Fulminant (Acute) Hepatic Failure Flashcards
What is acute liver disease?
Rapid development of hepatic dysfunction, without prior liver disease, with 6 months being the cut-off
What is hepatic encephalopathy?
Decline in brain function due to a build-up of toxic/waste products in the blood, which should be cleared by the liver
Signs of hepatic encephalopathy?
Confusion
Liver flap
How many vessels attach to the liver and what are they?
1 hepatic artery
1 hepatic portal vein
3 hepatic veins
List the different LFTs and how they are affected by acute liver failure?
ALT/AST (alanine transaminase and aspartate transaminase) are raised
Alkaline phosphatase (ALP) is raised
Gamma Glutamyl Transpeptidase (GGT)
Bilirubin
What are the “true” liver function tests and how they are affected in acute liver failure?
Bilirubin
Albumin - protein made by the liver; this will decrease
Prothrombin (clotting) time - liver is responsible for the production of coagulation factors; this is increased in fulminant hepatic failure
What is Wilson’s disease?
Inherited disorder of biliary copper excretion with too much copper being in the liver and NCS; may be a cause in young people
Clinical features of acute liver failure?
Can be asymptomatic, otherwise they will be:
Jaundice
Malaise and lethargy
Nausea and anorexia
Pain (not common) and arthralgia
Pruritus (itch) due to deposition of bilirubin in fat cells
Hypoglycaemia
ABNORMAL LFTs
Viral causes of acute liver failure?
Hep A, B, C, D, E
CMV (cytomegalovirus)
Epstein-Barr Virus (EBV)
Toxoplasmosis (due to a parasite)
What are some other causes of acute liver failure?
Drugs
Alcohol
Paracetamol injury
Shock liver (ischaemic hepatitis) is causes by insufficient blood flow to the liver (usually due to shock and hypotension - the hepatic veins already have a very low BP)
Malignancy
Chronic liver disease
Rare causes of acute liver failure?
Budd Chiari (occlusion of the hepatic veins)
AFLP (Acute Fatty Liver of Pregnancy)
Cholestasis of pregnancy (causes itching)
4 general factors for liver damage and examples of each?
Direct toxicity, e.g: drugs, alcohol, viruses, hypoperfusion
Nutrition, e.g: NASH and malnutrition
Genetic predisposition, e.g: Wilson’s and haemochromatosis
Immunological, e.g: primary biliary cirrhosis
What must the DH include?
All drugs, inc. over the counter, herbal and food supplements
Ix for acute liver disease?
LFTs (inc. albumin and bilirubin)
Prothrombin time
Ultra-sound, inc. vascular
Virology
Ix for chronic liver disease
Rarely, a liver biopsy is required
Treatment of acute liver disease?
Rest for up to 3 months; recovery may take 6 months
Fluids, NO alcohol
Increase calories, high fat foods poorly tolerated
For itch, sodium bicarbonate bath, cholestryamine or uresodeoxycholic acid can be given
Observation for fulminant hepatic failure
Dietary considerations?
Patients are frequently hypermetabolic, thus energy requirements and protein requirements are raised;
but patients have poor appetite
Additionally, pre-existing malnutrition is common in patients with acute alcoholic hepatitis
There is a higher rate of complications and mortality in malnourished patients; oral nutritional supplements/NG feeding may be required
What is often supplemented?
Monitor and supplement K, PO4 and Mg
Why is hypoglycaemia a sign of acute liver disease?
Liver is unable to mobilise glycogen and gluconeogenesis is impaired
Careful monitoring, as this is a very serious clinical sign
How long does it take for an effect to occur on the liver, once a drug has been taken?
6 weeks exposure to effect; often, there will have been something wrong with the liver initially
This can occur with any drug
Paracetamol toxicity mechanism?
CYP450 metabolises acetaminophen to NAQPI (toxic), which is conjugated to glucothione (the pre-cursor is NAC) and the product is non-toxic
But, glucothione can be depleted and cause paracetamol injury
Drugs that are known to cause acute liver disease?
Antibiotics:
Co-amoxiclav
Flucloxacillin
NSAID
Statins - rare
Paracetamol
Steroids in weight loss tablets
What is fulminant hepatic failure?
Acute liver failure + encephalopathy and prolonged coagulation
Thus, it is acute liver failure with severe impairment of liver and brain function
Common causes of FHF?
Paracetamol
Fulminant viral, e.g: a common one is HBV; sometimes, the hepatitis is non A-E, even if there is a clinical diagnosis of hepatitis
Drugs
Rare causes of FHF?
AFLP (Acute fatty liver of pregnancy) Mushrooms Malignancy Wilson's disease Budd Chiari HAV
Complications of FHF?
Encephalopathy
Hypoglycaemia
Coagulopathy
Circulatory failure
Renal failure
Infection
Treatment of FHF?
Supportive with:
Inotropes and fluids
Renal replacement
Management of raised ICP (intercranial pressure)
Definitive treatment for FHF?
Transplantation with lifelong immunosuppression
Requirements for super-urgent acute liver failure due to paracetamol?
1 pH 55) after resuscitation
2 [PT >100 (INR 6.5)] + [creatinine > 300 or anuria] + [grade 3 or 4 encephalopathy]
3 Lactate > 3.5 (3.0 after resuscitation) > 24h after ingestion
4 Any 2 of 3 from category 2 plus life-threatening deterioration without sepsis
Requirements for super-urgent acute liver failure for non-paracetamol causes?
PT > 100 or INR > 6.5
Any 3 from 5 of unfavourable aetiology (not hep A or B): Age > 40 Jaundice to encephalopathy > 7 days PT > 50 (INR > 3.5) Bilirubin > 300
Wilson’s or Budd-Chiari: any coagulopathy plus encephalopathy
