How is hepatic failure graded in patients with liver disease?

Grading of Hepatic Failure

Hepatic failure is graded using different classification systems depending on whether the patient has acute liver failure (ALF) or chronic liver disease with cirrhosis, with the CLIF-SOFA score and ACLF grading system being the most prognostically accurate for critically ill cirrhotic patients. 1

Acute Liver Failure (ALF) Grading

For patients without preexisting liver disease who develop acute hepatocellular dysfunction, severity is classified based on prothrombin time (PT) and presence of encephalopathy 1:

• Severe ALF: PT ratio <50% 1
• Serious ALF: PT ratio <50% combined with hepatic encephalopathy 1

The key distinguishing feature is that ALF occurs in patients without preexisting liver disease and develops in less than 26 weeks 1.

Chronic Liver Disease and Cirrhosis Grading

Child-Pugh Score (Traditional Classification)

The Child-Pugh score categorizes cirrhotic patients into three classes (A to C) based on five parameters 1, 2:

• Serum albumin
• Serum bilirubin
• Prothrombin time
• Presence of ascites
• Hepatic encephalopathy

Child-Pugh classes:

• Class A: Score 5-6 (best prognosis) 2
• Class B: Score 7-11 (intermediate prognosis) 2
• Class C: Score 12-15 (worst prognosis) 2

This classification has been the reference standard for approximately three decades and demonstrates good discrimination power with significant differences in median survival between classes 2, 3.

MELD Score

The Model for End-Stage Liver Disease (MELD) score emerged as a modern alternative to Child-Pugh, using objective laboratory values (bilirubin, creatinine, INR) to predict mortality risk 3. Modified versions include MELD-Na (incorporating sodium) and Delta MELD 3.

ALBI Grade (Albumin-Bilirubin)

The ALBI grade provides an objective, reproducible measure of liver functional reserve using only albumin and bilirubin 4, 5:

• Grade I: Best liver function
• Grade II: Intermediate liver function
• Grade III: Worst liver function

The ALBI score demonstrates superior performance for predicting short-term outcomes (in-hospital and 30-day mortality) compared to Child-Pugh and MELD scores in patients with acute decompensation. 5

Acute-on-Chronic Liver Failure (ACLF) Grading System

For cirrhotic patients requiring ICU admission, the ACLF grading system using the CLIF-SOFA score provides the most accurate prognostic stratification and outperforms traditional Child-Pugh and MELD scores. 1

ACLF is defined as acute decompensation of cirrhosis combined with one or more extrahepatic organ failures and high short-term mortality (≥15% at 28 days) 1.

ACLF Grades Based on Organ Failures:

The CLIF-SOFA score classifies patients into four grades of severity based on the number and type of failing organs 1:

• No ACLF: No organ failure or single non-kidney organ failure without elevated creatinine
• ACLF Grade 1: Single kidney failure OR single non-kidney organ failure with creatinine 1.5-1.9 mg/dL OR hepatic encephalopathy grade I-II with creatinine 1.5-1.9 mg/dL
• ACLF Grade 2: Two organ failures
• ACLF Grade 3: Three or more organ failures

The ACLF grading system demonstrates superior predictive accuracy for ICU outcomes compared to Child-Pugh or MELD scores, making it the preferred classification for critically ill cirrhotic patients. 1

Hepatic Encephalopathy Grading (Component of Liver Failure Assessment)

Hepatic encephalopathy severity is graded using the West Haven Criteria 1:

• Grade 0: No detectable changes (may have minimal/covert HE on testing)
• Grade I: Mild alterations in consciousness, subtle personality changes, decreased attention, sleep disturbances, irritability, difficulty with complex cognitive tasks 6, 7
• Grade II: Mild disorientation (especially temporal), pronounced lethargy, inappropriate behavior, asterixis, dysarthric or slow speech 6, 7
• Grade III: Marked confusion, somnolence but arousable, severe disorientation 8
• Grade IV: Coma, unresponsive to stimuli 8

The Glasgow Coma Scale can also be used for grading overt hepatic encephalopathy 1.

Clinical Application and Pitfalls

Critical considerations when grading hepatic failure:

• Do not rely solely on ammonia levels for diagnosis, staging, or prognosis—they lack diagnostic value, though a normal ammonia level should prompt diagnostic reevaluation 1, 6
• ACLF is a dynamic syndrome that can develop rapidly in previously compensated cirrhotic patients when exposed to precipitating events (infection, bleeding, etc.) 1
• For ICU admission decisions, ACLF grading provides better prognostic information than traditional scores and should guide triage decisions 1
• The ALBI grade identifies prognostic subgroups within Child-Pugh classes, making it particularly useful for treatment selection and therapeutic sequencing 4
• Brain imaging (CT/MRI) does not contribute to grading but is essential to exclude alternative diagnoses, particularly intracranial hemorrhage which has 5-fold increased risk in cirrhotic patients 1