# MELD-Na Score (Sodium-Modified MELD)

Calculate the UNOS/OPTN MELD-Na score — the sodium-modified MELD used for adult liver transplant allocation in the US from January 2016 until superseded by MELD 3.0 in July 2023. First compute the base MELD(i) (same formula as MELD, clamped 6–40). If MELD(i) > 11: MELD-Na = MELD(i) + 1.32·(137 − Na) − 0.033·MELD(i)·(137 − Na), with sodium clamped to 125–137 mmol/L. If MELD(i) ≤ 11, MELD-Na = MELD(i) (no sodium adjustment). The result is rounded and clamped to 6–40. Rationale: hyponatremia (Na < 137) predicts worse waitlist mortality beyond what MELD(i) captures, so the score is inflated; the interaction term scales the sodium penalty down at very high MELD(i). Derived from Kim/Biggins 2008 (NEJM) and UNOS/OPTN policy. Not medical advice.

> Canonical page: https://elysiatools.com/en/tools/meld-na-score

- **Category:** Health

- **Keywords:** MELD-Na, MELD, sodium, hyponatremia, end-stage liver disease, cirrhosis, liver transplant, UNOS, OPTN, hepatology

## Overview

Calculate the UNOS/OPTN MELD-Na score from serum creatinine, total bilirubin, INR, sodium, and recent dialysis status. The result includes the sodium-adjusted score, base MELD(i), and calculation details in JSON. This tool is for reference and is not medical advice.

## Inputs

- **Serum Creatinine (mg/dL)** (number): Serum creatinine in mg/dL. Floored at 1.0, capped at 4.0 (4.0 if dialyzed). Must be positive.
- **Total Bilirubin (mg/dL)** (number): Total bilirubin in mg/dL. Floored at 1.0. Must be positive.
- **INR** (number): INR. Floored at 1.0. Must be positive.
- **Serum Sodium (mmol/L)** (number): Serum sodium in mmol/L. Clamped to 125–137 for the MELD-Na adjustment. Must be positive.
- **Dialysis ≥ 2× or CVVHD ≥ 24 h in past week** (checkbox): If dialyzed at least twice or on CVVHD for ≥ 24 hours in the past week, creatinine is set to 4.0 mg/dL.
- **Decimal Places** (number)

## When to use

- Estimate the sodium-modified MELD score using current laboratory values.
- Check how sodium below 137 mmol/L changes a base MELD(i) above 11.
- Review the capped inputs, dialysis adjustment, and final MELD-Na result in structured JSON.

## How it works

- Enter serum creatinine, total bilirubin, INR, and serum sodium.
- Select the dialysis option if dialysis occurred at least twice or CVVHD lasted at least 24 hours in the past week.
- The tool applies the stated input caps, calculates MELD(i), and limits it to 6–40.
- If MELD(i) is above 11, sodium is clamped to 125–137 mmol/L and applied to the MELD-Na formula; the final score is rounded and clamped to 6–40.

## Use cases

- Clinicians and trainees reviewing how creatinine, bilirubin, INR, sodium, and dialysis status affect MELD-Na.
- Researchers reproducing the stated UNOS/OPTN MELD-Na calculation with capped laboratory inputs.
- Educational comparisons of a base MELD(i) with cases where hyponatremia adds a sodium adjustment.

## Frequently asked questions

### What inputs are required?

Serum creatinine, total bilirubin, INR, and serum sodium are required. Dialysis status is optional.

### How is dialysis handled?

When selected, creatinine is set to 4.0 mg/dL before calculating the score.

### When does sodium affect the score?

Sodium affects MELD-Na when MELD(i) is above 11. If MELD(i) is 11 or lower, no sodium adjustment is applied.

### What sodium range is used?

Sodium is clamped to 125–137 mmol/L for the MELD-Na adjustment.

### Is this a current transplant allocation score or medical advice?

It calculates the specified historical UNOS/OPTN MELD-Na method. It is not medical advice, and US adult allocation now uses MELD 3.0.

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