MELD-Na (including sodium) Calculator

MELD-Na (Model for End-Stage Liver Disease including serum sodium): explanation and clinical context The MELD score is a widely validated, laboratory-based model to estimate short-term (90-day) mortality in patients with advanced liver disease; it uses serum bilirubin, INR, and serum creatinine as inputs. The MELD-Na score augments MELD by incorporating serum sodium as an independent predictor of mortality in cirrhosis, improving short-term risk discrimination and allocation priority decisions. In practical implementation the MELD is calculated using natural logarithms of bilirubin, INR, and creatinine with an intercept term; the continuous MELD value is then used in the MELD-Na adjustment.

In the widely adopted formulation derived and validated by Kim et al. (NEJM 2008), serum sodium is bounded (commonly between 125 and 140 mmol/L) before incorporation, and the MELD-Na formula used in this tool is: MELD-Na = MELD − Na − 0.025 × MELD × (140 − Na) + 140. This produces a score with improved sensitivity for short-term mortality compared with MELD alone and has been implemented in allocation policy (OPTN/UNOS) and many clinical calculators. Clinicians should note local policy differences (some sites/registries use slightly different algebraic variants or caps) and that dialysis status (dialysis twice in past 7 days or 24-hr CVVHD) may be handled by substituting a fixed creatinine per allocation rules (e.g., creatinine set to 4.0 mg/dL in those circumstances).

Use MELD and MELD-Na as part of a broader clinical assessment; they are prognostic, not prescriptive.