May an “Early” renal replacement therapy improve survival?

Renal replacement therapy (RRT) is the main supportive treatment for acute kidney injury (AKI). A meta-analysis suggested that “early” RRT could offer a survival advantage. However, there is no consensus about the criteria for optimal timing to start RRT in critically ill patients, as well as about what “early” exactly means. The cause of AKI is probably an important factor to be considered in deciding when to start the treatment: if RRT could help to treat the cause of AKI, as in sepsis or in acute respiratory distress syndrome, then an early initiation may be more useful than a late or “conventional” approach.