Liver Failure

Question 1

Define

Answer 1

• Definition: severe liver dysfunction leading to jaundice, encephalopthy and coagulopathy
• It is classified based on the time interval between the onset of jaundice and the development of hepatic encephalopathy

Hyperacute = < 7 days

Acute = 1-4 weeks

Subacute = 4-12 weeks

• Acute-on-Chronic Liver Failure = acute deterioration (decompensation) in patients with chronic liver disease

Question 2

Causes

Answer 2

Viral

• Hepatitis A, B, C, D and E

Drugs

• Paracetamol overdose
• Idiosyncratic drug reactions

Less common causes

• Autoimmune hepatitis
• Budd-Chiari syndrome
• Pregnancy-related
• Malignancy (e.g. lymphoma)
• Haemochromatosis
• Mushroom poisoning (Amanita phalloides)
• Wilson’s disease

Pathogenesis of the manifestations of liver failure

• Jaundice - due to decreased secretion of conjugated bilirubin
• 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
• Coagulopathy
  
  • Reduced synthesis of clotting factors
  • Reduced platelets
  • Platelet functional abnormalities associated with jaundice or renal failure

Question 3

Epidemiology

Answer 3

Paracetamol overdose counts for 50% of acute liver failure in the UK

Question 4

Symptoms

Answer 4

May be asymptomatic

Fever

Nausea

Jaundice (not always)

Question 5

Signs

Answer 5

• 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

Question 6

Investigations

Answer 6

Identify the cause

• Viral serology
• Paracetamol levels
• Autoantibodies (e.g. ASM, Anti-LKM)
• Ferritin (haemochromatosis)
• Caeruloplasmin and urinary copper (Wilson’s disease)

Bloods

• FBC
  
  • Low Hb (if GI bleed)
  • High WCC (if infection)
• U&Es
  
  • May show renal failure (hepatorenal syndrome)
• Glucose
• LFTs
  
  • High bilirubin
  • High AST, ALT, ALP, GGT
  • Low albumin
• ESR/CRP
• Coagulation screen
• ABG - to determine blood pH
• Group and save

Liver US/CT

Ascitic Tap

• Send for MC&S
• If neutrophils > 250/mm3 = spontaneous bacterial peritonitis

Doppler scan of hepatic or portal veins - check for Budd-Chiari syndrome

EEG - monitor encephalopathy

Question 7

Managemetnt

Answer 7

• Resuscitation - ABC
• Treat the cause if possible:
  
  • N-acetylcysteine - treatment for paracetamol overdose
• Treatment/prevention of complications (invasive ventilation and cardiovascular support is often required)
  
  • Monitor - vital signs, PT, pH, creatinine, urine output, encephalopathy
  • Manage encephalopathy: lactulose and phosphate enemas
  • Antibiotic and antifungal prophylaxis
  • Hypoglycaemia treatment
  • Coagulopathy treatment - IV vitamin K, FFP, platelet infusions
  • Gastric mucosa protection - PPIs or sucralfate
  • AVOID sedatives or drugs metabolised by the liver
  • Cerebral oedema - decrease ICP with mannitol

Renal Failure

• Haemodialysis
• Nutritional support

Surgical - liver transplant

Question 8

Complications

Answer 8

Infection

Coagulopathy

Hypoglycaemia

Disturbance of electrolyte balance and acid-base balance

Disturbance of cardiovascular system

Hepatorenal syndrome

Cerebral oedema (causing raised ICP)

Respiratory failure

Question 9

Prognosis

Answer 9

Depends on severity and aetiology