Health

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MELD-Na score — the sodium-modified MELD used for adult liver transplant allocation in the US from January 2016 until superseded by MELD 3.0 in July 2023.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.

json· JSON resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/meld-na-score' \
  -H 'Content-Type: application/json' \
  -d '{"creatinine":1.5,"bilirubin":3,"inr":1.8,"sodium":130,"dialysis":false,"decimalPlaces":4}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/meld-na-score

Parameters

Name	Type	Required	Description
creatinine	number	Yes	Serum creatinine in mg/dL. Floored at 1.0, capped at 4.0 (4.0 if dialyzed). Must be positive.
bilirubin	number	Yes	Total bilirubin in mg/dL. Floored at 1.0. Must be positive.
inr	number	Yes	INR. Floored at 1.0. Must be positive.
sodium	number	Yes	Serum sodium in mmol/L. Clamped to 125–137 for the MELD-Na adjustment. Must be positive.
dialysis	checkbox

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-meld-na-score": {
      "name": "meld-na-score",
      "description": "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MELD-Na score — the sodium-modified MELD used for adult liver transplant allocation in the US from January 2016 until superseded by MELD 3.0 in July 2023.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.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=meld-na-score",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "meld-na-score",
    "arguments": {
  "creatinine": 1.5,
  "bilirubin": 3,
  "inr": 1.8,
  "sodium": 130,
  "dialysis": false,
  "decimalPlaces": 4
}
  }
}

Browse tools Open tool