Acute renal failure in critically ill patients: indications for and choice of extracorporeal treatment.

The prescription of extracorporeal therapy for patients with acute renal failure involves many options: dialysis sessions may be intermittent or continuous, semicontinuous or slow-extended, with controversial indications still to be defined also depending on technical and logistic issues and related to the multidisciplinary cooperation needed in the management of critically ill patients. All efforts to evaluate extracorporeal treatments in these patients must be targeted not only towards supporting renal function, but towards all functional and metabolic derangements that can result from artificial blood purification, in any way achievable.