Structural and functional changes observed in the aging kidney predisp
ose the elderly patient to acute renal failure. Up to 36% of the patie
nts with acute renal failure from this institution were over 70 yr, an
d the literature is full of similar experiences, The elderly patient w
ith abrupt cessation of adequate renal function requires a special wor
k-up in diagnosis and treatment, Prerenal and obstructive causes are o
f particular interest. Although the question of whether or not age has
an independent prognostic importance during an episode of acute renal
failure remains debated; when these and other authors compared the ou
tcome of young and old populations with these disorders, a similar evo
lution was always observed. Age should not be used as a discriminant f
actor in therapeutic decisions concerning acute renal failure.