RENAL SYSTEM: Edited by Marlies OstermannIdentification of acute kidney injury subphenotypesEndre, Zoltan H.a; Mehta, Ravindra L.bAuthor Information aDepartment of Nephrology, Prince of Wales Hospital and Clinical School, University of New South Wales, Sydney, New South Wales, Australia bDivision of Nephrology, Department of Medicine, University of California San Diego, San Diego, California, USA Correspondence to Ravindra L. Mehta, MD, Division of Nephrology, UC San Diego, 9452 Medical Center Drive, La Jolla, CA 92037, USA. Tel: +1 858 246 2134; fax: +1 858 246 2088; e-mail: [email protected] Current Opinion in Critical Care: December 2020 - Volume 26 - Issue 6 - p 519-524 doi: 10.1097/MCC.0000000000000772 Buy Metrics Abstract Purpose of review AKI is a complex clinical syndrome with many causes and there is a broad range of clinical presentations that vary according to duration, severity and context. Established consensus definitions of AKI are nonspecific and limited to kidney function. This reduces treatment options to generic approaches rather than individualized, cause-based strategies that have limited both understanding and management of AKI. Recent findings The context and the temporal phase of kidney injury are critical features in the course of AKI and critical to timing-relevant intervention. These features are missing in generic definitions and terms used to describe AKI. Subphenotypes of AKI can be identified from novel damage biomarkers, from functional changes including creatinine trajectories, from the duration of change and from associated clinical characteristics and comorbidities. Subphenotype parameters can be combined in risk scores, or by association strategies ranging from a simple function-damage matrix to complex methods, such as machine learning. Examples of such strategies are reviewed along with tentative proposals for a revised nomenclature to facilitate description of AKI subphenotypes. Summary Appropriate intervention requires refinement of the nomenclature of AKI to identify subphenotypes that facilitate correctly timed and selectively targeted intervention. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.