What is the Child-Pugh (Child-Pugh score) score and its significance in liver disease prognosis?

Child-Pugh Score and Its Significance in Liver Disease Prognosis

The Child-Pugh score is a validated clinical tool that assesses hepatic functional reserve in patients with cirrhosis by incorporating laboratory measurements (serum albumin, bilirubin, prothrombin time/INR) and clinical assessments (encephalopathy and ascites) to classify patients as having compensated (class A) or decompensated (classes B and C) cirrhosis, providing critical prognostic information for mortality risk and treatment decisions. 1

Components of the Child-Pugh Score

The Child-Pugh score includes five parameters, each scored from 1-3 points:

• Encephalopathy:

  • None (1 point)
  • Grade 1-2 (2 points)
  • Grade 3-4 (3 points) 1

• Ascites:

  • Absent (1 point)
  • Slight (2 points)
  • Moderate (3 points) 1

• Bilirubin (mg/dL):

  • 1-2 (1 point)
  • 2-3 (2 points)

  • 3 (3 points) 1

  • For primary biliary cirrhosis: 1-4 mg/dL (1 point), 4-10 mg/dL (2 points), >10 mg/dL (3 points) 1

• Albumin (g/dL):

  • 3.5 (1 point)

  • 2.8-3.5 (2 points)
  • <2.8 (3 points) 1

• Prothrombin time (seconds prolonged) or INR:

  • 1-4 seconds or INR <1.7 (1 point)
  • 4-6 seconds or INR 1.7-2.3 (2 points)

  • 6 seconds or INR >2.3 (3 points) 1

Classification and Prognostic Value

The total score classifies patients into three categories:

• Class A: 5-6 points (compensated cirrhosis)
• Class B: 7-9 points (moderate functional compromise)
• Class C: 10-15 points (decompensated cirrhosis) 1, 2

The prognostic implications of each class are significant:

• Class A: 90% chance of surviving 5 years 1
• Class B: 80% chance of surviving 5 years 1
• Class C: More than one-third of patients will die within 1 year 1, 2

Clinical Applications

• Treatment decision-making: Guides therapeutic interventions and helps determine eligibility for procedures such as surgery, transplantation, and other treatments 1

• Surgical risk assessment: Used to evaluate perioperative risk in patients undergoing hepatic resection or other surgical procedures 1

• Transplantation evaluation: Helps identify candidates who would benefit from liver transplantation 1

• Clinical trial stratification: Commonly used to stratify patients in clinical trials of liver disease treatments 1

• Hepatocellular carcinoma management: Incorporated into treatment algorithms for HCC, including the Barcelona Clinic Liver Cancer (BCLC) staging system 1

Advantages and Limitations

Advantages:

• Simple to calculate at the bedside without complex equipment 1
• Widely validated and accepted in clinical practice 2, 3
• Incorporates both laboratory and clinical parameters 1
• Good discriminating power for survival outcomes 2, 3

Limitations:

• Includes subjective components (ascites, encephalopathy) that may introduce bias 1
• Limited dynamic range (e.g., a bilirubin of 5 mg/dL and 15 mg/dL would be scored identically) 1
• Does not include assessment of renal function, which is an important prognostic factor 1
• Does not capture temporary events that may indicate end-stage liver disease (renal failure, spontaneous bacterial peritonitis, hyponatremia) 1

Comparison with Other Prognostic Models

MELD Score:

• Uses bilirubin, creatinine, and INR (more objective parameters) 1
• Better predictor of short-term (3-month) mortality 1
• Used for liver transplant allocation 1
• Includes assessment of renal function 1
• More sensitive dynamic range than Child-Pugh 1
• May be superior for patients on transplant waiting lists 1

ALBI Score:

• Uses only albumin and bilirubin levels 1, 4
• Allows subgrouping of Child-Pugh A patients 1
• Eliminates subjective variables 1
• Useful for predicting post-hepatectomy liver failure 4

Clinical Pearls and Pitfalls

• The development of complications such as ascites, variceal bleeding, hepatic encephalopathy, spontaneous bacterial peritonitis, or hepatorenal syndrome significantly impacts prognosis, with 5-year survival rates dropping to 20-50% 1

• The most ominous complications are spontaneous bacterial peritonitis (less than 50% one-year survival) and type I hepatorenal syndrome (median survival less than 2 weeks) 1

• Evidence of portal hypertension (esophagogastric varices, splenomegaly, splenorenal shunts, thrombocytopenia) should be evaluated alongside the Child-Pugh score for comprehensive assessment 1

• When using Child-Pugh for treatment decisions, consider that it was originally developed to assess mortality risk following portacaval shunt surgery 1, 2

• A 2-point worsening of the Child-Pugh score or progression from Child class A to B accurately measures worsening of a patient's health status and increased mortality risk 1