Timing or Modality of Renal Replacement Therapies in Critically Ill Patients

The use of renal replacement therapies (RRT) in critically ill patients has changed the prognosis of acute kidney injury in these patients over the last 30 years. However, many questions remain unanswered especially those concerning when to start RRT (timing) and which modality should be selected. Early strategies referred to timing have been encouraged in critically ill patients in the last two decades based on clinical experiences but not randomized controlled trials (RCT). Two recent RCT seem to support a delayed strategy in patients with AKI who do not present a lifethreatening fluid overload condition.