MELD Score Calculator (MELD-Na for End-Stage Liver Disease)
Estimate 3-month mortality for patients 12 years and older with end-stage liver disease. This tool calculates both the Original Model for End-Stage Liver Disease (MELD) and the UNOS/OPTN MELD-Na score used for transplant prioritization.
Patient Parameters
Enter patient labs to generate the MELD-Na Score and estimate 3-month mortality risk.
Calculation & Unit Logic Applied
Dialysis Rule: If a patient has had ≥2 dialysis treatments in the past 7 days, the UNOS algorithm automatically sets the Creatinine value to 4.0 mg/dL.
Unit Conversions: Automatically converts Creatinine (µmol/L to mg/dL ÷ 88.4) and Bilirubin (µmol/L to mg/dL ÷ 17.1) for execution through the standard logarithmic equations.
The Evolution of the MELD Score
The Model for End-Stage Liver Disease (MELD) was originally developed in 2000 to predict survival in patients undergoing Transjugular Intrahepatic Portosystemic Shunt (TIPS) procedures. In 2002, the United Network for Organ Sharing (UNOS) adopted it to prioritize the allocation of deceased donor livers for transplantation, replacing the older Child-Pugh score due to MELD’s purely objective, lab-based parameters.
In 2016, OPTN/UNOS updated the algorithm to the MELD-Na score. Including serum sodium accounts for the severe prognostic implications of dilutional hyponatremia in advanced cirrhosis, effectively improving allocation equity.
Estimated 3-Month Mortality
The primary clinical utility of the MELD score is predicting 90-day mortality if the patient does not receive a liver transplant. As the score increases, mortality risk rises exponentially.
| MELD Score Bracket | Estimated 3-Month Mortality | Clinical Context |
|---|---|---|
| ≤ 9 | 1.9% | Low priority for transplant. Manage underlying disease. |
| 10 – 19 | 6.0% | Considered for transplant listing. Monitor closely. |
| 20 – 29 | 19.6% | High risk. Active transplant candidates. High frequency of lab draws. |
| 30 – 39 | 52.6% | Critical condition. High priority on the UNOS waitlist. |
| 40 (Maximum) | 71.3% | Eminent mortality without immediate transplant intervention. |
OPTN/UNOS Mathematical Boundaries
To prevent mathematical errors (like taking the logarithm of zero) and to cap extreme values, the OPTN applies strict bounds to the formula:
- Lower Bounds: If Creatinine, Bilirubin, or INR is less than 1.0, it is automatically set to 1.0.
- Creatinine Cap: The maximum allowable value for Creatinine is 4.0 mg/dL.
- Dialysis: If a patient has received 2 or more dialysis treatments in the prior week, the Creatinine is defaulted to 4.0 mg/dL.
- Sodium Bounds: For the MELD-Na calculation, Sodium is bounded to a minimum of 125 mEq/L and a maximum of 137 mEq/L.
MELD 3.0: The Future of Liver Allocation
In July 2023, OPTN implemented MELD 3.0. While MELD-Na remains clinically ubiquitous in legacy systems, MELD 3.0 introduces two major changes: it incorporates serum Albumin, and it adds a specific modifier (+1.33 points) for female patients to address historical disparities in transplant access due to generally lower muscle mass and resulting lower baseline creatinine levels.
