How is the Child-Pugh score calculated?

How to Calculate the Child-Pugh Score

The Child-Pugh score is calculated by adding points for five parameters: total bilirubin, serum albumin, INR, ascites, and hepatic encephalopathy, with a total score ranging from 5 to 15 points. 1

Scoring Components

1. Total Serum Bilirubin

• Bilirubin < 2 mg/dl: 1 point
• Bilirubin 2-3 mg/dl: 2 points
• Bilirubin > 3 mg/dl: 3 points

2. Serum Albumin

• Albumin > 3.5 g/dl: 1 point
• Albumin 2.8-3.5 g/dl: 2 points
• Albumin < 2.8 g/dl: 3 points

3. INR (International Normalized Ratio)

• INR < 1.7: 1 point
• INR 1.7-2.2: 2 points
• INR > 2.2: 3 points

4. Ascites

• None: 1 point
• Slight/Mild: 2 points
• Moderate: 3 points

5. Hepatic Encephalopathy

• None: 1 point
• Grade 1-2: 2 points
• Grade 3-4: 3 points

Classification

After calculating the total score (sum of all five parameters), patients are classified into one of three Child-Pugh classes:

• Class A (mild): 5-6 points
• Class B (moderate): 7-9 points
• Class C (severe): 10-15 points

Clinical Significance

The Child-Pugh classification is widely used to:

• Assess severity of liver disease, primarily cirrhosis 1
• Predict prognosis in patients with liver cirrhosis 2
• Guide treatment decisions for various conditions including:
  • Anticoagulation therapy in atrial fibrillation patients with liver disease 1
  • Evaluation for liver transplantation 1
  • End-stage organ failure assessment 1

Anticoagulation Decisions Based on Child-Pugh Score

• Child-Pugh A (mild): Most direct oral anticoagulants can be used with caution
• Child-Pugh B (moderate): Limited options (apixaban, dabigatran, or edoxaban may be used with caution)
• Child-Pugh C (severe): Avoid direct oral anticoagulants 1

Advantages and Limitations

Advantages

• Simple to calculate at bedside
• Includes both laboratory and clinical parameters
• Well-established prognostic value 2
• Good discrimination power for survival prediction 2

Limitations

• Includes subjective variables (ascites, encephalopathy) 1
• Does not include renal function, which is an important prognostic factor
• May be less accurate than newer models like MELD for certain applications 1

Common Pitfalls to Avoid

1. Misclassification of ascites or encephalopathy: These subjective components require careful clinical assessment
2. Using outdated laboratory values: Always use the most recent values for accurate scoring
3. Overlooking confounding factors: Certain medications or conditions may affect INR or albumin levels
4. Failing to reassess: The Child-Pugh score can change over time as liver function changes

The Child-Pugh score remains a valuable tool for assessing liver function despite the development of newer prognostic models. Its simplicity, availability, low cost, and good discrimination power make it a useful method to estimate prognosis in patients with cirrhosis of the liver 2.