High Versus Low Bicarbonate Bath in Critically-ill Patients Receiving Continuous Renal Replacement Therapy

Researchers are trying to determine which dialysis solution, low bicarbonate fluid (22 mmol/L) or high bicarbonate fluid (32 mmol/L), is better in subjects with acute kidney injury (acute kidney failure) and metabolic acidosis that are admitted to the intensive care unit and require continuous renal replacement therapy (also known as continuous dialysis).

This is a prospective randomized trial that will be conducted at Mayo Clinic in Rochester Minnesota. It will be based on Good Clinical Practice Standards and performed under IRB supervision. This will be a pragmatic clinical trial due to the nature of the intervention and short interval for making a clinical decision. While dialysis in general is valid in cases of severe AKI and metabolic acidosis, there remains uncertainty as to which replacement fluid to use. In one retrospective study, using high bicarbonate replacement fluid was associated with worse outcomes, even after accounting for several important confounders. While this intervention is valid in cases of severe metabolic acidosis (pH\<7), there has not been much data to support the use of either intervention in cases of any metabolic acidosis in general. While both interventions are equally valid, to our knowledge, there is no randomized clinical trial evaluating the difference of either intervention on outcomes. There is limited evidence in the literature on benefit or harm associated with either of the interventions on the outcomes thus generating a clinical equipoise. This pivotal study should help guide nephrologists and intensivists on the appropriate prescription of CRRT.