Skip to Main Content




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 Graphic Jump Location
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 critically ill adults or children, critically ill neonates may not have their serum Cr measured daily due to the concern for blood loss, and AKI may go unrecognized.7 Elevated bilirubin levels can interfere with the Jaffe reaction assay, a common laboratory method used to measure serum Cr, and lead to an underestimation in the serum Cr if the laboratory does not correct for the ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPediatrics Full Site: One-Year Subscription

Connect to the full suite of AccessPediatrics content and resources including 20+ textbooks such as Rudolph’s Pediatrics and The Pediatric Practice series, high-quality procedural videos, images, and animations, interactive board review, an integrated pediatric drug database, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPediatrics

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

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