Acute liver failure is an uncommon condition whereby serious complications of liver disease rapidly present (within 8 weeks) following the appearance of precipitating illness. This usually occurs in the absence of pre-existing liver disease.
Any cause of liver damage can produce acute liver failure. Causes include:
- Drugs (70-80% of cases): paracetamol overdose, anti-tuberculosis drugs, halothane
- Viral (5%): hepatitis A, hepatitis B
- Acute fatty liver of pregnancy
- Budd-Chiari syndrome
- Liver metastases
Failure occurs when there is insufficient metabolic and synthetic function. It can occur in the absence of pre-existing liver disease (fulminant liver failure) or with pre-existing chronic liver disease.
There are a wide variety of clinical features, although cerebral disturbances are the cardinal manifestation.
- Cerebral disturbance (e.g. hepatic encephalopathy, cerebral oedema). Initiali manifestiations indluce poor concentration, restlessness and drowsiness. Cerebral oedema can lead to neurological signs, including fixed pupils, bradycardia, hyperventilation and focal fits
- Fetor hepaticus
- Ascites and peripheral oedema are late features of acute liver failure
- LFT and GGT: check for raised bilirubin, ALT and ALP
- Clotting studies: prolonged INR and APTT in advanced cirrhosis
- Ferritin: raised in haemochromatosis
- FBC: check for anaemia (gastrointestinal bleeding) and macrocytosis
- U&E: check for hepatorenal syndrome
- Viral serology: hepatitis A-E, EBV, CMV
- Autoantibodies: ANCA, ANA, AMA
- Immunoglobulin levels: IgM, IgG
- Caeruloplasmin: reduced in Wilsons’s disease
- Alpha1-antitrypsin levels
- Ultrasound scan: check liver size, shape and elasticity
- Doppler scan of hepatic veins: check for presence of clots
Patients require urgent transfer to ITU. Monitor and treat complications, which may include cerebral oedema, hypoglycaemia, renal failure, metabolic acidosis and infection. N-acetylcysteine can be used in cases of paracetamol poisoning.
Liver transplants are often required.