Acute Liver Failure Flashcards
What is the weight of the liver ?
It makes up about 2.5% of the body weight
Function of the liver ?
- Bile formation
- Cholesterol & lipoprotein metabolism
- Drug metabolism
- Carbohydrate metabolism
- Fatty acid metabolism
- Ammonia metabolism
- Storage; A,B12,D,glycogen, iron
- Immunology
Characteristics of ALF?
- INR > 1.5
- Hepatic encephalopathy
- Vasoplegic CVS collapse
Classification of liver failure?
- Hyperacute
- Acute
- Subacute
What is hyperacute liver failure ?
This is where encephalopathy occurs within 7 days of jaundice
What is acute liver failure ?
This has an interval of between 8 - 28 days from jaundice to encephalopathy
What is subacute liver failure?
This is when encephalopathy occurs between 28 days - 12 weeks after the onset of Jaundice
What is the most common precipitant of infective ALF?
Hepatitis A,B & E
Risk of ALF is lowest with Hepatitis A
Transplant in secondary liver failure?
Not an option but is only indicated in patients with primary liver failure
Infective causes of ALF?
- Hepatitis - A,B,E & seronegative hepatitis
- HSV, CMV
- Chicken-pox (Immuno-compromised)
Does hepatitis C cause ALF?
This is not a common cause
Hepatitis D infection in ALF?
Hepatitis D requires Hepatitis B co-infection
What are the causes of drug related ALF?
- Acetaminophen
- TB drugs
- MDMA, Cocaine
- Idiosyncratic reactions ( Anticonvulsants, Abx, NSAIDs)
- Aspirin - In kids lead to Reye’s syndrome
- Kava kava root supplement
What are the causes of toxin related ALF?
- Carbon tetrachloride
- Phosphorous
- Amanita Phalloides
- Alcohol
What are the possible vascular events causing ALF?
- Ischaemia
- Veno-occlusive disease
- Budd-Chiari syndrome (Hepatic vein thrombosis)
- Hyperthermic liver injury
Pregnancy related ALF?
- Acute fatty liver of pregnancy
- HELLP syndrome
- Liver rupture
What is the full meaning of HELLP ?
Haemolysis
Elevated liver enzymes
Low platelets
Other rare causes of ALF?
- Wilson’s disease
- Auto-immune
- Lymphoma
- Carcinoma
- Haemophagocytic syndrome
- Trauma
Metabolism of Acetaminophen and pathways in overdose?
Cytochrome P450 converts 5% of Acetaminophen to N-Acetyl Pbenzoquinoneimine (NAPQI) - This is a metabolite
NAPQI detoxification by hepatic glutathione - Conjugation
Hepatic glutathione becomes depleted in overdose, hence NAPQI persists to cause cellular damage
NAC infusion restores the depleted hepatic glutathione . Very effective within 8-12 hrs
factors potentiating depletion of glutathione stores?
- Anorexia
- Malnutrition
- Chronic alcohol use
- Enzyme inducing drugs (Phenytoin & Carbemazepine)
- Cystic fibrosis
- HIV
List some common enzyme inducers?
- Phenytoin
- Carbemazepine
- Rifampicin
- Phenobarbitone
- Chronic alcohol use
What is the composition of the hepatic portal vein?
- Superior mesenteric vein
- Splenic vein
Also receives blood from;
- Inferior mesenteric
- Gastric veins
- Cystic veins
Characteristics of the hepatic portal vein?
- ## About 75% of liver blood supply
what is Wilson’s disease?
- Inherited autosomal recessive
- Defective coding of copper-transporting ATPase
- Insufficient copper excretion in bile
- Accumulation in brain, liver & cornea
- Diagnosis by measuring serum copper & ceruloplasmin
What is the definition of acute decompensated liver failure ?
- New onset ascitis
- Hepatic encephalopathy
- GI bleeding
- Infection - CLD
Acute on chronic liver failure ?
- Acute decompensation
- Organ failure
What are the components of the CLIF-SOFA score ?
- Liver
- Kidney
- Circulation
- Lungs
- Brain
- Coagulation
What are the common organisms causing infection in chronic liver patients?
- E.Coli
- Staph Aureus
- E. Faecalis
- Strep pneumoniae
- Pseudomonas
- Staph epidermidis
- MRSA
- VRE
- ESBL-Producing enterobacteria
List few familial liver diseases?
- Alpha-1-Antitrypsin deficiency
- Haemochromatosis
- Wilson disease
- Cystic fibrosis
List a few genetic metabolic diseases which could cause liver failure in children?
- Reye’s syndrome
- Gaucher disease
- Niemann-pick disease
- Tangier disease
- Fabry disease
- Hurler
Management of haemochromatosis ?
Venesection to prevent liver failure
Common presenting sigs with ALF?
- Jaundice
- Encephalopathy
- Coagulopathy
Distinguishing between the acuity of liver failure?
Understanding the interval from the onset of jaundice to the development of encephalopathy
Underlying pathologies which could cause acute deterioration in patients with CLD?
- Sepsis
- Dehydration
- Electrolyte abnormalities
- Sedative drugs
- Portal vein thrombosis
- Liver tumor
- GI bleed
Checking bilirubin to determine the extent of hemolysis’s contribution to jaundice ?
- Conjugated
- Unconjugated
Laboratory markers specific for the liver?
- ALT
Interpretation of AST & ALT?
In alcohol related ALF, AST is usually twice that of ALT
Coagulation factors produced by the liver ?
I, II, V, VII, IX & X
Hematological changes in ALF?
- Macrocytic Hypochromic erythrocytes
- Pancytopenia
Chronic low-grade blood loss could be caused by?
Hypertensive gastropathy