For more than 40 years, nephrologists have classified diminished
kidney function as two distinct syndromes — acute and chronic kidney failure.
Whereas chronic kidney disease was recognized in the 19th century, acute
renal dysfunction became evident during the London Blitz of World War II, with the
realization that crush injuries could cause dramatic but often reversible cessation of
renal function. The disease states and stages of both acute and chronic renal syndromes
are delineated according to the serum creatinine concentration or the glomerular
filtration rate (GFR), functional markers that were identified in the early
20th century. Advanced renal impairment in both syndromes is treated with dialysis.
During the past decade, separate conceptual models for chronic kidney disease
and acute kidney injury were developed to facilitate organized approaches to clinical
research and trials. However, recent epidemiologic and mechanistic studies suggest
that the two syndromes are not distinct entities but rather are closely interconnected
— chronic kidney disease is a risk factor for acute kidney injury, acute kidney injury
is a risk factor for the development of chronic kidney disease, and both acute kidney
injury and chronic kidney disease are risk factors for cardiovascular disease