# ABC score (assessment of blood consumption)

ABC score

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/abc_score`
HTML: https://magentlab.com/docs/abc-score
Markdown: https://magentlab.com/docs/abc-score.md

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

## What it computes

Sum the four Nunez 2009 ABC (assessment of blood consumption) arrival factors and return score_ge_2 at the published ≥2 cutoff.

## When to use

When an agent needs the published Nunez 2009 ABC point total and the ≥2 cutoff flag and must not invent an MTP activation or transfusion order.

## When not to use

- Not a medical device and not a massive-transfusion protocol (MTP) or transfusion order. magent does not decide whether to activate MTP.
- ABC ≥2 was 75% sensitive and 86% specific for massive transfusion in Nunez 2009; score_ge_2 is that published classification cutoff, not an order.
- Penetrating mechanism and positive FAST are caller-assigned. magent does not interpret FAST images or assign injury mechanism.
- This is Nunez 2009 ABC only. It is not TASH, not ABC/2 ICH volume, and not a blood-product volume estimate.

## Formula

```
ABC = penetrating + sbp_le_90 + hr_ge_120 + positive_fast; each 1; max 4; score_ge_2 iff score >= 2
```

## Citation

[Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)?](https://doi.org/10.1097/TA.0b013e3181961c35)
Nunez TC, Voskresensky IV, Dossett LA, Shinall R, Dutton WD, Cotton BA
J Trauma. 2009;66(2):346-352
DOI: [10.1097/TA.0b013e3181961c35](https://doi.org/10.1097/TA.0b013e3181961c35)

## Worked example

### No factors

Given: `heart_rate_bpm=80, penetrating=false, positive_fast=false, systolic_mm_hg=120`

1. score = 0
2. score_ge_2 = false


### Penetrating mechanism and positive FAST

Given: `heart_rate_bpm=80, penetrating=true, positive_fast=true, systolic_mm_hg=120`

1. penetrating → 1; FAST → 1
2. score = 2
3. score_ge_2 = true


## Also searched as

- ABC score
- assessment of blood consumption
- Nunez ABC
- trauma ABC score
- ABC massive transfusion
- FAST ABC score

## Parameters

- `penetrating` (boolean, required): Penetrating injury mechanism as assigned by the caller (Nunez 2009). true or false. magent does not assign mechanism.
- `systolic_mm_hg` (integer, required): Arrival systolic blood pressure in mm Hg (integer 0-300). ≤90 scores 1.
- `heart_rate_bpm` (integer, required): Arrival heart rate in beats per minute (integer 30-220). ≥120 scores 1.
- `positive_fast` (boolean, required): Positive FAST as assigned by the caller (Nunez 2009). true or false. magent does not interpret FAST images.

## Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/abc_score`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
- 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": [
    {
      "heart_rate_bpm": "80",
      "penetrating": "false",
      "positive_fast": "false",
      "systolic_mm_hg": "120"
    },
    {
      "heart_rate_bpm": "80",
      "penetrating": "false",
      "positive_fast": "false",
      "systolic_mm_hg": "120"
    }
  ]
}
```

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

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/abc_score",
  "items": [
    {
      "components": [
        {
          "factor": "penetrating",
          "points": 0,
          "present": false
        },
        {
          "value": 120,
          "factor": "sbp_le_90",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "hr_ge_120",
          "points": 0,
          "present": false
        },
        {
          "factor": "positive_fast",
          "points": 0,
          "present": false
        }
      ],
      "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": "Nunez TC, Voskresensky IV, Dossett LA, Shinall R, Dutton WD, Cotton BA",
        "doi": "10.1097/TA.0b013e3181961c35",
        "id": "nunez-2009",
        "pmid": "19204506",
        "source": "J Trauma. 2009;66(2):346-352",
        "title": "Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)?"
      },
      "formula": "abc_score",
      "formula_expression": "ABC = penetrating + sbp_le_90 + hr_ge_120 + positive_fast; each 1; max 4; score_ge_2 iff score >= 2",
      "max_score": 4,
      "score": 0,
      "score_ge_2": false
    },
    {
      "components": [
        {
          "factor": "penetrating",
          "points": 0,
          "present": false
        },
        {
          "value": 120,
          "factor": "sbp_le_90",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "hr_ge_120",
          "points": 0,
          "present": false
        },
        {
          "factor": "positive_fast",
          "points": 0,
          "present": false
        }
      ],
      "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": "Nunez TC, Voskresensky IV, Dossett LA, Shinall R, Dutton WD, Cotton BA",
        "doi": "10.1097/TA.0b013e3181961c35",
        "id": "nunez-2009",
        "pmid": "19204506",
        "source": "J Trauma. 2009;66(2):346-352",
        "title": "Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)?"
      },
      "formula": "abc_score",
      "formula_expression": "ABC = penetrating + sbp_le_90 + hr_ge_120 + positive_fast; each 1; max 4; score_ge_2 iff score >= 2",
      "max_score": 4,
      "score": 0,
      "score_ge_2": false
    }
  ]
}
```

## Response fields

- `formula` (string): abc_score
- `formula_expression` (string): Exact expression used
- `score` (integer): ABC points 0-4
- `max_score` (integer): 4
- `score_ge_2` (boolean): true when score ≥2. Nunez 2009 classified that cutoff 75% sensitive / 86% specific for massive transfusion. Not an MTP order.
- `components` (array): Per-factor points
- `citation` (object): Nunez et al. J Trauma 2009 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "factor": "penetrating",
      "points": 0,
      "present": false
    },
    {
      "value": 120,
      "factor": "sbp_le_90",
      "points": 0,
      "present": false
    },
    {
      "value": 80,
      "factor": "hr_ge_120",
      "points": 0,
      "present": false
    },
    {
      "factor": "positive_fast",
      "points": 0,
      "present": false
    }
  ],
  "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": "Nunez TC, Voskresensky IV, Dossett LA, Shinall R, Dutton WD, Cotton BA",
    "doi": "10.1097/TA.0b013e3181961c35",
    "id": "nunez-2009",
    "pmid": "19204506",
    "source": "J Trauma. 2009;66(2):346-352",
    "title": "Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)?"
  },
  "formula": "abc_score",
  "formula_expression": "ABC = penetrating + sbp_le_90 + hr_ge_120 + positive_fast; each 1; max 4; score_ge_2 iff score >= 2",
  "max_score": 4,
  "score": 0,
  "score_ge_2": false
}
```

## Errors

- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged.
- HTTP 400 `invalid_rts_systolic`: systolic_mm_hg must be an integer from 0 to 300. Returned before settlement; you are not charged.
- HTTP 400 `invalid_heart_rate`: heart_rate_bpm must be an integer from 30 to 220 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.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [ISS](https://magentlab.com/docs/iss) — Compute the Baker 1974 Injury Severity Score as the sum of squares of the three highest caller-assigned AIS body-region grades, or 75 if any region is AIS 6.
- [RTS](https://magentlab.com/docs/rts) — Compute Champion 1989 coded GCS, SBP, and respiratory-rate values, the triage T-RTS sum, and the weighted RTS used for outcome evaluation.

## Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, 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.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON echoing accepted, payload, and extensions when present).
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/docs/mcp

## Guarantees

- HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
- exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
- HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.