Grant: Project Grant

Patients with critical illness are often afflicted with acute kidney injury (AKI). A large proportion of these sick patients require treatment with acute dialysis therapy, usually in the form of continuous renal replacement therapy (CRRT). Current clinical practice guidelines recommend patients receive this CRRT at a relatively fixed dose based on capacity for clearing small molecules from the blood (recommended dose 25-30 mL/kg/hr). Prior studies evaluated even higher CRRT doses and found no incremental benefit. To date, no study has evaluated the minimally acceptable CRRT dose or whether a lower CRRT dose, after a period of initial stabilization, is acceptable or even superior. This is an important knowledge gap. There is a strong rationale to evaluate this for several reasons: 1) acute CRRT is invasive, resource intensive and expensive; 2) recent evidence implies that higher CRRT dose can prolong duration of treatment with dialysis; 3) recent evidence further suggests that lower CRRT dose has similar efficacy and is safe; 4) concern that higher CRRT dose may plausibly cause unmeasured harm (excess removal of vital electrolytes, micronutrients, drugs), 5) concern that excess CRRT dose needlessly adds to costs and resources and has a negative impact on the environmental. This proposal outlines a multi-centre pilot randomized feasibility trial comparing lower CRRT dose to the current standard (guideline-directed) CRRT dose in 100 critically ill patients with acute kidney injury admitted to intensive care. Evidence on the optimal CRRT dose is lacking. The minimally acceptable CRRT dose is an important knowledge gap and needs a rigorous RCT to inform best practice and to update clinical practice guidelines. The current recommended standard may contribute unintended harm and needless use of resources. This proof-of-concept pilot trial will be a vital precursor for a larger definitive multi-centre trial that will be focused on patient-relevant endpoints.