# MELD-Na Score Calculator (OPTN/UNOS 2016)

> MELD-Na Score Calculator (OPTN/UNOS 2016) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Calculates the OPTN/UNOS 2016 MELD-Na score from creatinine, bilirubin, INR, sodium, and dialysis status using the published deterministic formula.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/meld_na
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/meld-na-score-calculator-optn-unos-2016-08a8975d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_868n7FmMHhDVNyAn8XaPy

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability meld-na-score-calculator-optn-unos-2016-08a8975d
```

Example prompt: Calculate the MELD-Na score for a patient with an INR of 1.9, creatinine of 2.3 mg/dL, bilirubin of 4.1 mg/dL, serum sodium of 130 mmol/L, and not on dialysis.

## When to prefer this

Use this endpoint when you need a deterministic, citeable OPTN/UNOS 2016 MELD-Na score computed from raw lab values. Prefer it over manual calculation to ensure correct OPTN floor/cap/clamp rules are applied (creatinine floor at 1, cap at 4; dialysis override to 4.0; sodium clamped to 125–137 when MELD > 11). Not a transplant listing recommendation — purely a reproducible scoring computation backed by a published citation.

## Known failure modes

- Missing required parameters (INR, sodium_mmol_l, or dialysis) returns a validation error
- Out-of-range values (e.g. sodium outside 110–160, INR outside 0.8–10) may be rejected or clamped per OPTN rules
- Neither bilirubin_mg_dl nor bilirubin_umol_l provided returns an error
- Neither creatinine_mg_dl nor creatinine_umol_l provided returns an error
- Network timeout or payment failure (x402) prevents score retrieval

## How this service works

OPTN/UNOS 2016 MELD-Na from creatinine, bilirubin, INR, sodium, and dialysis. Deterministic published score with citation; not a listing recommendation.

## Output

Returns the computed MELD-Na score as a numeric value, along with intermediate values (floored/clamped inputs per OPTN rules) and the published formula citation. Includes notes on OPTN-specified floors and caps applied to inputs (e.g. creatinine floored at 1, capped at 4; sodium clamped to 125–137 range when MELD > 11).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "inr",
      "sodium_mmol_l",
      "dialysis"
     ],
     "properties": {
      "inr": {
       "type": "number",
       "description": "INR (0.8-10). OPTN floors at 1."
      },
      "dialysis": {
       "type": "boolean",
       "description": "Dialysis twice in the last week. true sets creatinine used to 4.0."
      },
      "sodium_mmol_l": {
       "type": "number",
       "description": "Serum sodium in mmol/L (110-160). OPTN clamps 125-137. Applied only when MELD > 11."
      },
      "bilirubin_mg_dl": {
       "type": "number",
       "description": "Total bilirubin in mg/dL (0.1-40). Provide this or bilirubin_umol_l. OPTN floors at 1."
      },
      "bilirubin_umol_l": {
       "type": "number",
       "description": "Total bilirubin in µmol/L. Converted as mg/dL = µmol/L / 17.1."
      },
      "creatinine_mg_dl": {
       "type": "number",
       "description": "Serum creatinine in mg/dL. Provide this or creatinine_umol_l. OPTN floors at 1 and caps at 4."
      },
      "creatinine_umol_l": {
       "type": "number",
       "description": "Serum creatinine in µmol/L."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "path": "/api/calc/meld_na",
  "count": 2,
  "items": [
   {
    "inr": 1.2,
    "meld": 20,
    "formula": "optn_meld_na_2016",
    "meld_na": 26,
    "citation": {
     "id": "optn-meld-na-2016",
     "doi": "10.1053/j.gastro.2006.02.010",
     "title": "Serum sodium predicts mortality in patients listed for liver transplantation; OPTN Policy 9 MELD-Na bounds",
     "source": "Gastroenterology. 2006;130(6):1652-1660; OPTN Policy 9 (2016)",
     "authors": "Biggins SW, Kim WR, Terrault NA, et al.; OPTN/UNOS"
    },
    "dialysis": false,
    "inr_used": 1.2,
    "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
    "sodium_mmol_l": 128,
    "bilirubin_mg_dl": 4.2,
    "creatinine_mg_dl": 1.9,
    "formula_expression": "MELD = round(10 * (0.957*ln(Cr) + 0.378*ln(bili) + 1.120*ln(INR) + 0.643)); if MELD > 11, MELD-Na = round(MELD + 1.32*(137-Na) - 0.033*MELD*(137-Na))",
    "sodium_used_mmol_l": 128,
    "bilirubin_used_mg_dl": 4.2,
    "creatinine_used_mg_dl": 1.9
   },
   {
    "inr": 1.2,
    "meld": 20,
    "formula": "optn_meld_na_2016",
    "meld_na": 26,
    "citation": {
     "id": "optn-meld-na-2016",
     "doi": "10.1053/j.gastro.2006.02.010",
     "title": "Serum sodium predicts mortality in patients listed for liver transplantation; OPTN Policy 9 MELD-Na bounds",
     "source": "Gastroenterology. 2006;130(6):1652-1660; OPTN Policy 9 (2016)",
     "authors": "Biggins SW, Kim WR, Terrault NA, et al.; OPTN/UNOS"
    },
    "dialysis": false,
    "inr_used": 1.2,
    "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
    "sodium_mmol_l": 128,
    "bilirubin_mg_dl": 4.2,
    "creatinine_mg_dl": 1.9,
    "formula_expression": "MELD = round(10 * (0.957*ln(Cr) + 0.378*ln(bili) + 1.120*ln(INR) + 0.643)); if MELD > 11, MELD-Na = round(MELD + 1.32*(137-Na) - 0.033*MELD*(137-Na))",
    "sodium_used_mmol_l": 128,
    "bilirubin_used_mg_dl": 4.2,
    "creatinine_used_mg_dl": 1.9
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/meld-na-score-calculator-optn-unos-2016-08a8975d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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