title: The definition of acute kidney injury and its use in practice.
abstract: Acute kidney injury (AKI) is a common syndrome that is independently associated with increased mortality. A standardized definition is important to facilitate clinical care and research. The definition of AKI has evolved rapidly since 2004, with the introduction of the Risk, Injury, Failure, Loss, and End-stage renal disease (RIFLE), AKI Network (AKIN), and Kidney Disease Improving Global Outcomes (KDIGO) classifications. RIFLE was modified for pediatric use (pRIFLE). They were developed using both evidence and consensus. Small rises in serum creatinine are independently associated with increased mortality, and hence are incorporated into the current definition of AKI. The recent definition from the international KDIGO guideline merged RIFLE and AKIN. Systematic review has found that these definitions do not differ significantly in their performance. Health-care staff caring for children or adults should use standard criteria for AKI, such as the pRIFLE or KDIGO definitions, respectively. These efforts to standardize AKI definition are a substantial advance, although areas of uncertainty remain. The new definitions have enabled the use of electronic alerts to warn clinicians of possible AKI. Novel biomarkers may further refine the definition of AKI, but their use will need to produce tangible improvements in outcomes and cost effectiveness. Further developments in AKI definitions should be informed by research into their practical application across health-care providers. This review will discuss the definition of AKI and its use in practice for clinicians and laboratory scientists.
authors.affiliation: Department of Renal Medicine, Birmingham Heartlands Hospital, Birmingham, UK.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Thomas
authors.affiliation: National Clinical Guideline Centre, London, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Blaine
authors.affiliation: Department of Clinical Biochemistry, University College London Hospitals, London, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Dawnay
authors.affiliation: Nottingham Renal and Transplant Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: Mark A J
authors.initials: MA
authors.lastname: Devonald
authors.affiliation: National Clinical Guideline Centre, London, UK.
authors.forename: Saoussen
authors.initials: S
authors.lastname: Ftouh
authors.affiliation: University College London Centre for Nephrology, Royal Free Hospital, London, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Laing
authors.affiliation: National Clinical Guideline Centre, London, UK.
authors.forename: Susan
authors.initials: S
authors.lastname: Latchem
authors.affiliation: Department of Nephrology, Leeds Teaching Hospitals, Leeds, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lewington
authors.affiliation: Department of Nephrology, Birmingham Children's Hospital, Birmingham, UK.
authors.forename: David V
authors.initials: DV
authors.lastname: Milford
authors.affiliation: Departments of Nephrology and Critical Care, Guy's & St Thomas' Hospital, London, UK.
authors.forename: Marlies
authors.initials: M
authors.lastname: Ostermann
mesh_terms: D058186:Acute Kidney Injury / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007677:Kidney Function Tests; D009626:Terminology as Topic