Emergency · LIVE

HEAVEN criteria

HEAVEN

Apply the Davis 2017 HEAVEN criteria from six caller-assigned flags and return high_risk iff any is true, plus the count of criteria met (0-6).

LIVE $0.005 USDC GET /api/calc/heaven

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

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

What it computes

Apply the Davis 2017 HEAVEN criteria from six caller-assigned flags and return high_risk iff any is true, plus the count of criteria met (0-6).

When to use

When an agent already has the six Davis 2017 HEAVEN flags (hypoxemia, extremes of size, anatomic challenges, vomit/blood/fluid, exsanguination, limited neck mobility) and needs whether any published difficult-airway criterion is present. magent does not measure SpO2 or examine the airway.

When not to use

• Not a medical device.
• Not an intubation order.
• magent does not measure SpO2 or examine the airway. The caller assigns the six flags.
• Not Mallampati, not EGRI.

Formula

high_risk iff hypoxemia or extremes_of_size or anatomic_challenges or vomit_blood_fluid or exsanguination or neck_mobility_limited; low_risk iff not high_risk; criteria_met is the count of those six flags that are true (Davis 2017 HEAVEN; high_risk iff any of six caller-assigned flags)

Citation

Title

HEAVEN Criteria: Derivation of a New Difficult Airway Prediction Tool

Authors

Davis DP, Olvera DJ

Source

Air Med J. 2017;36(4):195-197

DOI

10.1016/j.amj.2017.04.001

Worked example

Also searched as

• HEAVEN criteria
• HEAVEN airway
• Davis 2017 HEAVEN
• difficult airway HEAVEN
• first-attempt intubation failure
• air medical HEAVEN criteria
• HEAVEN RSI
• difficult laryngoscopy HEAVEN

Try

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

/api/calc/heaven?hypoxemia=false&extremes_of_size=false&anatomic_challenges=false&vomit_blood_fluid=false&exsanguination=false&neck_mobility_limited=false

Full URL: https://api.magentlab.com/api/calc/heaven?hypoxemia=false&extremes_of_size=false&anatomic_challenges=false&vomit_blood_fluid=false&exsanguination=false&neck_mobility_limited=false

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/heaven?hypoxemia=false&extremes_of_size=false&anatomic_challenges=false&vomit_blood_fluid=false&exsanguination=false&neck_mobility_limited=false"

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/heaven 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": [
    {
      "anatomic_challenges": "false",
      "exsanguination": "false",
      "extremes_of_size": "false",
      "hypoxemia": "false",
      "neck_mobility_limited": "false",
      "vomit_blood_fluid": "false"
    },
    {
      "anatomic_challenges": "false",
      "exsanguination": "false",
      "extremes_of_size": "false",
      "hypoxemia": "false",
      "neck_mobility_limited": "false",
      "vomit_blood_fluid": "false"
    }
  ]
}

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/heaven",
  "items": [
    {
      "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": "Davis DP, Olvera DJ",
        "doi": "10.1016/j.amj.2017.04.001",
        "id": "davis-2017",
        "pmid": "28739243",
        "source": "Air Med J. 2017;36(4):195-197",
        "title": "HEAVEN Criteria: Derivation of a New Difficult Airway Prediction Tool"
      },
      "formula": "heaven",
      "formula_expression": "high_risk iff hypoxemia or extremes_of_size or anatomic_challenges or vomit_blood_fluid or exsanguination or neck_mobility_limited; low_risk iff not high_risk; criteria_met is the count of those six flags that are true (Davis 2017 HEAVEN; high_risk iff any of six caller-assigned flags)",
      "criteria": [
        {
          "factor": "hypoxemia",
          "met": false
        },
        {
          "factor": "extremes_of_size",
          "met": false
        },
        {
          "factor": "anatomic_challenges",
          "met": false
        },
        {
          "factor": "vomit_blood_fluid",
          "met": false
        },
        {
          "factor": "exsanguination",
          "met": false
        },
        {
          "factor": "neck_mobility_limited",
          "met": false
        },
        {
          "factor": "high_risk_any",
          "met": false
        }
      ],
      "high_risk": false,
      "low_risk": true,
      "criteria_met": 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.",
      "citation": {
        "authors": "Davis DP, Olvera DJ",
        "doi": "10.1016/j.amj.2017.04.001",
        "id": "davis-2017",
        "pmid": "28739243",
        "source": "Air Med J. 2017;36(4):195-197",
        "title": "HEAVEN Criteria: Derivation of a New Difficult Airway Prediction Tool"
      },
      "formula": "heaven",
      "formula_expression": "high_risk iff hypoxemia or extremes_of_size or anatomic_challenges or vomit_blood_fluid or exsanguination or neck_mobility_limited; low_risk iff not high_risk; criteria_met is the count of those six flags that are true (Davis 2017 HEAVEN; high_risk iff any of six caller-assigned flags)",
      "criteria": [
        {
          "factor": "hypoxemia",
          "met": false
        },
        {
          "factor": "extremes_of_size",
          "met": false
        },
        {
          "factor": "anatomic_challenges",
          "met": false
        },
        {
          "factor": "vomit_blood_fluid",
          "met": false
        },
        {
          "factor": "exsanguination",
          "met": false
        },
        {
          "factor": "neck_mobility_limited",
          "met": false
        },
        {
          "factor": "high_risk_any",
          "met": false
        }
      ],
      "high_risk": false,
      "low_risk": true,
      "criteria_met": 0
    }
  ]
}

Response

Example JSON

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

{
  "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": "Davis DP, Olvera DJ",
    "doi": "10.1016/j.amj.2017.04.001",
    "id": "davis-2017",
    "pmid": "28739243",
    "source": "Air Med J. 2017;36(4):195-197",
    "title": "HEAVEN Criteria: Derivation of a New Difficult Airway Prediction Tool"
  },
  "formula": "heaven",
  "formula_expression": "high_risk iff hypoxemia or extremes_of_size or anatomic_challenges or vomit_blood_fluid or exsanguination or neck_mobility_limited; low_risk iff not high_risk; criteria_met is the count of those six flags that are true (Davis 2017 HEAVEN; high_risk iff any of six caller-assigned flags)",
  "criteria": [
    {
      "factor": "hypoxemia",
      "met": false
    },
    {
      "factor": "extremes_of_size",
      "met": false
    },
    {
      "factor": "anatomic_challenges",
      "met": false
    },
    {
      "factor": "vomit_blood_fluid",
      "met": false
    },
    {
      "factor": "exsanguination",
      "met": false
    },
    {
      "factor": "neck_mobility_limited",
      "met": false
    },
    {
      "factor": "high_risk_any",
      "met": false
    }
  ],
  "high_risk": false,
  "low_risk": true,
  "criteria_met": 0
}

Client errors (HTTP 400)

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

Related tools

• Mallampati — Return the Samsoon 1987 modified Mallampati class 1-4 from a caller-assigned integer, with a stable label.
• EGRI — Sum the El-Ganzouri 1996 simplified airway risk index (seven 0/1/2 items; max 12) and return high_risk when the score is 4 or more.
• Aldrete — Compute the Aldrete 1970 postanesthetic recovery score as the sum of five caller-assigned 0-2 signs (activity, respiration, circulation, consciousness, color) and return the 1970 recovery-room band.

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.