What is a Model for End-Stage Liver Disease (MELD) score?

Model for End-Stage Liver Disease (MELD) Score

The MELD score is a numerical scale ranging from 6 (less ill) to 40 (gravely ill) that uses three objective laboratory parameters—serum bilirubin, international normalized ratio (INR), and serum creatinine—to predict short-term mortality in patients with end-stage liver disease. 1, 2

Components and Calculation

• The MELD score was originally developed to assess short-term prognosis in patients undergoing transjugular intrahepatic portosystemic shunts (TIPS) 1, 2
• It incorporates three objective laboratory values: serum bilirubin, international normalized ratio (INR), and serum creatinine 2, 3
• The score provides a continuous scale from 6 to 40, which correlates with estimated 3-month survival rates ranging from 90% to 7%, respectively 1, 2

Clinical Applications

• The MELD score has been adopted by the United Network for Organ Sharing (UNOS) to prioritize patients on liver transplantation waiting lists according to their risk of death within 3 months 1
• A MELD score ≥15 is generally recommended as the threshold for listing patients for liver transplantation, as this score is associated with significantly increased mortality 2, 4
• Patients with MELD scores >10 should be referred for transplantation evaluation, especially when they develop evidence of hepatic dysfunction or experience their first major complication (ascites, variceal bleeding, or hepatic encephalopathy) 1

Advantages of MELD Score

• Uses only objective criteria, unlike the Child-Pugh score which includes subjective assessments of encephalopathy and ascites 1, 2
• Includes renal function (serum creatinine), which is an important prognostic marker in patients with liver disease 1, 2
• Implementation of the MELD score for organ allocation led to reduced mortality on transplant waiting lists without affecting post-transplant survival 3, 5

Limitations and Considerations

• The MELD score has not been validated as a predictor of survival in patients with cirrhosis who are not on a liver transplantation waiting list 1
• Serum creatinine can be an unreliable marker of renal dysfunction, especially in patients with cirrhosis 1
• The MELD score does not account for complications of portal hypertension or other clinical parameters that may affect prognosis 1

Comparison with Child-Pugh Score

• The Child-Pugh score includes five parameters: encephalopathy, ascites, bilirubin, albumin, and prothrombin time/INR 1, 2
• While the Child-Pugh score is useful for rapid assessment at the bedside, it has never been formally validated as a prognostic tool 1, 2
• Child-Pugh scores classify patients as having compensated (class A) or decompensated (classes B and C) cirrhosis 1

Recent Developments

• Several variations of the original MELD score have been proposed, including MELD-Na (incorporating serum sodium) and Delta MELD (measuring change in MELD over time) 2, 3
• The newest iteration, MELD 3.0, includes patient sex and serum albumin levels with adjusted weights for existing parameters, aiming to reduce waitlist mortality and improve access for female transplant candidates 6

Clinical Implications

• Higher MELD scores (>24) indicate increased risk for multidrug-resistant infections and may require modified antibiotic prophylaxis in perioperative settings 7
• The MELD score has proven effective in predicting outcomes in various clinical scenarios beyond transplantation, including patients with cirrhosis undergoing surgery, those with fulminant hepatic failure, or alcoholic hepatitis 3, 8