Continuous renal replacement therapy in acute liver failure.

Acute liver failure (ALF) is a devastating condition that primarily affects young adults. This often-lethal condition involves a rapid loss of hepatic function, that then leads to multiple organ failure. The accumulation of numerous toxins, especially ammonia, causes cerebral oedema and intracranial hypertension. Continuous renal replacement therapy (CRRT) is increasingly recognized as having a key role in ammonia removal in ALF and current evidence suggesting that timing of initiation, dose, and duration of therapy may influence survival. In addition to this important role of toxin clearance, CRRT helps with other complications of ALF such as acid-base balance, prevention of fever and management of fluid balance. As such, we propose that CRRT in ALF should be viewed as an "metabolic-toxin-fluid" therapy as much as a treatment for renal failure. In this review article we will explore the mechanisms of benefit, indications and evidence to support this concept of CRRT in ALF.