Acute renal failure (ARF) is a rapid loss of renal function resulting in retention of nitrogenous (urea and creatinine)and non nitrogenous waste products. Depending on the severity and duration of the renal dysfunction, this accumulation is accompanied by metabolic disturbances, such as metabolic acidosis and hyperkalaemia, changes in body fluid balance , and effects on many other organ systems. It can be characterised by oliguria (although an- or nonoliguric ARF can occur). It is a serious kidney disease and treated as a medical emergency.

Causes

Renal failure, whether chronic or acute, is usually categorised occording to pre-renal, renal and post-renal causes:

• Pre-renal (causes in the blood supply):
  • Hypotension (decreased blood supply), usually from shock or dehydration and fluid loss
  • Vascular problems, such as renal artery thrombosis
• Renal (damage to the kidney itself):
  • infection
  • toxins or medication (e.g. some NSAIDs, aminoglycoside antibiotics, amphotericin B)
  • rhabdomyolysis (breakdown of muscle tissue; the resultant release of myoglobin in the blood affects the kidney)
  • hemolysis (breakdown of red blood cells, with the hemoglobin damaging the tubules)
  • blunt trauma
• Post-renal (causes in the urinary tract):
  • Urinary retention (as a side-effect of medication or due to benign prostatic hypertrophy)
  • Pyelonephritis

Treatment

Acute renal failure is usually reversible if treated promptly and appropriately. Dialysis may be required temporarily. The kidneys will recover with resumption of adequate renal perfusion with fluid resuscitation. The underlying cause should also be investigated and treated. A proportion of patients will never regain full renal function and require dialysis.

History

Acute renal failure due to acute tubular necrosis (ATN) was recognised in the 1940s in the United Kingdom, where crush victims during the Battle of Britain developed patchy necrosis of renal tubules, leading to a sudden decrease in renal function (Bywaters EG, Beall D. Crush injuries with impairment of renal function. Br Med J 1941;1:427-32). During the Korean and Vietnam wars, the incidence of ARF decreased due to better acute management and intravenous infusion of fluids (Schrier et al, 2004).

References

• Schrier RW, Wang W, Polle B, Mitra A. Acute renal failure: definitions, diagnosis, pathogenesis, and therapy. J Clin Invest 2004;114:5-14. Full text. PMID 15232604.