Acute tubular necrosis

Most acute renal failure is caused by what is loosely termed as acute tubular necrosis; a poorly understood entity which might be summed up as follows:

• a clinical syndrome in specific clinical settings
• acute loss of renal excretory function
• urinary indices suggestive of tubular abnormality:
  • urinary sodium is classically greater than 30 mmol/l, the urea less than 150 mmol/l and the urine plasma osmolality ratio is less than 1:1. Interpretation of the above values is invalidated if loop diuretics or mannitol have been given.
  • red cells and granular casts are generally present. Red cell casts are not associated with this condition and are suggestive of glomerulonephritis.
• recovery is expected over days or weeks; it is not much affected by therapeutic intervention

In fact, the kidney probably recovers by cellular regeneration, which management is unable to speed up; only provide supportive therapy.