Child-Pugh Score Calculator

Bilirubin reflects the liver’s ability to conjugate and excrete haem breakdown products. In cirrhosis, progressive hepatocyte loss and intrahepatic shunting impair bilirubin clearance. Rising bilirubin is one of the most reliable markers of deteriorating hepatic function.

Important caveats: Gilbert syndrome (present in ~5–10% of the population) can elevate unconjugated bilirubin without hepatic impairment. Haemolysis, biliary obstruction, and sepsis can also raise bilirubin independently of cirrhosis severity. In primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), modified Child-Pugh cut-offs have been proposed because cholestatic disease causes disproportionate bilirubin elevation relative to hepatocellular function.

Albumin is produced exclusively by the liver, with a half-life of approximately 20 days. It is the most abundant plasma protein and is essential for maintaining oncotic pressure and transporting hormones, drugs, and bilirubin. In cirrhosis, falling albumin levels reflect diminishing synthetic capacity.

However, albumin is a negative acute-phase reactant — it falls in any inflammatory state, malnutrition, nephrotic syndrome, and protein-losing enteropathy. Exogenous albumin infusions (commonly given in cirrhosis for spontaneous bacterial peritonitis or large-volume paracentesis) will transiently raise levels and may artificially improve the Child-Pugh score without reflecting true hepatic improvement.

The liver synthesises most clotting factors (I, II, V, VII, IX, X, XI, XII) and anticoagulant proteins (protein C, protein S, antithrombin). INR prolongation in cirrhosis reflects reduced production of the vitamin K-dependent factors (II, VII, IX, X). Factor VII has the shortest half-life (~6 hours), making INR an early marker of acute hepatic decompensation.

Key confounders include warfarin or direct oral anticoagulant use (which invalidates INR as a liver function marker), vitamin K deficiency (common in cholestatic disease and malnutrition), disseminated intravascular coagulation, and congenital coagulopathies. When anticoagulants are in use, INR cannot be reliably incorporated into the Child-Pugh score.

Ascites results from portal hypertension, splanchnic vasodilation, sodium retention, and reduced oncotic pressure in cirrhosis. Its presence indicates significant decompensation. Ascites grading in the Child-Pugh system divides into absent, mild/controlled (responsive to diuretics), and moderate-to-severe/refractory.

The subjective nature of ascites assessment is a recognised limitation of the score. Ascites can be masked by effective diuretic therapy, and the distinction between “mild” and “moderate-to-severe” varies between observers. Imaging (ultrasound) provides more objective quantification. Refractory ascites — defined as non-responsive to maximal diuretic therapy or recurrence within four weeks of large-volume paracentesis — carries a particularly poor prognosis with median survival of approximately six months.

Hepatic encephalopathy (HE) results from the accumulation of neurotoxins — primarily ammonia — due to impaired hepatic clearance and portosystemic shunting. The West Haven classification grades HE from I (mild confusion, sleep disturbance) through IV (coma). For Child-Pugh scoring, grades I–II count as 2 points and grades III–IV as 3 points.

HE grading is the most subjective of the five Child-Pugh parameters. Minimal hepatic encephalopathy (detected only by psychometric testing) is not captured by the score, yet may affect quality of life and driving fitness. Precipitants such as infection, gastrointestinal bleeding, constipation, electrolyte disturbance, and sedative medications can worsen HE independently of underlying liver disease severity. Always identify and treat reversible triggers before attributing HE grade to baseline hepatic function.

Two of the five parameters — ascites and hepatic encephalopathy — rely on clinical judgement rather than objective laboratory values. Inter-observer variability in grading these parameters is significant. One clinician may grade diuretic-responsive ascites as “mild” while another considers it “moderate.” Similarly, the distinction between West Haven grade I and grade II encephalopathy is notoriously inconsistent.

This subjectivity means the same patient may receive different Child-Pugh scores from different assessors. This is one of the principal reasons the MELD score (which uses only objective laboratory values) was adopted for transplant organ allocation.

The Child-Pugh score has a maximum of 15 points, and Class C spans 10–15. A patient scoring 10 (early decompensation) has a meaningfully different prognosis from one scoring 15 (severe multi-organ failure), yet both are categorised as Class C. The score lacks granularity at the sickest end of the spectrum.

For patients in the Class C range, the MELD score provides better discrimination because it is a continuous variable without a ceiling. This is particularly important for transplant prioritisation, where the difference between a MELD of 25 and 40 is clinically critical but would not be captured by Child-Pugh alone.

The Child-Pugh score is designed to reflect chronic hepatic function, not acute illness severity. Scoring a patient during an episode of variceal bleeding, spontaneous bacterial peritonitis, or acute-on-chronic liver failure will overestimate their baseline disease severity. Bilirubin and INR may be transiently worsened, ascites may be newly tense, and encephalopathy may be precipitated by reversible factors.

Best practice is to score patients at their clinical baseline or after stabilisation of an acute event. If the score is needed urgently (e.g., for surgical risk assessment during an acute admission), document clearly that it was obtained during a decompensation episode and may not reflect the chronic state.

The Child-Pugh score treats all cirrhosis aetiologies equally, despite well-documented differences in prognosis. Alcoholic cirrhosis with ongoing drinking carries a worse trajectory than hepatitis C-related cirrhosis that has achieved sustained virological response, even at the same Child-Pugh class. Similarly, the score does not incorporate renal function — hepatorenal syndrome is a powerful negative prognostic indicator that Child-Pugh ignores.

The MELD score partially addresses this by including creatinine, but neither score captures aetiology-specific prognosis. Consider the complete clinical picture, including the underlying cause of cirrhosis and its treatability, when counselling patients.

Therapeutic interventions can improve individual Child-Pugh components without necessarily improving the underlying hepatic function. Albumin infusions raise serum albumin, diuretics reduce ascites, lactulose and rifaximin improve encephalopathy grading, and vitamin K supplementation can partially correct INR. A patient receiving aggressive supportive care may score as Class A or B while their underlying liver disease remains severe.

When using Child-Pugh for surgical risk or transplant discussions, consider whether the current score reflects native liver function or treatment-augmented values. Documenting both the “on treatment” and estimated “off treatment” class can be clinically useful.