Agitation in patients with fulminant liver failure is often associated with cerebral oedema. An ammonia > 150 μmol/L indicates a high risk of cerebral oedema and ammonia > 200 μmol/L indicates a high risk of cerebral herniation
The use of benzodiazepines and anti-psychotics (i.e. haloperidol) to control agitation is not advocated in this case. There use may worsen an intracranial hypertension leading to morbidity or mortality.
Therefore this patient (agitated and ammonia 170 μmol/L) should immediately be intubated and undergo neuroprotective ventilation. PaC02 4.5 -5kPa, PaO2 10-12kPa, ETT taped, MAP > 70 mmHg or > 80 mmHg if concerns around intracranial hypertension (which seems likely in this case)
