Emergency · LIVE

Cardiac Arrest Risk Triage (CART)

CART

Compute the Churpek 2012 Cardiac Arrest Risk Triage (CART) integer score from caller-assigned maximum respiratory rate, maximum heart rate, minimum diastolic blood pressure, and age.

LIVE $0.005 USDC GET /api/calc/cart

Markdown: /docs/cart.md · Canonical: https://magentlab.com/docs/cart

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

What it computes

Compute the Churpek 2012 Cardiac Arrest Risk Triage (CART) integer score from caller-assigned maximum respiratory rate, maximum heart rate, minimum diastolic blood pressure, and age.

When to use

When an agent needs the published Churpek 2012 Table 3 CART point total and must not invent a cardiac-arrest diagnosis, RRT order, or risk-band percents.

When not to use

• Not a medical device and not a cardiac-arrest diagnosis, RRT activation, or code-blue order. magent does not measure vitals; the caller assigns maximum RR, maximum HR, minimum DBP, and age.
• Churpek 2012 Table 3 integer CART (beta x 9) only. Score range 0-57. Does not return risk-band percents or a three-band enum.
• The paper's operational cut-off for comparison with MEWS is not emitted as a required band or RRT threshold.
• This is not MEWS. Related MEWS is a different published score.

Formula

CART = rr_points + hr_points + dbp_points + age_points; Churpek 2012 Table 3 integer score (beta x 9); max 57

Citation

Title

Derivation of a Cardiac Arrest Prediction Model Using Ward Vital Signs

Authors

Churpek MM, Yuen TC, Park SY, Meltzer DO, Hall JB, Edelson DP

Source

Crit Care Med. 2012;40(7):2102-2108

DOI

10.1097/CCM.0b013e318250aa5a

Worked example

Also searched as

• cardiac arrest risk triage
• CART score
• CART
• Churpek CART
• ward vital signs cardiac arrest
• cardiac arrest triage score

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/cart?respiratory_rate=20&heart_rate_bpm=80&diastolic_mm_hg=80&age=40

Full URL: https://api.magentlab.com/api/calc/cart?respiratory_rate=20&heart_rate_bpm=80&diastolic_mm_hg=80&age=40

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/cart?respiratory_rate=20&heart_rate_bpm=80&diastolic_mm_hg=80&age=40"

Parameters

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.

POST /api/calc/cart Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 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 (fixture)

{
  "items": [
    {
      "age": "40",
      "diastolic_mm_hg": "80",
      "heart_rate_bpm": "80",
      "respiratory_rate": "20"
    },
    {
      "age": "40",
      "diastolic_mm_hg": "80",
      "heart_rate_bpm": "80",
      "respiratory_rate": "20"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/cart",
  "items": [
    {
      "components": [
        {
          "value": 20,
          "factor": "respiratory_rate",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "heart_rate_bpm",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "diastolic_mm_hg",
          "points": 0,
          "present": false
        },
        {
          "value": 40,
          "factor": "age",
          "points": 0,
          "present": false
        }
      ],
      "age": 40,
      "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": "Churpek MM, Yuen TC, Park SY, Meltzer DO, Hall JB, Edelson DP",
        "doi": "10.1097/CCM.0b013e318250aa5a",
        "id": "churpek-2012",
        "pmid": "22584764",
        "source": "Crit Care Med. 2012;40(7):2102-2108",
        "title": "Derivation of a Cardiac Arrest Prediction Model Using Ward Vital Signs"
      },
      "formula": "cart",
      "formula_expression": "CART = rr_points + hr_points + dbp_points + age_points; Churpek 2012 Table 3 integer score (beta x 9); max 57",
      "diastolic_mm_hg": 80,
      "max_score": 57,
      "score": 0,
      "heart_rate_bpm": 80,
      "respiratory_rate": 20
    },
    {
      "components": [
        {
          "value": 20,
          "factor": "respiratory_rate",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "heart_rate_bpm",
          "points": 0,
          "present": false
        },
        {
          "value": 80,
          "factor": "diastolic_mm_hg",
          "points": 0,
          "present": false
        },
        {
          "value": 40,
          "factor": "age",
          "points": 0,
          "present": false
        }
      ],
      "age": 40,
      "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": "Churpek MM, Yuen TC, Park SY, Meltzer DO, Hall JB, Edelson DP",
        "doi": "10.1097/CCM.0b013e318250aa5a",
        "id": "churpek-2012",
        "pmid": "22584764",
        "source": "Crit Care Med. 2012;40(7):2102-2108",
        "title": "Derivation of a Cardiac Arrest Prediction Model Using Ward Vital Signs"
      },
      "formula": "cart",
      "formula_expression": "CART = rr_points + hr_points + dbp_points + age_points; Churpek 2012 Table 3 integer score (beta x 9); max 57",
      "diastolic_mm_hg": 80,
      "max_score": 57,
      "score": 0,
      "heart_rate_bpm": 80,
      "respiratory_rate": 20
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "value": 20,
      "factor": "respiratory_rate",
      "points": 0,
      "present": false
    },
    {
      "value": 80,
      "factor": "heart_rate_bpm",
      "points": 0,
      "present": false
    },
    {
      "value": 80,
      "factor": "diastolic_mm_hg",
      "points": 0,
      "present": false
    },
    {
      "value": 40,
      "factor": "age",
      "points": 0,
      "present": false
    }
  ],
  "age": 40,
  "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": "Churpek MM, Yuen TC, Park SY, Meltzer DO, Hall JB, Edelson DP",
    "doi": "10.1097/CCM.0b013e318250aa5a",
    "id": "churpek-2012",
    "pmid": "22584764",
    "source": "Crit Care Med. 2012;40(7):2102-2108",
    "title": "Derivation of a Cardiac Arrest Prediction Model Using Ward Vital Signs"
  },
  "formula": "cart",
  "formula_expression": "CART = rr_points + hr_points + dbp_points + age_points; Churpek 2012 Table 3 integer score (beta x 9); max 57",
  "diastolic_mm_hg": 80,
  "max_score": 57,
  "score": 0,
  "heart_rate_bpm": 80,
  "respiratory_rate": 20
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• MEWS — Compute the Subbe 2001 modified Early Warning Score from systolic BP, heart rate, respiratory rate, temperature, and caller-assigned AVPU.

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. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /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. HTTP 402 never includes the tool JSON.
• 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.