No “optimal timing” of renal-replacement therapy in critically ill patients with acute kidney injury

Acute kidney injury (AKI) represents a sudden decrease in renal function from a number of disparate causes (1). Using KDIGO (Kidney disease: Improving Global Outcomes) definition, a meta-analysis indicated that the world incidence rates of AKI were approximately 21% in adults and 33% in children (2). Acute tubular necrosis (ATN) accounts for the majority cases of AKI especially in critical care setting with mortality rate exceeding 50% (3). The current medical management of AKI/ATN, however, is limited to supportive care and renal-replacement therapy (RRT) if indicated, while various therapeutic modalities have been attempted without success.