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
what are the complications of cirrhosis?
- ascites
- spontaneous bacterial peritonitis
- hepatic encephalopathy
- portal hypertension
- variceal bleeding
- hepatorenal syndrome
what investigation should be carried out if ascites is present?
peritoneal tap should be taken for microscopy and culture to look for spontaneous bacterial peritonitis
how is spontaenous bacterial peritonitis confirmed?
tap and neutrophil count >250 cells/mm3
how do you manage encephalopathy?
oral lactulose
helps nitrogenous waste loss through bowels (reducing encephalopathy)
how is coagulopathy managed?
- vitamin K
- fresh frozen plasma can be given if patient is bleeding
how is spontaneous bacterial peritonitis managed?
broad spectrum antibiotics
ceftriaxone, cefotazime or ciprofloxacin
how is renal dysfunction managed?
- may require haemofiltration
- if requiring fluid resuscitation -> human albumin solution rather than crystalloid fluid
what criteria is used to assess liver transplantation?
king’s college hospital criteria
what is king’s college hospital criteria for liver transplant in paracetamol induced failure?
arterial pH <7.3 24hrs AFTER ingestion
OR
* prothrombin time >100s
* AND creatinine >300 umol/L
* AND grade III or IV encephalopathy
what is king’s college hospital criteria for liver transplant in non-paracetamol induced failure?
prothrombin time >100s
OR any three of:
* drug-induced liver failure
* age <10 or >40
* 1 week from 1st jaundice to encephalopathy
* prothrombin time >50s
* bilirubin >=300 umol/L
what is used to treat paracetamol overdose?
N-acetyl cysteine
what medication is used to reduce the risk of recurrence of overt hepatic encephalopathy?
rifaximin
antibiotic that reduces intestinal production and absorption of ammonia
how does infection secondary to liver failure present?
- fever and raised WBC absent in 30% of patients
how does budd-chiari present?
- acute or sub-acute liver failure
- abdominal pain
- ascites
- hepatomegaly
what is hereditary haemochromatosis?
genetic condition of increased intestinal iron absorption that results in :
* joint pains (2nd and 3rd MCP joints)
* erectile dysfunction
* slate-grey skin pigmentation
* cirrhosis
* dilated cardiomyopathy
* osteoporosis
what investigation should be carried out in suspected hereditary haemochromatosis?
ferritin level and transferrin saturation
* ferritin >1 mg/L
* transferrin saturation >45%
what is the treatment for hereditary haemochromatosis?
regular venesection
what INR level constitutes coagulopathy?
INR of >1.5
what is budd-chiari syndrome?
obstruction of the hepatic veins (often by thrombosis)
how is budd-chiari diagnosed?
doppler ultrasound of the hepatic veins
