Liver Failure Flashcards
what is acute liver failure?
liver failure occuring in <26 weeks in a patient with a previously healthy liver
what is the onset duration in hyperacute liver failure?
<= 7 days
what is the onset duration in acute liver failure?
8-21 days
what is the onset duration in subacute liver failure?
4-26 weeks
what is chronic liver failure?
liver failure on a background of cirrhosis
what are the causes of liver failure?
- infection
- drugs
- toxins
- vascular (budd-chiari syndrome)
- primary biliary cirrhosis
- haemochromatosis
- wilson’s disease
- autoimmune hepatitis
- alpha-1 antitrypsin deficiency
- non-alcoholic fatty liver disease
- fatty liver of pregnancy
- malignancy
- HELLP syndrome
what infections can cause liver failure?
- hepatitis A, B and E
- yellow fever
- leptospirosis
what drugs can cause liver failure?
- paracetamol overdose
- halothane
- isoniazid
- MDMA
- alcohol
what toxins can cause liver failure?
- amanita phalloides mushroom
- carbon tetrachloride
what are the clinical features of liver failure?
- hepatic encephalopathy
- abnormal bleeding
- ascites
- jaundice
what does the presences of liver failure and chronic liver disease indicate?
de-compensation of chronic liver disease
what symptom can be seen in fulminant hepatic failure?
raised ICP due to severe cerebral oedema
rapid disease with high mortality rate
what is the pathophysiology of hepatic encephalopathy?
- ammonia accumulates in the circulation
- crosses the blood-brain barrier
- detoxified by astrocytes which form glutamine through the amidation of glutamate
- excess glutamine disrupts the osmotic balance
- astrocytes begin to swell
- cerebral oedema
what are the 4 stages of hepatic encephalopathy?
- altered mood and behaviour, disturbance of sleep pattern, dyspraxia
- drowsiness, confusion, slurring of speech and personality change
- incoherency, restlessness, asterixis
- coma
what is asterixis?
hepatic flap
why are liver function tests checked in liver failure?
- albumin - to check liver enzymes
- bilirubin levels
- assess synthetic function of the liver
why is INR checked in liver failure?
- look for coagulopathy
- establish a diagnosis of liver failure
why are FBCs checked in liver failure?
- leucocytosis (possible infective cause)
- thrombocytopaenia (in chronic liver disease)
- anaemia
why are U&Es checked in liver failure?
- establish baseline renal function
- look for hepato-renal syndrome
- look for electrolyte abnormalities (e.g. hypokalaemia can worsen encephalopathy)
what specific blood tests are performed to establish a cause?
- paracetamol level
- hepatitis
- epstein-barr virus
- cytomegalovirus serology (viral infection)
- alpha-1 anti-trypsin
- caeruloplasmin level (wilson’s disease)
- iron studies (hereditary haemochromatosis)
- auto-antibodies (autoimmune hepatitis, primary biliary cirrhosis, primary sclerosisng cholangitis)
what test can be done to check for haematochromatosis?
iron studies
high ferritin
what test can be done to check for alpha-1 antitrypsin deficiency?
- alpha-1 antitrypsin levels
- spirometry
what test can be done to check for wilson’s disease?
caeruloplasmin level
what complications can arise due to liver failure?
- infection
- cerebral oedema +/- raised ICP
- bleeding
- hypoglycaemia
- multi-organ failure
