Fulminant (Acute) Hepatic Failure

Question 1

What is acute liver disease?

Answer 1

Rapid development of hepatic dysfunction, without prior liver disease, with 6 months being the cut-off

Question 2

What is hepatic encephalopathy?

Answer 2

Decline in brain function due to a build-up of toxic/waste products in the blood, which should be cleared by the liver

Question 3

Signs of hepatic encephalopathy?

Answer 3

Confusion

Liver flap

Question 4

How many vessels attach to the liver and what are they?

Answer 4

1 hepatic artery
1 hepatic portal vein
3 hepatic veins

Question 5

List the different LFTs and how they are affected by acute liver failure?

Answer 5

ALT/AST (alanine transaminase and aspartate transaminase) are raised

Alkaline phosphatase (ALP) is raised

Gamma Glutamyl Transpeptidase (GGT)

Bilirubin

Question 6

What are the “true” liver function tests and how they are affected in acute liver failure?

Answer 6

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

Question 7

What is Wilson’s disease?

Answer 7

Inherited disorder of biliary copper excretion with too much copper being in the liver and NCS; may be a cause in young people

Question 8

Clinical features of acute liver failure?

Answer 8

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

Question 9

Viral causes of acute liver failure?

Answer 9

Hep A, B, C, D, E

CMV (cytomegalovirus)

Epstein-Barr Virus (EBV)

Toxoplasmosis (due to a parasite)

Question 10

What are some other causes of acute liver failure?

Answer 10

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

Question 11

Rare causes of acute liver failure?

Answer 11

Budd Chiari (occlusion of the hepatic veins)
AFLP (Acute Fatty Liver of Pregnancy)
Cholestasis of pregnancy (causes itching)

Question 12

4 general factors for liver damage and examples of each?

Answer 12

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

Question 13

What must the DH include?

Answer 13

All drugs, inc. over the counter, herbal and food supplements

Question 14

Ix for acute liver disease?

Answer 14

LFTs (inc. albumin and bilirubin)
Prothrombin time

Ultra-sound, inc. vascular

Virology

Ix for chronic liver disease

Rarely, a liver biopsy is required

Question 15

Treatment of acute liver disease?

Answer 15

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

Question 16

Dietary considerations?

Answer 16

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

Question 17

What is often supplemented?

Answer 17

Monitor and supplement K, PO4 and Mg

Question 18

Why is hypoglycaemia a sign of acute liver disease?

Answer 18

Liver is unable to mobilise glycogen and gluconeogenesis is impaired

Careful monitoring, as this is a very serious clinical sign

Question 19

How long does it take for an effect to occur on the liver, once a drug has been taken?

Answer 19

6 weeks exposure to effect; often, there will have been something wrong with the liver initially

This can occur with any drug

Question 20

Paracetamol toxicity mechanism?

Answer 20

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

Question 21

Drugs that are known to cause acute liver disease?

Answer 21

Antibiotics:
Co-amoxiclav
Flucloxacillin
NSAID

Statins - rare

Paracetamol

Steroids in weight loss tablets

Question 22

What is fulminant hepatic failure?

Answer 22

Acute liver failure + encephalopathy and prolonged coagulation

Thus, it is acute liver failure with severe impairment of liver and brain function

Question 23

Common causes of FHF?

Answer 23

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

Question 24

Rare causes of FHF?

Answer 24

AFLP (Acute fatty liver of pregnancy)
Mushrooms
Malignancy
Wilson's disease
Budd Chiari
HAV

Question 25

Complications of FHF?

Answer 25

Encephalopathy

Hypoglycaemia
Coagulopathy

Circulatory failure
Renal failure

Infection

Question 26

Treatment of FHF?

Answer 26

Supportive with:
Inotropes and fluids
Renal replacement
Management of raised ICP (intercranial pressure)

Question 27

Definitive treatment for FHF?

Answer 27

Transplantation with lifelong immunosuppression

Question 28

Requirements for super-urgent acute liver failure due to paracetamol?

Answer 28

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

Question 29

Requirements for super-urgent acute liver failure for non-paracetamol causes?

Answer 29

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