Definition and staging criteria of acute kidney injury in adults
- Paul M Palevsky, MD
Paul M Palevsky, MD
- Section Editor — Renal Failure
- Professor of Medicine
- University of Pittsburgh
- VA Pittsburgh Healthcare System
Acute kidney injury (AKI) refers to an abrupt decrease in kidney function, resulting in the retention of urea and other nitrogenous waste products and in the dysregulation of extracellular volume and electrolytes. The term AKI has largely replaced acute renal failure (ARF), reflecting the recognition that smaller decrements in kidney function that do not result in overt organ failure are of substantial clinical relevance and are associated with increased morbidity and mortality.
Several consensus definitions of AKI have been developed in order to provide a uniform definition of AKI. These definitions are based exclusively on the serum creatinine and urine output and are used primarily to identify patients with AKI in epidemiologic and outcome studies. They are of limited utility in the clinical assessment and management of patients with AKI.
The potential etiologies, diagnosis, and management of AKI are discussed elsewhere. (See "Etiology and diagnosis of prerenal disease and acute tubular necrosis in acute kidney injury in adults" and "Diagnostic approach to adult patients with subacute kidney injury in an outpatient setting" and "Overview of the management of acute kidney injury (acute renal failure)".)
The definition for AKI used in clinical and epidemiologic studies is based on specific criteria that have been sequentially developed. The Kidney Disease: Improving Global Outcomes (KDIGO) definition and staging system is the most recent and preferred definition . Other criteria include the RIFLE criteria  and a subsequent modification proposed by the Acute Kidney Injury Network (AKIN) and others [3-5]. These criteria are outlined in the table (table 1).
The KDIGO guidelines define AKI as follows :To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
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