Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android. Learn more here!


Definition of Acute Kidney Injury

Acute kidney injury (AKI) is a condition defined by an acute decrease in the glomerular filtration rate (GFR), resulting in dysregulation of volume, electrolytes, acid-base balance and inability to excrete metabolic waste products. The term AKI has replaced the older term acute renal failure (ARF) to highlight the varying degrees of renal dysfunction, to enable clinicians to recognize renal dysfunction earlier in the patient’s course, and to allow researchers to apply a uniform definition of acute renal dysfunction.1 The Acute Dialysis Quality Initiative (ADQI) and Acute Kidney Injury Network (AKIN) groups standardized the definition of AKI in adult patients based on the increase in serum creatinine (Cr) or oligoanuria, and the pediatric community has adopted modified criteria based on the ADQI and AKIN definitions (Table 42-1).2

Table 42-1Acute Kidney Injury Definitions Using RIFLE, pRIFLE, and AKIN

Definition of AKI in Neonates and Infants

There are additional important factors to consider in defining AKI in neonates using serum Cr and urine output criteria. First, neonatal serum Cr following birth reflects maternal Cr, and it decreases to a steady state over 1 to 2 weeks in term infants and over 3 to 4 weeks in preterm infants as the neonate’s GFR steadily improves.3, 4 Tables 42-2 and 42-3 show the increasing GFR in preterm and term neonates.5, 6 Second, unlike in ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.