[Skip to Content]
[Skip to Content Landing]
May 14, 1982

Acute Renal Failure

JAMA. 1982;247(18):2518-2525. doi:10.1001/jama.1982.03320430028025

Acute Renal Failure Defined  The term acute renal failure can be used for any situation in which the patient's BUN and creatinine levels rise. However, I favor a more restrictive use of the term for situations in which the rise in BUN and creatinine levels are not reversible immediately by altering extrarenal factors.For example, when volume depletion occurs (eg, diarrhea) and the kidney is hypoperfused, there is increased tubular back-diffusion of urea into the circulation, with a resultant rise in BUN level. We use the term prerenal azotemia for this condition. The BUN concentration returns to normal within 24 hours if volume repletion is effected. The BUN level also will rise with bladder-outlet obstruction (eg, prostatic hypertrophy), since the accompanying slower flow of fluid through the renal tubules is also associated with back-diffusion of urea. This situation is termed postrenal azotemia, and a bladder catheter to relieve the obstruction