El-Ganzouri risk index (EGRI)

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.

LIVE $0.005 USDC GET /api/calc/egri

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

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

What it computes

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.

When to use

When an agent already has the seven El-Ganzouri 1996 Methods items and needs the published simplified-index total. magent does not examine the airway. Original 3-class Mallampati only; not Samsoon class IV and not HEAVEN.

When not to use

Not a medical device. magent does not examine the airway. Not an intubation order.
El-Ganzouri 1996 original 3-class Mallampati only (classes 1-3). Samsoon class IV is not used; mallampati 4 is rejected.
Not HEAVEN. The seven simplified-index items and 0/1/2 weights follow El-Ganzouri 1996 Methods. High risk is a simplified-index value of four or more (Grade IV vs Mallampati III), not an intubation order.

Formula

EGRI = mouth_opening (>4 cm: 0, <=4 cm: 1) + thyromental (>6.5 cm: 0, 6.0-6.5: 1, <6.0: 2) + mallampati (1: 0, 2: 1, 3: 2) + neck_movement (>90 deg: 0, 80-90: 1, <80: 2) + can_prognath (true: 0, false: 1) + weight (<90 kg: 0, 90-110: 1, >110: 2) + history_difficult_intubation (none: 0, questionable: 1, definite: 2); max 12; high_risk if score >= 4

Citation

Title: Preoperative airway assessment: predictive value of a multivariate risk index
Authors: el-Ganzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD
Source: Anesth Analg. 1996;82(6):1197-1204
DOI: 10.1097/00000539-199606000-00017

Worked example

All low-risk items

Given: can_prognath=truehistory_difficult_intubation=nonemallampati=1mouth_opening_cm=5neck_movement_deg=100thyromental_cm=7weight_kg=70

mouth_opening 5 >4 → 0; thyromental 7 >6.5 → 0; mallampati 1 → 0
neck 100 >90 → 0; can_prognath true → 0; weight 70 <90 → 0; history none → 0
score = 0 (max 12); high_risk false; egri_band lt_4

Mallampati 3 and definite difficult-intubation history

Given: can_prognath=truehistory_difficult_intubation=definitemallampati=3mouth_opening_cm=5neck_movement_deg=100thyromental_cm=7weight_kg=70

mallampati 3 → 2; history definite → 2; all other items 0
score = 4 (max 12); high_risk true; egri_band gte_4

Also searched as

El-Ganzouri risk index
EGRI
simplified airway risk index
El-Ganzouri 1996
airway risk index
preoperative airway assessment
difficult intubation index
multivariate airway risk

Try

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

/api/calc/egri?mouth_opening_cm=5&thyromental_cm=7&mallampati=1&neck_movement_deg=100&can_prognath=true&weight_kg=70&history_difficult_intubation=none

Full URL: https://api.magentlab.com/api/calc/egri?mouth_opening_cm=5&thyromental_cm=7&mallampati=1&neck_movement_deg=100&can_prognath=true&weight_kg=70&history_difficult_intubation=none

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/egri?mouth_opening_cm=5&thyromental_cm=7&mallampati=1&neck_movement_deg=100&can_prognath=true&weight_kg=70&history_difficult_intubation=none"

Parameters

Name	Type	Required	Description
`mouth_opening_cm`	number	required	Interincisor gap in centimetres (0.5-10) as assigned by the caller. El-Ganzouri 1996: >4 cm scores 0; <=4 cm scores 1. Exactly 4.0 scores 1. magent does not measure mouth opening.
`thyromental_cm`	number	required	Thyromental distance in centimetres (2-15) as assigned by the caller. El-Ganzouri 1996: >6.5 cm scores 0; 6.0-6.5 inclusive scores 1; <6.0 cm scores 2. Exactly 6.5 scores 1.
`mallampati`	integer	required	Original Mallampati class 1, 2, or 3 as assigned by the caller (El-Ganzouri 1996). 1 scores 0; 2 scores 1; 3 scores 2. Samsoon class 4 is not used and is rejected.
`neck_movement_deg`	number	required	Head and neck range of motion in degrees (0-180) as assigned by the caller. El-Ganzouri 1996: >90 scores 0; 80-90 inclusive scores 1; <80 scores 2. Exactly 90 scores 1. magent does not measure neck motion.
`can_prognath`	boolean	required	Ability to prognath (jaw protrusion) as assigned by the caller (El-Ganzouri 1996). true scores 0; false scores 1. true or false.
`weight_kg`	number	optional	Body weight in kilograms (1-500). Provide weight_kg or weight_lb. El-Ganzouri 1996: <90 kg scores 0; 90-110 inclusive scores 1; >110 kg scores 2. Exactly 90 and 110 score 1.
`weight_lb`	number	optional	Body weight in pounds (2-1100). Converted as kg = lb × 0.45359237, then the El-Ganzouri 1996 kg bands apply. Provide weight_kg or weight_lb.
`history_difficult_intubation`	string	required · none, questionable, definite	History of difficult intubation as assigned by the caller (El-Ganzouri 1996): none scores 0, questionable scores 1, definite scores 2.

