Background: Bicarbonate (i.e. baking soda) is added to hemodialysis fluids to correct the high level of acid in the blood that arises from kidney failure. Some dialysis units in Canada add bicarbonate to a level of 32 mmol/L, while other units add bicarbonate to a level of 38 mmol/L. It is unknown whether one level is better for people’s health.

Objective: To determine if providing a lower versus higher concentration of dialysate bicarbonate (32 versus 38 mmol/L) alters the risk of outcomes important to patients and their care providers.   

Randomization: Patients will be randomly assigned to a dialysate bicarbonate concentration of 32 mmol/L, or 38 mmol/L based on the last digit of their OHIP number. Both of these bicarbonate concentrations are currently used in dialysis units across Ontario.

Design, Setting, and Participants: This is a pragmatic, two-arm, parallel-group, open-label, individual-randomized, superiority trial that will be conducted in hemodialysis units across Ontario. This trial is “embedded” in routine care, meaning patients are participating in the trial during their usual dialysis session and the intervention is delivered by hemodialysis unit personnel. The concentration of dialysate bicarbonate is altered for a hemodialysis session through a simple setting on the machine.

Consent: Dial-Bicarb met the following Tri-Council Policy Statement (TCPS2) criteria for a waiver of consent to apply the intervention and collect data; 1) minimal risk to participants, 2) altered consent is unlikely to adversely affect patients, 3) trial can not practically be carried out without an alteration to the consent, 4) there is a plan to inform patients about the trial. Patients will receive a flyer from dialysis unit personnel during their routine visits to the dialysis unit. The trial flyer is available in several translated languages and can be found here.

Primary outcome: All-cause mortality and all-cause non-elective hospitalizations.

Other outcomes: Cardiovascular-related hospitalizations, infection-related hospitalizations, and fractures.   

Data Collection: This trial will obtain information on patient characteristics and outcomes from provincial healthcare administrative databases, information that is already collected as part of routine healthcare.  

Potential Impact: If a lower concentration of dialysate bicarbonate is shown to be superior, it could be easily adopted as the standard of care by hemodialysis units globally at no added cost. This change in practice could help reduce hospitalizations and premature deaths among the more than 2 million people on hemodialysis worldwide.