Acute Liver Failure Flashcards
What is acute liver failure?
Clinical manifestation of sudden and severe hepatic injury which leads to encephalopathy , coagulopathy and frequent multi organ failure
What are the essential components of ALF?
Encephalopathy
Coagulopathy (INR more or equal to 1.5)
No pre existing liver disease
Illness <26weeks
What are the 3 presentations of fulminant liver failure?
Hyperacute, acute, subacute
Give the features of Hyperacute fulminant liver failure
Time from jaundice to encephalopathy is 0-1 week
Severity of encephalopathy is +++
Severity of jaundice is +
Degree of intracranial hpt +++
Survival rate without transplant:good
What typically causes hyperacute fulimant liver failure?
- Paracetamol OD
- Hep A and E
- Ischaemic hepatitis
Features of acute fulminant liver failure
Time from jaundice to encephalopathy 1-4 weeks
Severity of coagulopathy ++
Severity of jaundice ++
Degree of intracranial hpt ++
Survival rate without emergency liver transplant is moderate
What causes acute fulminant liver failure
Acute hep B
What are the features of subacute liver failure
Time from jaundice to encephalopathy is 4-12 weeks
Severity of coagulopathy +
Severity of jaundice +++
Degree of intracranial hpt +/-
Survival rate without liver transplant: poor
What causes subacute liver failure
Idiosyncratic, DILI, cryptogenislc
What aetiologies does acute liver failure have?
Viral hepatitis: HAV, HBV, HEV, HSV 1/2, VZV
Drugs and toxins: Paracetamol, tb drugs, arvs, antimicrobials
Pregnancy related liver disease
Ischaemic shock
Acute budd-chiari syndrome
Autoimmune hepatitis
True or false: acute liver failure is caused by only one factor and does not interact with other factors
False, factors like Etiology, other host factors like sex and age, host genetocs and the hepatic environment acts together to cause ALF
What is the 1st step in management of ALF
Early diagnosis + transfer to appropriate care:
INR more or equal to 1.5, altered mental status with no pre existing liver disease needs transfer to hospital
What must you give a patient with early warning signs of cerebral oedema
IVI mannittol prior to transfer and during transfer give IVI dextrose to maintain euglycaemia
What is step 2 of management of ALF
Decision to give N-acetylcysteine if paracaetamol hepatotoxicity is suspected
What is stage 3 of management of ALF
Look for necessity to transfer to liver transplant unit:
INR>2 or grade 2 encephalopathy
High risk patients: <10/>40
Aetiologies with poor prognosis
What is the 4th step in management of alf
Listing for emergency liver transplant using kings college criteria
What are the required factors needed for emergency liver transplant in a suspected Paracetamol induced ALF according to kings criteria
Arterial pH <7.30 after fluid resus
Serum lactate >3.5mmol/l at 4hr or >3mmol/l at 12hr
Or all of the following:
INR>6.5
serum creatinine >300
Grade 3/4 hepatic encephalopathy
What are the requirements for a non-paracaetamol induced alf according to kings college criteria
INR> 6.5
Any grade encephalopathy
OR ANY THREE OF THE FOLLOWING:
Non-A, non-B viral hepatitis, drug induced or intermediate aetiology of ALF
Time from jaundice to hepatic encephalopathy >7days
Age<10/>40
INR>3.5
Serum bili >300
What are complications of ALF
Infection: bacterial or fungal Infections within 3 days
Raised ICP + cerebral oedema:
Risk factors:
Hyperacute>acute>subacute
Serum ammonia>150-200
Clinical correlate of HE grade 3/4
Need for vasopressors or renal replacement therapy
Presence of infection or SIRS
Cardiovascular:
Hyperdynamic circulation
Resp:
Airway compromise leading to resp/metabolic acidosis
Coagulopathy:
Prolonged INR, decreased platelets
Nutrition:
Patients are catabolic
How is HE class one classified?
How is HE class 2 classified
How is HE class 3 classified as
How is HE class 4 classified as
How many grams of protein and calories should a patient eat a day to prevent going to HE grade 3/4
1g protein/kg/day
25-30kcal/kg/day
How does N-acetyl cysteine help prevent ALF
Replenishes glutathione stores and improves systwmic and cerebral haemodynamics
How many IVI NAC must be given
Loading dose of 150mg/kg in 5% dextrose over 15 min
50mg/kg over 4hrs
100mg/kg over 16hrs
True or false: you should wait for paracetamol levels to come back from lab before giving IVI NAC
False dont wait
What quantity of paracetamol is classified as being hepatotoxic
> 10g per day
3-4g/day in setting of chronic alcohol use or malnutrition
True or false: acute alcohol use can be protective of Paracetamol hepatotoxicity
True
What drug should be given immediately when acute herpes simplex hepatitis is suspected
IVI acyclovir 10mg/kg 8 hrly immediately
True or false: only hsv 2 can cause hepatitis
False, both hsv1 and 2 can
Where is HSV hepatitis more frequently found
Immunocomprimised people and pregnancy
What are the clinical symptoms of hsv hepatitis
Fever, headache, anorexia with nausea and vomiting, abdominal pain, leukopenia
What is the emergency treatment for raised ICP and cerebral oedema
IVI 5% dextrose saline drip
IVI 20% mannitol
Where is the fulminant presentation of acute hepatitis B more common
Co-infection with HIV and HBV
What can cause reactivation of HEP B
Chemotherapy or immunosuppression
What do you give a patient with only HB IgM core Ab positive
Lamivudine 150mg
Conversion to tenofovir 300mg daily once clinically stable
What are the 3 interacting factors affecting outcome of emergency liver transplants
Age
Severity of pre transplant illness
Nature and quality of graft
What causes death post transplant
Sepsis
Multi organ failurre
Brainstem herniation
Fulminant liver failure
Classification of hepatic encephalopathy
