Child-Pugh Classification
On this page
Direct answer
Child-Pugh classification is a bedside score that grades the severity of cirrhosis from five components: bilirubin, albumin, prothrombin time or INR, ascites and encephalopathy. Totals of 5 or 6 are class A, 7 to 9 are class B and 10 to 15 are class C, with class C carrying the poorest prognosis and the highest surgical risk. The class also guides drug dosing in liver disease.
What you must remember
- Bilirubin: Under 2 mg/dL scores 1; 2 to 3 mg/dL scores 2; above 3 mg/dL scores 3.
- Albumin: Above 3.5 g/dL scores 1; 2.8 to 3.5 g/dL scores 2; below 2.8 g/dL scores 3.
- INR: Under 1.7 scores 1; 1.7 to 2.3 scores 2; above 2.3 scores 3.
- Ascites: None scores 1; mild or controlled on diuretics scores 2; moderate to severe or refractory scores 3.
- Encephalopathy: None scores 1; grade 1 to 2, or controlled with medication, scores 2; grade 3 to 4, or refractory, scores 3.
- Classes: A is well compensated, B is significant functional compromise, and C is decompensated with the poorest prognosis.
A worked score: a patient on lactulose
Consider a patient with cirrhosis whose bilirubin is 3.4 mg/dL, albumin 2.6 g/dL and INR 1.9. Ascites is mild and controlled on diuretics, and encephalopathy is grade 1 but suppressed with lactulose.
- Score bilirubin and albumin: Bilirubin above 3 scores 3, and albumin below 2.8 scores 3.
- Score the INR: An INR of 1.9 scores 2.
- Score ascites: Controlled ascites scores 2.
- Score encephalopathy: Encephalopathy suppressed by medication also scores 2.
- Add the total: The total is 12, which places the patient in class C, even though three components score only 2 each.
The class then drives decisions. Class C patients are generally not fit for elective surgery, and their drug handling is altered because hepatic clearance and plasma protein binding change.
Many drug labels grade hepatic impairment by Child-Pugh class, and dose reduction, avoidance of sedatives and cautious use of NSAIDs are standard. Paracetamol is commonly limited to a lower daily maximum in cirrhosis, while opioids and benzodiazepines accumulate and need careful dosing. The score is therefore a practical guide to safety, not only a prognostic number.
Where the exam tries to catch you
Child-Pugh questions turn on four recurring traps.
- Trap: Mixing up Child-Pugh with MELD. Correct: Child-Pugh guides prognosis, surgical risk and drug dosing. MELD, which uses bilirubin, INR, creatinine and sodium, is preferred for transplant allocation because it is continuous and objective.
- Trap: Scoring one component dramatically and assuming the class changes. Correct: A bilirubin of 3.4 adds only three points, and the class depends on the total.
- Trap: Scoring controlled ascites and encephalopathy as worst. Correct: Controlled ascites scores 2, and encephalopathy suppressed by lactulose scores 2, not 3.
- Trap: Reading a high INR as liver failure alone. Correct: The INR can be raised by anticoagulants, so a high INR in a patient on warfarin does not alone earn the maximum points.
Frequently asked questions
What total score on Child-Pugh classification defines class C?
A total score of 10 to 15 defines Child-Pugh class C, the most severe category in cirrhosis. Class A scores 5 to 6 and class B scores 7 to 9.
Why does Child-Pugh classification include albumin and INR?
Albumin and INR reflect the liver's synthetic function, since albumin and clotting factors are made by hepatocytes. Bilirubin and encephalopathy reflect excretory and detoxifying function, so the score captures both synthetic and clearance failure.
Which score is preferred for liver transplant listing instead of Child-Pugh classification?
The MELD score is preferred for liver transplant listing because it uses bilirubin, INR, creatinine and sodium and is continuous and objective. Child-Pugh classification is used mainly for prognosis, surgical risk and drug dosing.
How is encephalopathy scored when it is controlled on lactulose?
Encephalopathy controlled on lactulose or other treatment is scored as 2 points in Child-Pugh classification, because it is medically suppressed. Only refractory or grade 3 to 4 encephalopathy earns the maximum three points.
Does a Child-Pugh class C patient need a lower paracetamol dose?
Child-Pugh class C patients usually need a lower daily paracetamol ceiling, because hepatic clearance is reduced. Sedatives and NSAIDs are also avoided, and other hepatically cleared drugs are dosed cautiously.