The Child-Turcotte-Pugh (CTP) score is a standardized clinical system used in hepatology to evaluate the severity of chronic liver disease, particularly cirrhosis. Originally developed by doctors Child and Turcotte in 1964 and later modified by Pugh in 1972, the score serves as a rapid, accessible method for classifying a patient’s liver function. It combines observable clinical signs with routine laboratory blood test results to produce a single, simple metric. This classification helps medical professionals quickly gauge the overall health of the liver and assess the patient’s prognosis.
What the CTP Score Measures
The fundamental purpose of the CTP score is to assess the functional reserve of the liver. Chronic liver diseases, especially cirrhosis, cause widespread scarring that prevents liver cells from working efficiently. The score was initially created to help predict the likelihood of a patient surviving a major surgery, particularly procedures involving the portal vein. By evaluating both the synthetic and excretory capacity of the liver, the CTP system provides a snapshot of disease progression. This allows doctors to classify the severity of the liver dysfunction into distinct categories, which offers a general indication of the patient’s long-term outlook.
Components Used for Calculation
The CTP score is calculated using five specific variables, each assigned a score of one, two, or three points based on the degree of abnormality or severity. Three of these components are laboratory values reflecting the liver’s synthetic and detoxification capabilities. The remaining two components are clinical assessments of observable symptoms.
Serum Albumin reflects the liver’s synthetic capability. Levels greater than 3.5 g/dL earn one point, while levels below 2.8 g/dL receive three points. Total Bilirubin measures the organ’s ability to detoxify; low levels below 2 mg/dL receive one point, and high levels above 3 mg/dL receive three points.
The International Normalized Ratio (INR), or Prothrombin Time, assesses the time it takes for blood to clot. Since the liver produces clotting factors, a prolonged INR indicates poor synthetic function, with values greater than 2.3 receiving three points. The two clinical parameters are Ascites (fluid buildup in the abdomen) and Hepatic Encephalopathy (brain dysfunction caused by uncleared toxins).
For Ascites, scoring ranges from one point (no fluid) to three points (severe fluid refractory to treatment). Hepatic Encephalopathy is scored based on the severity of altered mental status, ranging from one point (no symptoms) to three points (severe confusion or coma). The final CTP score is the sum of the points from these five variables, resulting in a total score ranging from five to fifteen.
Understanding the Score Classes
The total points accumulated from the five components determine the patient’s classification into one of three severity classes: Class A, Class B, or Class C. This classification provides immediate prognostic information.
A total score of five to six points places a patient in Child-Pugh Class A, representing the least severe form of cirrhosis. Patients in this category generally have the most favorable prognosis, with an estimated one- to five-year survival rate of approximately 95 percent. A score ranging from seven to nine points corresponds to Child-Pugh Class B.
Class B patients have a significantly compromised liver function, and their estimated one- to five-year survival rate drops to about 75 percent. The highest scores, ranging from 10 to 15 points, result in a classification of Child-Pugh Class C. For patients in Class C, the prognosis is considerably poorer, with an estimated one- to five-year survival rate falling to around 50 percent.
Using the Score in Medical Planning
The CTP score remains an important tool for clinical management of patients with chronic liver disease. One of its primary contemporary uses is in assessing the risk for non-liver-related surgeries. Patients classified as Child-Pugh Class C face a high risk of complications and mortality when undergoing major operations.
Historically, the CTP score was the main system used for evaluating patients for liver transplantation. However, the Model for End-Stage Liver Disease (MELD) score has largely replaced CTP for transplant prioritization. The MELD score uses only objective laboratory values (bilirubin, creatinine, and INR) and is considered more accurate for predicting three-month mortality, which is the timeframe most relevant for transplant waiting lists.
Despite the shift to MELD for transplantation, the CTP score is still used globally to guide various treatment and medication decisions. The CTP class can sometimes be referenced in drug prescribing information to suggest appropriate dose adjustments for medications metabolized by the liver. Its simplicity and inclusion of clinical signs like ascites and encephalopathy make it a valuable, quick assessment tool for overall patient status in routine clinical practice.