What are the types of hepatic (liver) failure?

Types of Hepatic Failure

Hepatic failure is classified into three main types: Type A (acute liver failure), Type B (portosystemic bypass/shunting), and Type C (cirrhosis-related), according to the European Association for the Study of the Liver. 1

Type A: Acute Liver Failure (ALF)

• ALF is characterized by the sudden loss of hepatic function in a person without pre-existing liver disease, manifesting with hepatic encephalopathy and coagulopathy 2
• Diagnostic criteria include elevated aminotransferases, cognitive dysfunction, and severe coagulopathy 2
• Common causes include paracetamol overdose, viral hepatitis (A, B, D, E), autoimmune hepatitis, drug-induced liver injury, and ischemic liver injury 2, 3
• The King's College criteria are used for prognostication, with different criteria for paracetamol and non-paracetamol etiologies 4
• Management requires early transfer to an intensive care unit in a center with liver transplant capability 4

Type B: Portosystemic Bypass/Shunting

• This type involves hepatic dysfunction resulting from portosystemic bypass without intrinsic liver disease 1
• It can occur due to congenital or acquired vascular abnormalities that allow blood to bypass the liver 1
• The primary manifestation is often hepatic encephalopathy despite relatively preserved liver function 1

Type C: Cirrhosis-related Liver Failure

• This type occurs in the setting of established cirrhosis and can manifest as:
  • Acute decompensation (AD): hospitalization required for an acute liver-related complication 5
  • Stable decompensated cirrhosis (SDC): patients discharged without readmission during 3-month follow-up 5
  • Unstable decompensated cirrhosis (UDC): patients with liver-related complications requiring readmission but not developing ACLF 5
  • Acute-on-chronic liver failure (ACLF): acute deterioration of liver function in patients with pre-existing chronic liver disease 5, 6

Acute-on-Chronic Liver Failure (ACLF)

• ACLF is a distinct entity with multiple classification systems:

  • EASL-CLIF-C definition: based on organ failure assessment using the CLIF-SOFA score, graded as ACLF-1, ACLF-2, or ACLF-3 based on number of organ failures 5, 6
  • APASL definition: restricted to patients with acute liver dysfunction triggered by acute intrahepatic precipitants; applies to patients with cirrhosis without prior decompensation and those with non-cirrhotic chronic liver disease 5, 6
  • NACSELD definition: captures only the most severe patients receiving organ support 5

• ACLF grading correlates directly with mortality risk 6, 7:

  • ACLF-1: single renal failure or single non-renal organ failure with renal/cerebral dysfunction (28-day mortality ~23%) 7
  • ACLF-2: two organ failures (28-day mortality ~31%) 7
  • ACLF-3: three to six organ failures (28-day mortality ~74%) 7

Hepatic Encephalopathy Classification

• Hepatic encephalopathy is classified into four grades based on severity 1:
  • Grade I: shortened attention span, altered sleep rhythm 1
  • Grade II: inappropriate behavior, somnolence 1
  • Grade III: confusion, gross disorientation 1
  • Grade IV: coma, no response to painful stimuli 1

Diagnostic Considerations

• Differential diagnosis of hepatic encephalopathy should include metabolic disorders, substance-related disorders, neurological disorders, and psychiatric conditions 1
• The CLIF-SOFA score evaluates six major organ systems: liver (bilirubin), coagulation (INR), brain (encephalopathy), kidney (creatinine), circulation (blood pressure/vasopressors), and respiration (PaO2/FiO2 ratio) 6, 4
• Laboratory markers are critical for diagnosis, with bilirubin and coagulopathy being the hallmarks of liver failure 4

Management Principles

• Early identification and treatment of precipitating factors is crucial, particularly for ACLF 1, 4
• Patients with ALF should be systematically referred to a liver transplant unit 4
• Specific management includes antivirals for hepatitis B, corticosteroids for autoimmune hepatitis, and supportive care for organ failures 4
• Liver transplantation remains the definitive treatment for patients with poor prognostic indicators 4, 3