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
