Acute renal failure: pathogenesis, diagnosis and conservative treatment

Acute renal failure (ARF) is defined as a rapid, sudden onset deterioration of renal function (glomerular filtration rate, GFR) with the ensuing accumulation of uraemic waste products. Frequently, the impairment of GFR is accompanied by the impossibility to maintain acid-base, electrolyte, and fluid balance; in about 2/3 of cases, patients with ARF will develop oliguria (defined as urine output <500 ml/day). Generally, ARF is a frequent complication, particularly amongst hospitalised patients. In patients requiring treatment in intensive care units, its incidence can be as high as 30%. Moreover, ARF remains to be associated with a high mortality of 50-70%, particularly in patients requiring renal replacement therapy. On the other hand, ARF is typically reversible; less than 5% of survivors will require chronic renal replacement therapy. Thus, the major focus of treating these patients is the prevention of uraemic complications. This can be reached by adequate conservative treatment measures, or, if necessary, by adequate and effective renal replacement therapy with which the time to spontaneous renal recovery must be bridged. In addition to the discussion of treatment standards for established ARF, the present review article will discuss potential strategies for the prevention of ARF in patients at high risk to develop renal failure.