Murray lung injury score (LIS)

Murray lung injury score

Mean the four Murray 1988 lung injury score components (chest radiograph quadrants, PaO2/FiO2, PEEP, and compliance), each 0–4, and return LIS and injury_band.

LIVE $0.005 USDC GET /api/calc/murray

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

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

What it computes

Mean the four Murray 1988 lung injury score components (chest radiograph quadrants, PaO2/FiO2, PEEP, and compliance), each 0–4, and return LIS and injury_band.

When to use

When an agent has caller-assigned chest radiograph quadrants and the three physiologic components and needs the published Murray LIS mean, not a Berlin ARDS diagnosis and not a ventilator order.

When not to use

Not a medical device.
Not a Berlin ARDS diagnosis. injury_band is Murray 1988 none / mild_moderate / severe from the LIS mean, not the Berlin definition.
Not a ventilator order. magent does not set PEEP or measure compliance.
magent does not interpret imaging; the caller assigns chest radiograph quadrants (0–4). All four components are required; missing components are not dropped.

Formula

LIS = mean of chest_radiograph_quadrants (0–4) + PaO2/FiO2 (≥300→0, 225–299→1, 175–224→2, 100–174→3, <100→4) + PEEP cm H2O (≤5→0, 6–8→1, 9–11→2, 12–14→3, ≥15→4) + compliance mL/cm H2O (≥80→0, 60–79→1, 40–59→2, 20–39→3, ≤19→4); Murray 1988; none if LIS=0, mild_moderate if 0<LIS≤2.5, severe if LIS>2.5

Citation

Title: An expanded definition of the adult respiratory distress syndrome
Authors: Murray JF, Matthay MA, Luce JM, Flick MR
Source: Am Rev Respir Dis. 1988;138(3):720-723
DOI: 10.1164/ajrccm/138.3.720

Worked example

All components 0

Given: chest_radiograph_quadrants=0compliance_ml_cm_h2o=90peep_cm_h2o=5pf_ratio=400

chest_radiograph_quadrants 0 → 0
pf_ratio 400 ≥300 → 0
peep_cm_h2o 5 ≤5 → 0
compliance_ml_cm_h2o 90 ≥80 → 0
LIS = (0+0+0+0)/4 = 0.0; injury_band none

LIS 2.5 mild_moderate

Given: chest_radiograph_quadrants=2compliance_ml_cm_h2o=20peep_cm_h2o=12pf_ratio=175

chest_radiograph_quadrants 2 → 2
pf_ratio 175 → 2
peep_cm_h2o 12 → 3
compliance_ml_cm_h2o 20 → 3
LIS = (2+2+3+3)/4 = 2.5; injury_band mild_moderate (2.5 is not severe)

Also searched as

Murray LIS
lung injury score
Murray lung injury score
LIS Murray 1988
acute lung injury score
Murray 1988 LIS

Try

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

/api/calc/murray?chest_radiograph_quadrants=0&pf_ratio=400&peep_cm_h2o=5&compliance_ml_cm_h2o=90

Full URL: https://api.magentlab.com/api/calc/murray?chest_radiograph_quadrants=0&pf_ratio=400&peep_cm_h2o=5&compliance_ml_cm_h2o=90

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/murray?chest_radiograph_quadrants=0&pf_ratio=400&peep_cm_h2o=5&compliance_ml_cm_h2o=90"

Parameters

Name	Type	Required	Description
`chest_radiograph_quadrants`	integer	required · 0, 1, 2, 3, 4	Caller-assigned alveolar consolidation quadrants 0-4 (Murray 1988). 0 none, 1 one quadrant, 2 two quadrants, 3 three quadrants, 4 four quadrants. The integer is that component's points. magent does not interpret imaging.
`pf_ratio`	number	required	PaO2/FiO2 ratio (20-800). Murray 1988: ≥300 → 0, 225-299 → 1, 175-224 → 2, 100-174 → 3, <100 → 4. magent does not read an ABG.
`peep_cm_h2o`	number	required	PEEP in cm H2O (0-40). Murray 1988: ≤5 → 0, 6-8 → 1, 9-11 → 2, 12-14 → 3, ≥15 → 4. Not a ventilator order. magent does not set PEEP.
`compliance_ml_cm_h2o`	number	required	Respiratory system compliance in mL/cm H2O (5-200). Murray 1988: ≥80 → 0, 60-79 → 1, 40-59 → 2, 20-39 → 3, ≤19 → 4. magent does not measure compliance.

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/murray 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": [
    {
      "chest_radiograph_quadrants": "0",
      "compliance_ml_cm_h2o": "90",
      "peep_cm_h2o": "5",
      "pf_ratio": "400"
    },
    {
      "chest_radiograph_quadrants": "0",
      "compliance_ml_cm_h2o": "90",
      "peep_cm_h2o": "5",
      "pf_ratio": "400"
    }
  ]
}

