Definition

Acute Kidney Injury (AKI) is characterised clinically by a rapid reduction in kidney function resulting in a failure to maintain fluid, electrolyte and acid-base homeostasis. AKI is most commonly staged using the Acute Kidney Injury Network (AKIN) criteria (see table 1). Although initially developed as a research tool (to allow patients with AKI of a similar severity to be cohorted together), the criteria allow risk stratification of patients with AKI. However, their clinical utility is often less in the ED where the serum creatinine and urine output may not be available at the time of presentation.

Table 1. The AKIN criteria (1)