MELD-Na Score

What This Calculator Measures

Calculates the MELD-Na score, which adds serum sodium to the MELD model to improve 3-month mortality prediction in advanced liver disease. MELD-Na is a widely used prognostic model for transplant waitlist mortality; U.S. liver allocation transitioned to the MELD 3.0 model in July 2023.

How to Use

1. Enter the most recent serum bilirubin, creatinine, INR, and sodium.
2. Indicate whether the patient has been on dialysis at least twice in the past week (creatinine is set to 4 mg/dL).
3. Serum sodium is clamped between 125 and 137 mmol/L by the model before calculation.
4. Review the score against the same mortality-risk bands used for MELD.

Interpretation Guide

MELD-Na <10 indicates low 3-month mortality risk; 10–19 moderate; 20–29 high; 30–39 very high; ≥40 extremely high risk. Sodium below 137 mmol/L raises the score because hyponatremia worsens prognosis.

Clinical Significance

MELD-Na was adopted by UNOS for liver allocation because adding serum sodium improves mortality prediction compared with MELD alone, particularly in patients with hyponatremia. U.S. liver allocation transitioned to the MELD 3.0 model in July 2023.

When to Use

• Transplant waitlist risk assessment in cirrhosis
• Prognosis in cirrhosis with hyponatremia
• Serial severity monitoring in decompensated liver disease

When Not to Use

• Acute liver failure, which is not modeled by MELD-Na
• Pediatric patients (PELD-based allocation applies)
• When serum sodium is unreliable, such as with recent aggressive diuresis or hypotonic fluid administration
• As a replacement for clinical assessment of ascites and encephalopathy

Limitations

• Sodium is clamped to a maximum of 137 mmol/L, so the score does not reward supra-normal sodium.
• Non-hepatic causes of hyponatremia (e.g., SIADH, diuretics) can bias the score.
• Retains the creatinine/INR caveats of the underlying MELD model.

Worked Example

A 60-year-old woman with cirrhosis and ascites is listed for transplant. Bilirubin is 2.5 mg/dL, creatinine 1.2 mg/dL, INR 1.5, sodium 130 mmol/L, and she is not on dialysis.

MELD ≈ 16; MELD-Na = 16 + 1.32×(137−130) − 0.033×16×(137−130) ≈ 22 — high 3-month mortality risk (band 20–29).

Evidence

Source

Original MELD-Na Description / UNOS

Reference

Kim WR, et al. Hyponatremia and mortality among patients on the liver-transplant waiting list. N Engl J Med. 2008;359:1018-1026.

Reviewed By

MedCalcHub Clinical Team

Version

1.0

Updated

2026-08

1. Kim WR, et al. N Engl J Med. 2008;359:1018-1026.

References

1. Kim WR, et al. Hyponatremia and mortality among patients on the liver-transplant waiting list. N Engl J Med. 2008;359:1018-1026. (Original model)