Acute liver failure in children is the development of massive hepatic necrosis with subsequent loss of liver function, with or without hepatic encephalopathy. The disease is uncommon, but has a high mortality. Most of the cases in childhood are attributed to paracetamol over dosage, non-A to G viral hepatitis and metabolic conditions. The child may present within hours or weeks with jaundice, encephalopathy, coagulopathy, hypoglycaemia and electrolyte disturbance. Early signs of encephalopathy include alternate periods of irritability and confusion with drowsiness. Older children may be aggressive and unusually difficult. Complications include cerebral oedema, haemorrhage from gastritis or coagulopathy, sepsis and pancreatitis.
Bilirubin may be normal in the early stages, particularly with metabolic disease. Transaminases are greatly elevated (10–100 times normal), alkaline phosphatase is increased, coagulation is very abnormal and plasma ammonia is elevated. It is essential to monitor the acid– base balance, blood glucose and coagulation times. An EEG will show acute hepatic encephalopathy and a CT scan may demonstrate cerebral oedema.
- Maintaining the blood glucose (>4 mmol/L) with intravenous dextrose
- Preventing sepsis with broad-spectrum antibiotics and antifungals
- Preventing haemorrhage, particularly from the gastrointestinal tract with intravenous vitamin K, fresh frozen plasma or cryoprecipitate and H2-blocking drugs or proton pump inhibitors (PPIs)
- Treating cerebral oedema by fluid restriction and mannitol diuresis
- Urgent transfer to a specialist liver unit.
Features suggestive of a poor prognosis are a shrinking liver, rising bilirubin with falling transaminases, a worsening coagulopathy or progression to coma. Without liver transplantation, 70% of children who progress to coma will die.