Assessment and Protection of Cerebral Function in Patients with Acute Liver Failure

Hepatic encephalopathy (HE) is a frequent and life-threatening neurological complication of acute liver failure (ALF) encountered in the intensive care unit and remains a major determinant of short-term mortality and long-term neurological outcomes. Increasing evidence indicates that HE in ALF is primarily driven by hyperammonemia, with synergistic contributions from systemic inflammation, cerebral hemodynamic dysregulation, metabolic failure, and osmotic imbalance. These interacting mechanisms promote astrocytic swelling, disruption of the blood-brain barrier, cerebral edema, and intracranial hypertension. In patients with ALF, early recognition of cerebral involvement and systematic exclusion of alternative causes of altered mental status are essential. Given the dynamic and heterogeneous neurological manifestations of HE, reliance on isolated clinical, biochemical, or radiological parameters is insufficient. Multimodal neuromonitoring-integrating neurological examination, ammonia kinetics, cerebral hemodynamic assessment, and neuroimaging-allows more accurate assessment of cerebral injury and supports timely, targeted intervention. This review summarizes current evidence on the pathophysiology of HE in ALF with a focus on mechanisms relevant to intensive care practice. We highlight evidence-based strategies for cerebral protection, including early and sustained control of hyperammonemia with continuous renal replacement therapy, optimization of cerebral perfusion and osmotic balance, selective use of plasma exchange, and structured neurocritical care. An integrated management framework is proposed to guide prognostication and inform timely decisions regarding advanced liver support and liver transplantation in the ICU setting.