Treatment
Those with severe encephalopathy (stages 3 and 4) are at risk of obstructing their airway due to decreased protective reflexes such as the gag reflex. This can lead to respiratory arrest. Transferring the person to a higher level of nursing care, such as an intensive care unit, is required, and intubation of the airway is often necessary to prevent life-threatening complications (e.g., aspiration or respiratory failure). Placement of a nasogastric tube permits the safe administration of nutrients and medication.The treatment of hepatic encephalopathy depends on the suspected underlying cause (types A, B, or C) and the presence or absence of underlying causes. If encephalopathy develops in acute liver failure (type A), even in a mild form (grade 1–2), it indicates that a liver transplant may be required, and transfer to a specialist centre is advised. Hepatic encephalopathy type B may arise in those who have undergone a TIPS procedure; in most cases this resolves spontaneously or with the medical treatments discussed below, but in a small proportion of about 5%, occlusion of the shunt is required to address the symptoms.In hepatic encephalopathy type C, the identification and treatment of alternative or underlying causes is central to the initial management. Given the frequency of infection as the underlying cause, antibiotics are often administered empirically (without knowledge of the exact source and nature of the infection). Once an episode of encephalopathy has been effectively treated, a decision may need to be made on whether to prepare for a liver transplant.
Diagnosis
Investigations
The diagnosis of hepatic encephalopathy can only be made in the presence of confirmed liver disease (types A and C) or a portosystemic shunt (type B), as its symptoms are similar to those encountered in other encephalopathies. To make the distinction, abnormal liver function tests and/or ultrasound suggesting liver disease are required, and ideally a liver biopsy. The symptoms of hepatic encephalopathy may also arise from other conditions, such as bleeding in the brain and seizures (both of which are more common in chronic liver disease). A CT scan of the brain may be required to exclude bleeding in the brain, and if seizure activity is suspected an electroencephalograph (EEG) study may be performed. Rarer mimics of encephalopathy are meningitis, encephalitis, Wernickes encephalopathy and Wilsons disease; these may be suspected on clinical grounds and confirmed with investigations.The diagnosis of hepatic encephalopathy is a clinical one, once other causes for confusion or coma have been excluded; no test fully diagnoses or excludes it. Serum ammonia levels are elevated in 90% of people, but not all hyperammonaemia (high ammonia levels in the blood) is associated with encephalopathy. A CT scan of the brain usually shows no abnormality except in stage IV encephalopathy, when brain swelling (cerebral oedema) may be visible. Other neuroimaging modalities, such as magnetic resonance imaging (MRI), are not currently regarded as useful, although they may show abnormalities.