Continuous renal replacement therapy in acute liver failure

Abstract

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.

Keywords: Acute liver failure; Continuous renal replacement therapy; Hyperammonaemia; Cerebral oedema; Acute liver injury

Core Tip: The early initiation of continuous renal replacement therapy in patients admitted to the intensive care unit with acute liver failure is safe and provides a range of benefits that are likely neuroprotective. These include control of hyperammonaemia, prevention of fever, control of acidaemia, control of fluid balance and control of electrolyte derangement. Continuous renal replacement therapy can be started in all acute liver failure patients intubated for hepatic encephalopathy and should not be delayed until evidence of renal failure becomes apparent.