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!


Acute renal failure (ARF) is the sudden decline in renal function resulting in increase in metabolic waste products in the blood and dysregulation of extracellular electrolytes and volumes. This is usually marked by elevations in serum creatinine and increased, normal, or decreased urine output. The terms polyuria, oliguria, and anuria sometimes are used to characterize the type of failure. The term acute kidney injury (AKI) has replaced acute renal failure in the literature in an effort to better characterize the spectrum of impairment in renal function before complete failure.

In order to better characterize the spectrum of acute kidney injury or renal failure, two classification systems were developed to standardize assessment of acute kidney injury for clinical and research purposes. Both use creatinine and urine output criteria to stratify renal injury (Table 110-1). The AKIN criteria were developed by the Acute Kidney Injury Network and consist of three stages. AKIN classification has not been validated in children and does not capture milder cases of acute renal injury.1 The other system, called pRIFLE, was developed by modifying existing adult RIFLE criteria. pRIFLE consists of categories of increasing severity: Risk, Injury, Failure, Loss, and End Stage Renal Disease.2,3

TABLE 110-1*Criteria for Diagnosis of Acute Kidney Injury

Traditionally, elevated serum creatinine is used to make the diagnosis of renal failure. This is problematic for several reasons. Serum creatinine is an isolated measurement and does not accurately reflect ongoing changes in renal function. Creatinine takes time to accumulate ...

Pop-up div Successfully Displayed

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