Hepatology: Liver failure, cirrhosis Flashcards
When is liver failure acute (hyperacute, acute and subacute)?
If onset of symptoms is in < 26 weeks in a patient with a previously healthy liver
1) Hyperacute = 7 days or less
2) Acute = 8-21 days
3) Subacute = 4-26 weeks
What is chronic liver failure?
Onset of liver failure on a background of cirrhosis
Which infections can cause liver failure?
1) Hepatitis A, B & E
2) CMV
3) Yellow fever
4) Leptospirosis
Which drugs can cause liver failure?
1) Paracetamol overdose
2) Halothane
3) Isoniazid
4) MDMA
5) Alcohol
Which two toxins can cause liver failure?
1) Amanita phalloides mushroom
2) Carbon tetrachloride
What are hepatic causes of liver failure?
1) Primary biliary cirrhosis
2) Non-alcoholic fatty liver disease
3) Autoimmune hepatitis
4) Malignancy
What are two pregnancy-related causes of liver failure?
1) Fatty liver of pregnancy
2) HELLP syndrome
What is a vascular cause of liver failure?
Budd-Chiari syndrome
What are genetic causes of liver failure?
1) Haemochromatosis
2) Wilson’s disease
3) Alpha-1 antitrypsin deficiency
What are the clinical features of liver failure?
1) Jaundice
2) Ascites
3) Abnormal bleeding
4) Hepatic encephalopathy
What is a complication of hepatic encephalopathy?
If cerebral oedema is severe, raised ICP may develop - more common in fulminant hepatic failure and has a high mortality rate
What does the presence of signs of both liver failure and chronic liver disease indicate?
A decompensation of chronic liver disease
How does hepatic encephalopathy develop?
1) In liver failure, nitrogenous waste (ammonia) accumulates in the circulation
2) This can cross the BBB and once in cerebral circulation it is detoxified by astrocytes which form glutamine through the amidation of glutamate
3) The excess glutamine disrupts the osmotic balance and the astrocytes begin to swell, giving rise to cerebral oedema
What are the four stages of hepatic encephalopathy?
1) Altered mood and behaviour, disturbance of sleep pattern and dyspraxia
2) Drowsiness, confusion, slurring of speech and personality change
3) Incoherency, restlessness, asterixis
4) Coma
What are you looking for in clinical examination of liver failure?
Signs of encephalopathy and chronic liver disease
What investigations are done in liver failure?
1) Blood tests
2) Peritoneal tap for microscopy and culture
3) Abdominal ultrasound
Which blood tests are done in liver failure?
FBC, U&E, CRP, LFT, albumin, clotting screen (INR)
When is a peritoneal tap done in liver failure?
If there is ascites - to look for spontaneous bacterial peritonitis
Why is an INR done in liver failure?
To look for coagulopathy and establish a diagnosis of liver failure
What are you looking for in a FBC in liver failure?
1) Leucocytosis - possible infective cause
2) Thrombocytopenia - in chronic liver disease
3) Anaemia - normocytic could indicate haemolytic anaemia as in Wilson’s or a GI bleed from oesophageal varices, macrocytic could indicate B12 and folate deficiency as in alcohol excess
Why are U&Es done in liver failure?
1) To establish baseline renal function
2) To look for hepato-renal syndrome
3) To look for any electrolyte abnormalities e.g. hypokalaemia which can worsen encephalopathy and should be corrected
What other blood tests can be done in liver failure to determine the cause?
1) Paracetamol level
2) Hepatitis
3) EBV
4) CMV serology
5) Iron studies (haemochromatosis)
6) α-1 anti-trypsin
7) Caeruloplasmin level (Wilson’s disease)
8) Auto-antibodies (autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis)
What is the most common complication of acute liver failure?
Infection - bacterial infection occurs in up to 80% of patients, fungal infection in 30%
Why does infection occur as a complication of acute liver failure?
Decrease phagocyte action, reduced complement levels and multiple invasive medical interventions
How do patients with infection as a complication of acute liver failure present?
Often atypically with no fever or raised WCC
What are other complications of acute liver failure?
1) Cerebral oedema ± raised ICP
2) Bleeding (where there is a source e.g. introduction of ICP monitors)
3) Hypoglycaemia (easily treated with glucose)
4) Multi-organ failure
What are major complications of cirrhosis?
1) Ascites
2) Spontaneous bacterial peritonitis
3) Hepatic encephalopathy
4) Portal hypertension
5) Variceal bleeding
6) Hepatorenal syndrome
How is liver failure managed?
1) Treat the underlying cause if possible
2) Monitor observations closely including blood glucose
3) Liver transplantation may be necessary
How is hepatic encephalopathy managed?
1) Lactulose - to help nitrogenous waste loss through the bowels, reducing encephalopathy
2) IV mannitol (osmotic diuretic) - to reduce cerebral oedema
How is coagulopathy in liver failure treated?
1) Vitamin K - helps production of coagulation factors
2) Fresh frozen plasma - if patient is bleeding
How is spontaneous bacterial peritonitis managed?
1) Broad spectrum antibiotics
2) Prophylactic ciprofloxacin if high risk e.g. previous episodes, low albumin, high INR and low ascitic albumin
How is renal dysfunction in liver failure treated?
1) May require haemofiltration
2) If patient required fluid resuscitation, human albumin solution rather than crystalloid fluid
What are the KCH criteria for liver transplant?
They are designed to predict poor outcome in acute liver failure and are an indication of patients that should be considered for urgent liver transplantation
What are the KCH criteria for liver transplant for paracetamol induced liver failure?
1) Arterial pH < 7.3 24h after ingestion OR
2) Pro-thrombin time > 100s AND creatinine > 300 µmol/L AND grade III or IV encephalopathy
What are the KCH criteria for liver transplant for non-paracetamol induced liver failure?
1) Prothrombin time > 100s OR
2) Any three of:
- Drug induced liver failure
- Age < 10 or > 40 years
- 1 week from 1st jaundice to encephalopathy
- Prothrombin time > 50s
- Bilirubin ≥ 300µmol/L
Which drug can be used in patients with ascites to aid with offloading the additional fluid?
Spironolactone
