Indications and Timing of Renal Replacement Therapy

Renal replacement therapy (RRT) is an essential organ support platform for critically ill patients with acute kidney injury (AKI) and is increasingly utilized. The decision for when to optimally consider starting RRT can be challenging, owing to the necessity to balance perceived benefits and risks. For those patients developing severe AKI characterized by urgent indications, there is general agreement that RRT should be promptly started. However, for those patients without urgent indications, the optimal timing has been less certain and is susceptible to practice variation. The dilemma has centered around whether an early strategy (preemptive) of starting RRT can largely mitigate the hazards of AKI or whether a delayed strategy (conservative) where RRT is started in response to evolving urgent indications can translate into improved outcomes. Several recent clinical trials have provided insights into this dilemma but are not reflected in available clinical practice guidelines. In this chapter, recent evidence on timing of RRT will be appraised, integrating the spectrum of factors that may influence decision-making for RRT initiation.