The Timing of Renal Replacement Therapy Initiation in Acute Kidney Injury

The optimal time to start renal replacement therapy (RRT) in the setting of acute kidney injury (AKI) is one of the most controversial questions in the field of critical care nephrology. An earlier or pre-emptive approach, whereby RRT is initiated in the absence of a life-threatening complication of AKI, may have a variety of plausible benefits. On the other hand, the widespread adoption of such an approach would consume more resources and would have to be justified by evidence of superior patient outcomes. It is possible that a more conservative strategy that reserves the initiation of RRT until an urgent indication is present might confer acceptable patient outcomes without exposing patients who are destined to recover from AKI spontaneously to the risks of unnecessary RRT. Ongoing randomized controlled trials should help bring clarity to this important area of clinical uncertainty.