The sudden loss of renal function, previously known as acute renal failure, is now referred
to as acute kidney injury (AKI). It is characterized by increases in serum creatinine and
blood urea nitrogen levels. Urine output can be classifi ed as anuria (100 mL/day), oliguria
(100–400 mL/day), or nonoliguria (400 mL/day) (Kalista-Richards, 2011).