable to tolerate post-dilution HDF Residual urine output >500ml/day
Outcome results
None listed