Emergency · LIVE

SIPA (pediatric age-adjusted shock index)

SIPA

Compute Acker 2015 SIPA as heart rate in bpm divided by cuff systolic pressure in mm Hg, then compare the ratio with the published age-band cutoff.

LIVE $0.005 USDC GET /api/calc/sipa

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

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

What it computes

Compute Acker 2015 SIPA as heart rate in bpm divided by cuff systolic pressure in mm Hg, then compare the ratio with the published age-band cutoff.

When to use

When an agent has caller-assigned age (4-16 years), heart rate, and systolic pressure and needs the published pediatric age-adjusted shock-index ratio and elevated flag.

When not to use

• Not a diagnosis of shock and not a medical device. magent does not measure heart rate or blood pressure; the caller assigns the numbers.
• Not the adult shock-index cutoff of greater than 0.9. Acker 2015 SIPA uses age-adjusted cutoffs: greater than 1.22 (ages 4-6), greater than 1.0 (ages 7-12), and greater than 0.9 (ages 13-16).
• Do not apply SIPA to infants or to adults 17 years and older. The published cohort is ages 4-16 inclusive.

Formula

sipa = heart_rate_bpm / systolic_mm_hg; elevated iff sipa > cutoff (Acker 2015: age 4-6 → 1.22, 7-12 → 1.0, 13-16 → 0.9)

Citation

Title

Pediatric specific shock index accurately identifies severely injured children

Authors

Acker SN, Ross JT, Partrick DA, Tong S, Bensard DD

Source

J Pediatr Surg. 2015;50(2):331-334

DOI

10.1016/j.jpedsurg.2014.08.009

Worked example

Also searched as

• SIPA
• pediatric shock index
• shock index pediatric age-adjusted
• Acker SIPA
• age-adjusted shock index
• pediatric SI
• HR over SBP children
• pediatric age-adjusted SI

Try

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

/api/calc/sipa?age=10&heart_rate_bpm=80&systolic_mm_hg=100

Full URL: https://api.magentlab.com/api/calc/sipa?age=10&heart_rate_bpm=80&systolic_mm_hg=100

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/sipa?age=10&heart_rate_bpm=80&systolic_mm_hg=100"

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/sipa 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": "10",
      "heart_rate_bpm": "80",
      "systolic_mm_hg": "100"
    },
    {
      "age": "10",
      "heart_rate_bpm": "80",
      "systolic_mm_hg": "100"
    }
  ]
}

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/sipa",
  "items": [
    {
      "age": 10,
      "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": "Acker SN, Ross JT, Partrick DA, Tong S, Bensard DD",
        "doi": "10.1016/j.jpedsurg.2014.08.009",
        "id": "acker-2015",
        "pmid": "25638631",
        "source": "J Pediatr Surg. 2015;50(2):331-334",
        "title": "Pediatric specific shock index accurately identifies severely injured children"
      },
      "formula": "sipa",
      "formula_expression": "sipa = heart_rate_bpm / systolic_mm_hg; elevated iff sipa > cutoff (Acker 2015: age 4-6 → 1.22, 7-12 → 1.0, 13-16 → 0.9)",
      "systolic_mm_hg": 100.0,
      "heart_rate_bpm": 80,
      "criteria": [
        {
          "value": 1.22,
          "factor": "age_4_6",
          "met": false
        },
        {
          "value": 1.0,
          "factor": "age_7_12",
          "met": true
        },
        {
          "value": 0.9,
          "factor": "age_13_16",
          "met": false
        }
      ],
      "cutoff": 1.0,
      "elevated": false,
      "sipa": 0.8
    },
    {
      "age": 10,
      "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": "Acker SN, Ross JT, Partrick DA, Tong S, Bensard DD",
        "doi": "10.1016/j.jpedsurg.2014.08.009",
        "id": "acker-2015",
        "pmid": "25638631",
        "source": "J Pediatr Surg. 2015;50(2):331-334",
        "title": "Pediatric specific shock index accurately identifies severely injured children"
      },
      "formula": "sipa",
      "formula_expression": "sipa = heart_rate_bpm / systolic_mm_hg; elevated iff sipa > cutoff (Acker 2015: age 4-6 → 1.22, 7-12 → 1.0, 13-16 → 0.9)",
      "systolic_mm_hg": 100.0,
      "heart_rate_bpm": 80,
      "criteria": [
        {
          "value": 1.22,
          "factor": "age_4_6",
          "met": false
        },
        {
          "value": 1.0,
          "factor": "age_7_12",
          "met": true
        },
        {
          "value": 0.9,
          "factor": "age_13_16",
          "met": false
        }
      ],
      "cutoff": 1.0,
      "elevated": false,
      "sipa": 0.8
    }
  ]
}

Response

Example JSON

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

{
  "age": 10,
  "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": "Acker SN, Ross JT, Partrick DA, Tong S, Bensard DD",
    "doi": "10.1016/j.jpedsurg.2014.08.009",
    "id": "acker-2015",
    "pmid": "25638631",
    "source": "J Pediatr Surg. 2015;50(2):331-334",
    "title": "Pediatric specific shock index accurately identifies severely injured children"
  },
  "formula": "sipa",
  "formula_expression": "sipa = heart_rate_bpm / systolic_mm_hg; elevated iff sipa > cutoff (Acker 2015: age 4-6 → 1.22, 7-12 → 1.0, 13-16 → 0.9)",
  "systolic_mm_hg": 100.0,
  "heart_rate_bpm": 80,
  "criteria": [
    {
      "value": 1.22,
      "factor": "age_4_6",
      "met": false
    },
    {
      "value": 1.0,
      "factor": "age_7_12",
      "met": true
    },
    {
      "value": 0.9,
      "factor": "age_13_16",
      "met": false
    }
  ],
  "cutoff": 1.0,
  "elevated": false,
  "sipa": 0.8
}

Client errors (HTTP 400)

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

Related tools

• Shock index — Compute the Allgöwer–Burri shock index as heart rate in bpm divided by cuff systolic pressure in mm Hg.
• PECARN pediatric IAI — Apply the Holmes 2013 PECARN seven-variable prediction rule and return whether the child is at very low risk of intra-abdominal injury requiring acute intervention (all seven caller-assigned findings absent). Does not order a CT.

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.