MELD-Na Score Calculator
MELD-Na Score Calculator
Calculate the sodium-adjusted MELD score used for liver allocation from 2016 until MELD 3.0 replaced it.
MELD-Na Score
5 inputs → 6–40Bilirubin 3.2, INR 1.8, creatinine 1.6, sodium 132, no dialysis
Formula
If MELD(i) > 11: MELD-Na = MELD(i) + 1.32×(137−Na) − [0.033 × MELD(i) × (137−Na)]
- creatinine
- mg/dL, bounded 1.0–4.0; set to 4.0 on dialysis
- bilirubin, INR
- floored at 1.0
- sodium
- mmol/L, bounded 125–137
- sodium adjustment
- applied only when the base MELD exceeds 11
Worked example
Bilirubin 3.2, INR 1.8, creatinine 1.6, sodium 132, no dialysis
0.957×ln(1.6)=0.450 · 0.378×ln(3.2)=0.440 · 1.120×ln(1.8)=0.658 · +0.643
Sum 2.191 × 10 = 21.91 → MELD(i) = 22
22 > 11, so add 1.32×5 − 0.033×22×5 = 6.60 − 3.63 = 2.97
22 + 2.97 = 24.97 → MELD-Na 25
Why sodium was added
| Observation | Consequence |
|---|---|
| Hyponatraemia predicts mortality independently of MELD | Patients with ascites and low sodium were under-prioritised |
| Adjustment applies only above MELD 11 | Below that, the sodium term adds noise rather than signal |
| Sodium bounded 125–137 | Prevents extreme values dominating the score |
Where MELD-Na still applies
Hyponatraemia in cirrhosis is a marker of advanced portal hypertension and impaired free water clearance, and it predicts death independently of bilirubin, creatinine and INR. Patients with refractory ascites and a low sodium were dying on waiting lists with unremarkable MELD scores, which is what prompted the sodium adjustment adopted in 2016.
The adjustment is deliberately conditional. Below a base MELD of 11 the sodium term adds noise rather than signal, so it is not applied, and sodium itself is bounded to 125–137 so that a single extreme value cannot dominate.
MELD 3.0 has replaced MELD-Na for allocation in the United States, but MELD-Na remains in wide use. Many transplant programmes outside the US still allocate on it, a great deal of published literature and trial eligibility is written in terms of it, and prognostic thresholds for procedures — TIPS, elective surgery, anticoagulation decisions — were largely derived using MELD-Na rather than its successor. It is worth being able to calculate both.
Frequently asked questions
When is the sodium adjustment applied?
Only when the base MELD score exceeds 11. At or below that, MELD-Na equals the unadjusted MELD.
Why is sodium bounded to 125 and 137?
To stop extreme values dominating. Sodium below 125 is set to 125 and above 137 to 137, so the adjustment cannot exceed a fixed contribution.
Is MELD-Na still used?
Yes. MELD 3.0 replaced it for US allocation in 2023, but many programmes elsewhere still use it, and most published thresholds for surgical risk and procedures were derived with it.
What creatinine is used on dialysis?
4.0 mg/dL, if the patient has had dialysis twice in the past week or 24 hours of CVVHD. Note this differs from MELD 3.0, which uses 3.0.
Related calculators
References
- Kim WR et al. Hyponatremia and mortality among patients on the liver-transplant waiting list. N Engl J Med. 2008;359(10):1018–26.
- OPTN/UNOS policy — MELD-Na implementation, January 2016.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.