Adequacy of haemodialysis and or haemofiltration treatments for patients with acute kidney injury.

Traditionally, the dose of haemodialysis or haemofiltration delivered to patients with kidney failure is assessed by urea clearance. For patients with chronic kidney disease below a critical urea clearance threshold, patient wellbeing is compromised. It was suggested, therefore, that the dose of dialysis or haemofiltration delivered could also affect outcomes for patients with acute kidney injury. Two major prospective multicentre clinical trials have recently reported that a higher intensity of renal support, by either intermittent haemodialysis or continuous renal replacement therapy, did not improve patient survival or recovery from dialysis. It must be recognised, however, that urea clearance is only one component of renal supportive therapy, and other aspects, including volume control, electrolyte homeostasis and acid-base balance, may be equally important targets for patients with acute kidney injury.