Acute kidney injury is de ned as an abrupt (within 48 hours) reduction in kidney func- tion based on an elevation in serum creati- nine level, a reduction in urine output, the need for renal replacement therapy (dialy- sis), or a combination of these factors. It is classi ed in three stages (Table 1).8 The term acute kidney injury should replace terms such as acute renal failure and acute renal insuf ciency, which previously have been used to describe the same clinical condition.