Acute kidney injury: definition, epidemiology, and outcome.

PURPOSE OF REVIEW: Acute kidney injury (AKI) is a common clinical syndrome whose definition has standardized as a result of consensus by leading experts around the world. As a result of these definitions, reported AKI incidences can now be compared across different populations and settings. Evidence from population-based studies suggests that AKI is nearly as common as myocardial infarction, at least in the western world. This review aims to highlight the recent advances in AKI epidemiology as well as to suggest future directions for prevention and management.

RECENT FINDINGS: This review will focus on the recent studies exploring the AKI epidemiology in and outside the ICU. In particular, the risk of AKI in less severe sepsis is notable as is evidence linking AKI to chronic kidney disease. New emphasis on renal recovery is shaping current thinking as is the use and utility of new biomarkers.

SUMMARY: This article reviews the recent information about the definition, classification, and epidemiology of AKI. Although new biomarkers are being developed, the 'tried and true' markers of serum creatinine and urine output, disciplined by current criteria, will be important components in the definition and classification of AKI for some time to come.