Liver Failure Flashcards
Definition
Severe liver dysfunction leading to jaundice, encephalopthy and coagulopathy
Classification
It is classified based on the time interval between the onset of jaundice and the
development of hepatic encephalopathy
o Hyperacute = < 7 days
o Acute = 1-4 weeks
o Subacute = 4-12 weeks
Definition (acute)
Acute-on-Chronic Liver Failure = acute deterioration (decompensation) in patients
with chronic liver disease
Aetiology (common)
• Viral
o Hepatitis A, B, C, D and E
• Drugs
o Paracetamol overdose
o Idiosyncratic drug reactions
Aetiology (less common)
o Autoimmune hepatitis o Budd-Chiari syndrome o Pregnancy-related o Malignancy (e.g. lymphoma) o Haemochromatosis o Mushroom poisoning (Amanita phalloides) o Wilson's disease
Pathogenesis (jaundice)
- due to decreased secretion of conjugated bilirubin
Pathogenesis (encephalopathy)
• Nitrogenous products (e.g. ammonia) is absorbed in the gut and goes via
the portal circulation to the liver
• A normal liver would be able extract these harmful substances
• However, if the liver is failing, these toxic products can go through the liver
and reach the brain and exert its effects
Pathogenesis (coagulopathy)
- Reduced synthesis of clotting factors
- Reduced platelets
- Platelet functional abnormalities associated with jaundice or renal failure
Epidemiology
Paracetamol overdose counts for 50% of acute liver failure in the UK
Presenting symptoms
- May be asymptomatic
- Fever
- Nausea
- Jaundice (not always)
Signs on physical examination
- Jaundice
- Encephalopathy
- Asterixis
- Fetor hepaticus
- Ascites and splenomegaly (less common if acute or hyperacute)
- Bruising or bleeding
- Signs of secondary causes (e.g. bronze skin colour, Kayser-Fleisher rings)
- Pyrexia - may indicate infection or liver necrosis
Investigations (to find cause)
o Viral serology o Paracetamol levels o Autoantibodies (e.g. ASM, Anti-LKM) o Ferritin (haemochromatosis) o Caeruloplasmin and urinary copper (Wilson's disease)
Investigations (bloods)
o FBC
• Low Hb (if GI bleed)
• High WCC (if infection)
o U&Es
• May show renal failure (hepatorenal syndrome)
o Glucose
o LFTs
• High bilirubin
• High AST, ALT, ALP, GGT
• Low albumin
o ESR/CRP
o Coagulation screen
o ABG - to determine blood pH
o Group and save
Investigations (other)
• Liver US/CT
• Ascitic Tap
o Send for MC&S
o If neutrophils > 250/mm3 = spontaneous bacterial peritonitis
- Doppler scan of hepatic or portal veins - check for Budd-Chiari syndrome
- EEG - monitor encephalopathy
Management plan (immediate)
• Resuscitation - ABC
• Treat the cause if possible:
o N-acetylcysteine - treatment for paracetamol overdose
