Recently developed consensus functional definitions on the basis of specific changes in the serum creatinine concentration and urine volume now complement anatomical approaches to diagnosis.
In 2004, the ADQI group and representatives from three nephrology societies established the Acute Kidney Injury Network (AKIN). Its intentions are to facilitate international, interdisciplinary and intersocietal collaborations and to ensure progress in the field of AKI, including the development of uniform standards for the definition and classification of AKI. As part of this process, the RIFLE nomenclature and classification was modified to a staging/classification system differentiating between AKI stage I, II and III. In addition, a 48-hour time window for the diagnosis of AKI was introduced to ensure that the process was acute.
NKF Definition of Chronic Kidney Disease
Kidney damage for three or more months, as defined by structural or functional abnormalities of the kidney, with or without decreased GFR, manifested by pathologic abnormalities or markers of kidney damage, including abnormalities in the composition of the blood or urine or abnormalities in imaging tests
GFR < 60 mL per minute per 1.73 m2 for three months or more, with or without kidney damage