Definition and epidemiology of acute kidney injury

This first paper in a continuous medicine education series on acute kidney injury (AKI) provides recent information on definition, staging and epidemiology of AKI, focusing on resource-limited sub-Saharan countries, including Rwanda.

A first part of the paper discusses the several causes of the AKI syndrome, classified according to their traditional major pathophysiological mechanisms in “prerenal, postrenal and intrarenal, intrinsic AKI”. Some differential diagnostic approaches are provided, emphasizing that all AKI is not acute tubular necrosis.

The history of the modern definitions and classification systems of AKI, starting with RIFLE, AKIN and finally KDIGO is described and the differentiation of acute versus chronic kidney disease is discussed, in particular when a baseline serum creatinine is not available.

Finally, the global epidemiology, and some data, be it incomplete, on epidemiology of AKI in sub- Saharan Africa countries and Rwanda are provided.

Keywords
Acute kidney injury; Definition and classification; Epidemiology; Africa; Rwanda