Child-Pugh Score: Assessing Liver Disease Severity
The Child-Pugh score is a clinical tool used to evaluate the prognosis and severity of chronic liver disease. By analyzing five specific clinical measures, healthcare providers can categorize the degree of liver dysfunction and determine the appropriate course of treatment for patients.
Each of the five measures is assigned a value of 1, 2, or 3 points, where a higher score indicates a more severe derangement of liver function. The final total score provides a standardized way to communicate the patient's status.
Key Facts
- The score utilizes five distinct clinical measures of liver disease.
- Each measure is scored on a scale of 1 to 3.
- Only one coagulation measure (either Prothrombin time or INR) is used per calculation.
- Modified bilirubin thresholds are used for patients with PSC and PBC.
- Higher total scores correlate with more severe liver impairment.
The Five Clinical Measures
To calculate the score, clinicians evaluate biochemical markers and physical symptoms. These markers reflect the liver's ability to synthesize proteins, clear bilirubin, and maintain neurological function.
Biochemical Markers
The score considers Total Bilirubin (a byproduct of red blood cell breakdown), Serum Albumin (a protein produced by the liver), and a measure of blood clotting efficiency. For clotting, clinicians use either the Prothrombin time (the time it takes for blood to clot) or the INR (International Normalized Ratio), but never both simultaneously.
Clinical Symptoms
Two physical manifestations of liver failure are assessed: Ascites (the accumulation of fluid in the abdominal cavity) and Hepatic Encephalopathy (a decline in brain function caused by the liver's inability to remove toxins from the blood).
[ไม่มีภาพประกอบ]Scoring Criteria and Reference Table
The following table outlines the point system used to determine the severity of each clinical measure.
| Measure | 1 Point | 2 Points | 3 Points |
|---|---|---|---|
| Total bilirubin, μmol/L (mg/dL) | < 34 (< 2) | 34–50 (2–3) | > 50 (> 3) |
| Serum albumin, g/dL | > 3.5 | 2.8–3.5 | < 2.8 |
| Prothrombin time, prolongation (s) | < 4.0 | 4.0–6.0 | > 6.0 |
| INR | < 1.7 | 1.7–2.3 | > 2.3 |
| Ascites | None | Mild (or suppressed with medication) | Moderate to severe (or refractory) |
| Hepatic encephalopathy | None | Grade I–II | Grade III–IV |
Special Considerations for PSC and PBC
In cases of Primary Sclerosing Cholangitis (PSC) and Primary Biliary Cholangitis (PBC), the standard bilirubin references may be adjusted. Because these specific diseases are characterized by high levels of conjugated bilirubin, a modified Child-Pugh score is sometimes employed.
Under these modified guidelines, the bilirubin thresholds are increased as follows:
- 1 point: Upper limit of 68 μmol/L (4 mg/dL)
- 2 points: Upper limit of 170 μmol/L (10 mg/dL)
Frequently Asked Questions
Can I use both Prothrombin time and INR in the calculation?
No. To avoid double-counting the same physiological function, you must use either the prothrombin time or the INR, but not both.
What does a score of 3 indicate for a specific measure?
A score of 3 indicates the most severe derangement or impairment for that particular clinical measure.
Why is the bilirubin score different for PSC and PBC patients?
The references are modified for PSC and PBC because these conditions typically feature higher levels of conjugated bilirubin, which would otherwise skew the severity results.
What is the difference between mild and refractory ascites in this score?
Mild ascites may be suppressed with medication and earns 2 points, whereas moderate to severe or refractory ascites (which does not respond to treatment) earns 3 points.