# Bicarbonate deficit

Status: WEDGE
Price: $0.005 USDC
`GET /api/calc/bicarbonate_deficit`
HTML: https://magentlab.com/docs/bicarbonate-deficit
Markdown: https://magentlab.com/docs/bicarbonate-deficit.md

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

## What it computes

Estimate bicarbonate deficit from weight and measured plasma HCO3 using a 50 percent body-weight apparent space.

## When to use

When an agent needs Adrogué–Madias deficit arithmetic and must not invent a bicarbonate space or replacement amount.

## When not to use

- Not a treatment order and not a bicarbonate dosing protocol. The paper uses 50 percent of body weight only as a starting space and a safety target near 8–10 mmol/L, not full correction to 24.
- Apparent space can reach 100 percent of body weight or more in extreme acidemia. This tool does not switch space with HCO3, ongoing acid production, or ventilation.

## Formula

```
bicarbonate_space_L = 0.5 * weight_kg; deficit_mEq = bicarbonate_space_L * (desired_hco3 - measured_hco3)
```

## Citation

Management of life-threatening acid-base disorders. First of two parts
Adrogué HJ, Madias NE
N Engl J Med. 1998;338(1):26-34
DOI: [10.1056/NEJM199801013380106](https://doi.org/10.1056/NEJM199801013380106)

## Worked example

### 70 kg, HCO3 4 to 8 mmol/L

Given: `bicarbonate_mmol_l=4, desired_hco3_mmol_l=8, weight_kg=70`

1. space = 0.5 × 70 = 35 L (paper starting space, 50 percent of body weight)
2. deficit = 35 × (8 − 4) = 140 mEq


## Parameters

- `weight_kg` (number, optional): Weight in kilograms. Provide weight_kg or weight_lb.
- `weight_lb` (number, optional): Weight in pounds. Converted as kg = lb * 0.45359237.
- `bicarbonate_mmol_l` (number, required): Measured plasma bicarbonate in mmol/L (same as mEq/L). Range 2-45.
- `desired_hco3_mmol_l` (number, optional): Target plasma bicarbonate in mmol/L (8-30), must exceed measured HCO3. Omitted uses 24.

## 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/bicarbonate_deficit`
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": [
    {
      "bicarbonate_mmol_l": "4",
      "desired_hco3_mmol_l": "8",
      "weight_kg": "70"
    },
    {
      "bicarbonate_mmol_l": "4",
      "desired_hco3_mmol_l": "8",
      "weight_kg": "70"
    }
  ]
}
```

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

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/bicarbonate_deficit",
  "items": [
    {
      "weight_kg": 70.0,
      "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.",
      "bicarbonate_mmol_l": 4.0,
      "bicarbonate_space_l": 35.0,
      "citation": {
        "authors": "Adrogué HJ, Madias NE",
        "doi": "10.1056/NEJM199801013380106",
        "id": "adrogue-madias-1998",
        "source": "N Engl J Med. 1998;338(1):26-34",
        "title": "Management of life-threatening acid-base disorders. First of two parts"
      },
      "deficit_meq": 140.0,
      "desired_hco3_mmol_l": 8.0,
      "formula": "adrogue_madias",
      "formula_expression": "bicarbonate_space_L = 0.5 * weight_kg; deficit_mEq = bicarbonate_space_L * (desired_hco3 - measured_hco3)"
    },
    {
      "weight_kg": 70.0,
      "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.",
      "bicarbonate_mmol_l": 4.0,
      "bicarbonate_space_l": 35.0,
      "citation": {
        "authors": "Adrogué HJ, Madias NE",
        "doi": "10.1056/NEJM199801013380106",
        "id": "adrogue-madias-1998",
        "source": "N Engl J Med. 1998;338(1):26-34",
        "title": "Management of life-threatening acid-base disorders. First of two parts"
      },
      "deficit_meq": 140.0,
      "desired_hco3_mmol_l": 8.0,
      "formula": "adrogue_madias",
      "formula_expression": "bicarbonate_space_L = 0.5 * weight_kg; deficit_mEq = bicarbonate_space_L * (desired_hco3 - measured_hco3)"
    }
  ]
}
```

## Response fields

- `formula` (string): adrogue_madias
- `formula_expression` (string): Exact expression used
- `weight_kg` (number): Normalized weight in kg
- `bicarbonate_mmol_l` (number): Measured plasma bicarbonate used
- `desired_hco3_mmol_l` (number): Target plasma bicarbonate (24 when omitted)
- `bicarbonate_space_l` (number): Apparent bicarbonate space, 0.5 * weight_kg, 1 decimal
- `deficit_meq` (number): Estimated bicarbonate deficit in mEq (mmol), 1 decimal
- `citation` (object): Adrogué and Madias NEJM 1998 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "weight_kg": 70.0,
  "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.",
  "bicarbonate_mmol_l": 4.0,
  "bicarbonate_space_l": 35.0,
  "citation": {
    "authors": "Adrogué HJ, Madias NE",
    "doi": "10.1056/NEJM199801013380106",
    "id": "adrogue-madias-1998",
    "source": "N Engl J Med. 1998;338(1):26-34",
    "title": "Management of life-threatening acid-base disorders. First of two parts"
  },
  "deficit_meq": 140.0,
  "desired_hco3_mmol_l": 8.0,
  "formula": "adrogue_madias",
  "formula_expression": "bicarbonate_space_L = 0.5 * weight_kg; deficit_mEq = bicarbonate_space_L * (desired_hco3 - measured_hco3)"
}
```

## Errors

- HTTP 400 `invalid_weight`: weight_kg (1-500) or weight_lb (2-1100) is required Returned before settlement; you are not charged.
- HTTP 400 `invalid_bicarbonate`: bicarbonate_mmol_l must be a number from 2 to 45. Returned before settlement; you are not charged.
- HTTP 400 `invalid_desired_bicarbonate`: desired_hco3_mmol_l must be a number from 8 to 30 greater than bicarbonate_mmol_l. 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

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## Also searched as

- bicarbonate deficit
- HCO3 deficit
- Adrogue Madias bicarbonate
- bicarb replacement estimate

## 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.