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/murray",
  "items": [
    {
      "components": [
        {
          "value": 0,
          "factor": "chest_radiograph_quadrants",
          "points": 0,
          "present": false
        },
        {
          "value": 400.0,
          "factor": "pf_ratio",
          "points": 0,
          "present": false
        },
        {
          "value": 5.0,
          "factor": "peep_cm_h2o",
          "points": 0,
          "present": false
        },
        {
          "value": 90.0,
          "factor": "compliance_ml_cm_h2o",
          "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": "Murray JF, Matthay MA, Luce JM, Flick MR",
        "doi": "10.1164/ajrccm/138.3.720",
        "id": "murray-1988",
        "pmid": "3202424",
        "source": "Am Rev Respir Dis. 1988;138(3):720-723",
        "title": "An expanded definition of the adult respiratory distress syndrome"
      },
      "formula": "murray",
      "formula_expression": "LIS = mean of chest_radiograph_quadrants (0–4) + PaO2/FiO2 (≥300→0, 225–299→1, 175–224→2, 100–174→3, <100→4) + PEEP cm H2O (≤5→0, 6–8→1, 9–11→2, 12–14→3, ≥15→4) + compliance mL/cm H2O (≥80→0, 60–79→1, 40–59→2, 20–39→3, ≤19→4); Murray 1988; none if LIS=0, mild_moderate if 0<LIS≤2.5, severe if LIS>2.5",
      "pf_ratio": 400.0,
      "chest_radiograph_quadrants": 0,
      "compliance_ml_cm_h2o": 90.0,
      "injury_band": "none",
      "lis": 0.0,
      "peep_cm_h2o": 5.0
    },
    {
      "components": [
        {
          "value": 0,
          "factor": "chest_radiograph_quadrants",
          "points": 0,
          "present": false
        },
        {
          "value": 400.0,
          "factor": "pf_ratio",
          "points": 0,
          "present": false
        },
        {
          "value": 5.0,
          "factor": "peep_cm_h2o",
          "points": 0,
          "present": false
        },
        {
          "value": 90.0,
          "factor": "compliance_ml_cm_h2o",
          "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": "Murray JF, Matthay MA, Luce JM, Flick MR",
        "doi": "10.1164/ajrccm/138.3.720",
        "id": "murray-1988",
        "pmid": "3202424",
        "source": "Am Rev Respir Dis. 1988;138(3):720-723",
        "title": "An expanded definition of the adult respiratory distress syndrome"
      },
      "formula": "murray",
      "formula_expression": "LIS = mean of chest_radiograph_quadrants (0–4) + PaO2/FiO2 (≥300→0, 225–299→1, 175–224→2, 100–174→3, <100→4) + PEEP cm H2O (≤5→0, 6–8→1, 9–11→2, 12–14→3, ≥15→4) + compliance mL/cm H2O (≥80→0, 60–79→1, 40–59→2, 20–39→3, ≤19→4); Murray 1988; none if LIS=0, mild_moderate if 0<LIS≤2.5, severe if LIS>2.5",
      "pf_ratio": 400.0,
      "chest_radiograph_quadrants": 0,
      "compliance_ml_cm_h2o": 90.0,
      "injury_band": "none",
      "lis": 0.0,
      "peep_cm_h2o": 5.0
    }
  ]
}

Response

Field	Type	Description
`formula`	string	murray
`formula_expression`	string	Exact expression used
`lis`	number	Murray lung injury score: mean of the four 0-4 components, 2 decimals
`injury_band`	string	Murray 1988: none if LIS=0, mild_moderate if 0<LIS≤2.5, severe if LIS>2.5. Not a Berlin ARDS diagnosis.
`chest_radiograph_quadrants`	integer	Caller-assigned quadrants 0-4 used
`pf_ratio`	number	PaO2/FiO2 used
`peep_cm_h2o`	number	PEEP in cm H2O used
`compliance_ml_cm_h2o`	number	Respiratory system compliance in mL/cm H2O used
`components`	array	Per-component Murray 1988 points
`citation`	object	Murray et al. Am Rev Respir Dis 1988 citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": 0,
      "factor": "chest_radiograph_quadrants",
      "points": 0,
      "present": false
    },
    {
      "value": 400.0,
      "factor": "pf_ratio",
      "points": 0,
      "present": false
    },
    {
      "value": 5.0,
      "factor": "peep_cm_h2o",
      "points": 0,
      "present": false
    },
    {
      "value": 90.0,
      "factor": "compliance_ml_cm_h2o",
      "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": "Murray JF, Matthay MA, Luce JM, Flick MR",
    "doi": "10.1164/ajrccm/138.3.720",
    "id": "murray-1988",
    "pmid": "3202424",
    "source": "Am Rev Respir Dis. 1988;138(3):720-723",
    "title": "An expanded definition of the adult respiratory distress syndrome"
  },
  "formula": "murray",
  "formula_expression": "LIS = mean of chest_radiograph_quadrants (0–4) + PaO2/FiO2 (≥300→0, 225–299→1, 175–224→2, 100–174→3, <100→4) + PEEP cm H2O (≤5→0, 6–8→1, 9–11→2, 12–14→3, ≥15→4) + compliance mL/cm H2O (≥80→0, 60–79→1, 40–59→2, 20–39→3, ≤19→4); Murray 1988; none if LIS=0, mild_moderate if 0<LIS≤2.5, severe if LIS>2.5",
  "pf_ratio": 400.0,
  "chest_radiograph_quadrants": 0,
  "compliance_ml_cm_h2o": 90.0,
  "injury_band": "none",
  "lis": 0.0,
  "peep_cm_h2o": 5.0
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_murray`	chest_radiograph_quadrants must be an integer 0, 1, 2, 3, or 4 (Murray 1988). Returned before settlement; you are not charged.
400	`invalid_pf_ratio`	pf_ratio must be a number from 20 to 800. Returned before settlement; you are not charged.
400	`invalid_peep_cm_h2o`	peep_cm_h2o must be a number from 0 to 40 (Murray 1988). Returned before settlement; you are not charged.
400	`invalid_compliance_ml_cm`	compliance_ml_cm_h2o must be a number from 5 to 200 (Murray 1988). Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

PaO2/FiO2 ratio — Compute the PaO2/FiO2 ratio as arterial PO2 in mm Hg divided by inspired oxygen fraction.

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.