The Child-Turcotte-Pugh (CTP) score is a widely recognized medical system used to evaluate the severity of chronic liver disease, particularly cirrhosis. This scoring system helps healthcare professionals understand how well a patient’s liver is functioning and provides an indication of the disease’s progression. Its primary purpose is to predict the patient’s outlook, known as prognosis, and to guide appropriate treatment decisions for managing liver conditions.
What the CTP Score Measures
The CTP score relies on five specific clinical and laboratory parameters, each reflecting a different aspect of liver function or its complications. Total bilirubin level indicates how effectively the liver processes bilirubin, a yellow compound produced when red blood cells break down. Elevated bilirubin can lead to jaundice, a yellowing of the skin and eyes, which signifies impaired liver function.
Serum albumin level measures the amount of albumin, a protein synthesized by the liver. Albumin helps maintain fluid balance and transports various substances; low levels suggest the liver’s reduced ability to produce proteins. Prothrombin time (PT) or International Normalized Ratio (INR) assesses the blood’s clotting ability. A prolonged PT or elevated INR indicates that the liver is not producing enough clotting factors, increasing the risk of bleeding.
The presence and severity of ascites, fluid accumulation in the abdomen, also contribute. This fluid buildup occurs due to high pressure in the blood vessels supplying the liver and low albumin levels. Hepatic encephalopathy, a brain disorder caused by liver dysfunction, is the fifth parameter. This condition manifests as confusion, disorientation, or changes in consciousness because the liver cannot adequately remove toxins from the blood, allowing them to accumulate in the brain.
Calculating the CTP Score
Each of the five parameters in the CTP score is assigned a specific point value based on its severity or measured level:
- Total bilirubin: <2 mg/dL (1 point), 2-3 mg/dL (2 points), >3 mg/dL (3 points).
- Serum albumin: >3.5 g/dL (1 point), 2.8-3.5 g/dL (2 points), <2.8 g/dL (3 points).
- International Normalized Ratio (INR): <1.7 (1 point), 1.7-2.3 (2 points), >2.3 (3 points).
- Ascites: None (1 point), Slight or controlled with medication (2 points), Moderate to severe and refractory to treatment (3 points).
- Hepatic encephalopathy: None (1 point), Mild to moderate (Grade I-II, 2 points), Severe (Grade III-IV, 3 points).
After each of the five parameters has been assigned its respective points, these individual point values are added together to determine a total CTP score, which can range from a minimum of 5 to a maximum of 15 points.
Understanding CTP Classes and Prognosis
The total CTP score categorizes patients into three distinct classes, each indicating a different level of liver disease severity and associated prognosis.
Class A (5-6 points) represents the least severe form of liver disease, often described as well-compensated cirrhosis. Patients in this class generally have a more favorable outlook, with an estimated one-year survival rate of approximately 95 percent. The liver maintains a relatively high level of function, and complications are typically minimal.
Class B (7-9 points) indicates moderately severe liver disease with significant functional compromise. Individuals in this category experience more noticeable symptoms and may have a higher risk of complications compared to Class A. The one-year survival rate for Class B patients is generally around 75 percent, reflecting a more guarded prognosis. Management often focuses on preventing further deterioration and addressing emerging complications.
Class C (10-15 points) signifies the most severe, decompensated stage of liver disease. This class indicates substantial liver dysfunction and a higher likelihood of severe complications, such as recurrent ascites, bleeding, or severe encephalopathy. The prognosis for Class C patients is considerably less favorable, with an estimated one-year survival rate of about 50 percent. This classification highlights the urgent need for comprehensive medical intervention and potentially liver transplantation.
The CTP Score in Medical Practice
Beyond its role in predicting prognosis, the CTP score serves as a practical tool for healthcare providers to guide treatment strategies for patients with chronic liver disease. It helps clinicians assess the risk associated with various medical procedures, particularly before surgery, allowing for adjustments in care to improve patient safety. The score provides a standardized way to communicate the overall health status of a patient’s liver, facilitating informed decision-making among medical teams.
The CTP score is often considered alongside other assessment tools in complex cases. The Model for End-Stage Liver Disease (MELD) score is another system frequently used in liver disease management. Unlike the CTP score, which incorporates subjective clinical assessments, the MELD score relies solely on objective laboratory values: bilirubin, creatinine, and INR. In the United States, the MELD score is used to prioritize patients on the waiting list for liver transplants, as it is considered a more objective measure for allocating organs based on short-term mortality risk.