Prioritization of patients (age ≥ 12) for liver transplantation (UNOS/OPTN)
Estimating 90-day mortality in patients with end-stage liver disease (ESLD)
To guide the frequency of lab monitoring for transplant candidates
Predicting perioperative mortality in patients with cirrhosis undergoing non-transplant surgery
MELD-Na Integration
In January 2016, UNOS updated the original MELD formula to include Serum Sodium (Na). Because hyponatremia is a potent independent predictor of mortality in cirrhosis, MELD-Na is the current standard for liver allocation.
Section 2
Formula & Logic
Primary Lab Variables
01
Bilirubin (Total): Marker of hepatic excretory function.
02
INR: Marker of hepatic synthetic function.
03
Creatinine: Marker of renal function (critical in hepatorenal syndrome).
04
Sodium (Na): Marker of effective circulatory volume and portal hypertension.
Formula (The MELD-Na version)
The score is calculated as a complex log-linear function. If MELD > 11, the Sodium component is applied. Scores are capped at 40.
Mortality Estimates (90-day)
Score ≥ 40
71% Mortality
Score 30–39
52% Mortality
Score 20–29
19% Mortality
Score 10–19
6% Mortality
Section 3
Pearls/Pitfalls
The Sodium Advantage
Before the MELD-Na update, many patients with severe portal hypertension-related hyponatremia had "low" MELD scores despite a high risk of death. MELD-Na correctly re-prioritizes these patients, ensuring that those with significant ascites and salt-handling issues receive transplants sooner.
MELD 3.0 — The 2024 Future
OPTN/UNOS is transitioning to MELD 3.0, which incorporates sex-based adjustments (correcting for low creatinine in women) and albumin. MELD 3.0 seeks to further reduce the "biological disadvantage" females face on the transplant waitlist.
Clinical Pearls
Creatinine is capped at 4 mg/dL; Dialysis patients automatically receive 4 mg/dL to reflect maximum renal score
Exception Points (MELD Exceptions) are granted for HCC, hepatopulmonary syndrome, and other conditions not captured by labs
Small changes in MELD (e.g., 2 points) are significant; a rising MELD is a marker of rapid clinical decompensation
Section 4
Next Steps
Clinical Action
01
MELD ≥ 15: Evaluation for liver transplant referral is mandatory.
02
MELD 25+: Frequent lab update (every 7 days) required for UNOS status maintenance.
03
Low MELD (< 10): Surveillance and optimization of comorbidities.
Complementary Liver Tools
Child-Pugh Score (Functional Stage)
Maddrey Discriminant Function (Alcoholic Hepatitis)
FIB-4 Index (Fibrosis Screening)
Section 5
Evidence Appraisal
The Original MELD
A model to predict survival in patients with end-stage liver disease.
Kamath PS et al. • Hepatology. 2001;33(2):464-70. Foundational MELD paper.
Originally developed at the Mayo Clinic to predict survival in patients undergoing TIPS procedures (Transjugular Intrahepatic Portosystemic Shunt). In 2002, UNOS (the United Network for Organ Sharing) adopted it as the replacement for the Child-Pugh score to remove subjectivity from liver allocation.
