# Corrected sodium

Status: WEDGE
Price: $0.005 USDC
`GET /api/calc/corrected_sodium`
HTML: https://magentlab.com/docs/corrected-sodium
Markdown: https://magentlab.com/docs/corrected-sodium.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Compute expected sodium in hyperglycemia using Katz 1.6 or Hillier 2.4. The formula argument is required.

## When to use

When an agent must not apply a Katz or Hillier factor silently. Callers must choose formula=katz or formula=hillier.

## When not to use

- Not a treatment recommendation and not a diagnosis of hyponatremia.
- formula is required. magent does not pick Katz or Hillier.
- Does not recommend fluid or insulin therapy. Arithmetic only for the chosen published factor.

## Formula

```
corrected_na_mmol_l = sodium_mmol_l + 1.6 * (glucose_mg_dl - 100) / 100
```

## Citation

Hyperglycemia-induced hyponatremia — calculation of expected serum sodium depression
Katz MA
N Engl J Med. 1973;289(16):843-844
DOI: [10.1056/NEJM197310182891607](https://doi.org/10.1056/NEJM197310182891607)

## Worked example

### Na 125, glucose 400, Katz

Given: `formula=katz, glucose_mg_dl=400, sodium_mmol_l=125`

1. excess = (400 - 100) / 100 = 3.0
2. corrected Na = 125 + 1.6 * 3.0 = 129.8 mmol/L


## Parameters

- `sodium_mmol_l` (number, required): Measured serum sodium in mmol/L (110-160).
- `glucose_mg_dl` (number, optional): Plasma glucose in mg/dL (50-1000). Provide this or glucose_mmol_l.
- `glucose_mmol_l` (number, optional): Plasma glucose in mmol/L (2.8-55.5). Converted as mg/dL = mmol/L * 18.015.
- `formula` (string, required): Correction factor. Required; magent does not pick one silently.

## Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/corrected_sodium`
Max items: 25
Price: unit_amount * n (unit 5000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
- HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
- Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
- x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request:

```json
{
  "items": [
    {
      "formula": "katz",
      "glucose_mg_dl": "400",
      "sodium_mmol_l": "125"
    },
    {
      "formula": "katz",
      "glucose_mg_dl": "400",
      "sodium_mmol_l": "125"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/corrected-sodium

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/corrected_sodium",
  "items": [
    {
      "factor": 1.6,
      "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.",
      "citation": {
        "authors": "Katz MA",
        "doi": "10.1056/NEJM197310182891607",
        "id": "katz-1973",
        "source": "N Engl J Med. 1973;289(16):843-844",
        "title": "Hyperglycemia-induced hyponatremia — calculation of expected serum sodium depression"
      },
      "formula": "katz",
      "formula_expression": "corrected_na_mmol_l = sodium_mmol_l + 1.6 * (glucose_mg_dl - 100) / 100",
      "corrected_sodium_mmol_l": 129.8,
      "glucose_mg_dl": 400.0,
      "sodium_mmol_l": 125.0
    },
    {
      "factor": 1.6,
      "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.",
      "citation": {
        "authors": "Katz MA",
        "doi": "10.1056/NEJM197310182891607",
        "id": "katz-1973",
        "source": "N Engl J Med. 1973;289(16):843-844",
        "title": "Hyperglycemia-induced hyponatremia — calculation of expected serum sodium depression"
      },
      "formula": "katz",
      "formula_expression": "corrected_na_mmol_l = sodium_mmol_l + 1.6 * (glucose_mg_dl - 100) / 100",
      "corrected_sodium_mmol_l": 129.8,
      "glucose_mg_dl": 400.0,
      "sodium_mmol_l": 125.0
    }
  ]
}
```

## Response fields

- `formula` (string): katz or hillier
- `formula_expression` (string): Exact expression used
- `sodium_mmol_l` (number): Input sodium in mmol/L
- `glucose_mg_dl` (number): Normalized glucose in mg/dL
- `factor` (number): Published factor: 1.6 (Katz) or 2.4 (Hillier)
- `corrected_sodium_mmol_l` (number): Corrected sodium in mmol/L, 1 decimal
- `citation` (object): Katz 1973 or Hillier 1999
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "factor": 1.6,
  "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.",
  "citation": {
    "authors": "Katz MA",
    "doi": "10.1056/NEJM197310182891607",
    "id": "katz-1973",
    "source": "N Engl J Med. 1973;289(16):843-844",
    "title": "Hyperglycemia-induced hyponatremia — calculation of expected serum sodium depression"
  },
  "formula": "katz",
  "formula_expression": "corrected_na_mmol_l = sodium_mmol_l + 1.6 * (glucose_mg_dl - 100) / 100",
  "corrected_sodium_mmol_l": 129.8,
  "glucose_mg_dl": 400.0,
  "sodium_mmol_l": 125.0
}
```

## Errors

- HTTP 400 `invalid_sodium`: sodium_mmol_l must be a number from 110 to 160 Returned before settlement; you are not charged.
- HTTP 400 `invalid_glucose`: glucose_mg_dl (50-1000) or glucose_mmol_l (2.8-55.5) is required Returned before settlement; you are not charged.
- HTTP 400 `invalid_sodium_formula`: formula must be katz or hillier Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.
- HTTP 402 `payment_required`: Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
- HTTP 409 `payment_in_progress`: The same authorization nonce is already being settled; retry shortly
- HTTP 429 `rate_limited`: Too many requests from this client
- HTTP 503 `settlement_uncertain`: Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
- HTTP 503 `facilitator_unavailable`: Payment facilitator unavailable
- HTTP 503 `facilitator_misconfigured`: Payment facilitator is not configured
- HTTP 503 `facilitator_unauthorized`: Payment facilitator rejected credentials
- HTTP 503 `ledger_unavailable`: Payment ledger unavailable
- HTTP 503 `payment_unavailable`: Payment processing unavailable

## Related tools

- [Corrected calcium](https://magentlab.com/docs/corrected-calcium) — Compute Payne albumin-corrected calcium from total calcium and albumin.
- [A1C ↔ eAG](https://magentlab.com/docs/a1c-eag) — Convert A1C percent to estimated average glucose, or the reverse, using Nathan/ADAG.
- [Bicarbonate deficit](https://magentlab.com/docs/bicarbonate-deficit) — Estimate bicarbonate deficit from weight and measured plasma HCO3 using a 50 percent body-weight apparent space.

## Also searched as

- sodium correction for hyperglycemia
- Katz correction factor
- Hillier 2.4 factor
- corrected sodium glucose
- hyperglycemia hyponatremia

## Payment

Required query parameters must be present and valid. Invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s.

## Guarantees

- Invalid query parameters return HTTP 400 before settlement. You are not charged.
- Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are not persisted. Request logs store path without query.