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/egri 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": [
    {
      "can_prognath": "true",
      "history_difficult_intubation": "none",
      "mallampati": "1",
      "mouth_opening_cm": "5",
      "neck_movement_deg": "100",
      "thyromental_cm": "7",
      "weight_kg": "70"
    },
    {
      "can_prognath": "true",
      "history_difficult_intubation": "none",
      "mallampati": "1",
      "mouth_opening_cm": "5",
      "neck_movement_deg": "100",
      "thyromental_cm": "7",
      "weight_kg": "70"
    }
  ]
}

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/egri",
  "items": [
    {
      "components": [
        {
          "value": 5.0,
          "factor": "mouth_opening_cm",
          "points": 0,
          "present": false
        },
        {
          "value": 7.0,
          "factor": "thyromental_cm",
          "points": 0,
          "present": false
        },
        {
          "value": 1,
          "factor": "mallampati",
          "points": 0,
          "present": false
        },
        {
          "value": 100.0,
          "factor": "neck_movement_deg",
          "points": 0,
          "present": false
        },
        {
          "value": true,
          "factor": "can_prognath",
          "points": 0,
          "present": false
        },
        {
          "value": 70.0,
          "factor": "weight",
          "points": 0,
          "present": false
        },
        {
          "value": "none",
          "factor": "history_difficult_intubation",
          "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": "el-Ganzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD",
        "doi": "10.1097/00000539-199606000-00017",
        "id": "el-ganzouri-1996",
        "pmid": "8638791",
        "source": "Anesth Analg. 1996;82(6):1197-1204",
        "title": "Preoperative airway assessment: predictive value of a multivariate risk index"
      },
      "formula": "egri",
      "formula_expression": "EGRI = mouth_opening (>4 cm: 0, <=4 cm: 1) + thyromental (>6.5 cm: 0, 6.0-6.5: 1, <6.0: 2) + mallampati (1: 0, 2: 1, 3: 2) + neck_movement (>90 deg: 0, 80-90: 1, <80: 2) + can_prognath (true: 0, false: 1) + weight (<90 kg: 0, 90-110: 1, >110: 2) + history_difficult_intubation (none: 0, questionable: 1, definite: 2); max 12; high_risk if score >= 4",
      "max_score": 12,
      "score": 0,
      "weight_kg": 70.0,
      "high_risk": false,
      "can_prognath": true,
      "egri_band": "lt_4",
      "history_difficult_intubation": "none",
      "mallampati": 1,
      "mouth_opening_cm": 5.0,
      "neck_movement_deg": 100.0,
      "thyromental_cm": 7.0
    },
    {
      "components": [
        {
          "value": 5.0,
          "factor": "mouth_opening_cm",
          "points": 0,
          "present": false
        },
        {
          "value": 7.0,
          "factor": "thyromental_cm",
          "points": 0,
          "present": false
        },
        {
          "value": 1,
          "factor": "mallampati",
          "points": 0,
          "present": false
        },
        {
          "value": 100.0,
          "factor": "neck_movement_deg",
          "points": 0,
          "present": false
        },
        {
          "value": true,
          "factor": "can_prognath",
          "points": 0,
          "present": false
        },
        {
          "value": 70.0,
          "factor": "weight",
          "points": 0,
          "present": false
        },
        {
          "value": "none",
          "factor": "history_difficult_intubation",
          "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": "el-Ganzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD",
        "doi": "10.1097/00000539-199606000-00017",
        "id": "el-ganzouri-1996",
        "pmid": "8638791",
        "source": "Anesth Analg. 1996;82(6):1197-1204",
        "title": "Preoperative airway assessment: predictive value of a multivariate risk index"
      },
      "formula": "egri",
      "formula_expression": "EGRI = mouth_opening (>4 cm: 0, <=4 cm: 1) + thyromental (>6.5 cm: 0, 6.0-6.5: 1, <6.0: 2) + mallampati (1: 0, 2: 1, 3: 2) + neck_movement (>90 deg: 0, 80-90: 1, <80: 2) + can_prognath (true: 0, false: 1) + weight (<90 kg: 0, 90-110: 1, >110: 2) + history_difficult_intubation (none: 0, questionable: 1, definite: 2); max 12; high_risk if score >= 4",
      "max_score": 12,
      "score": 0,
      "weight_kg": 70.0,
      "high_risk": false,
      "can_prognath": true,
      "egri_band": "lt_4",
      "history_difficult_intubation": "none",
      "mallampati": 1,
      "mouth_opening_cm": 5.0,
      "neck_movement_deg": 100.0,
      "thyromental_cm": 7.0
    }
  ]
}

Response

Field	Type	Description
`formula`	string	egri
`formula_expression`	string	El-Ganzouri 1996 simplified airway risk index
`score`	integer	EGRI points 0-12
`max_score`	integer	12
`high_risk`	boolean	true iff score >= 4 (El-Ganzouri 1996 simplified index value of four for Grade IV vs Mallampati III). Not an intubation order.
`egri_band`	string	lt_4 when score < 4; gte_4 when score >= 4
`mouth_opening_cm`	number	Caller-assigned interincisor gap in centimetres
`thyromental_cm`	number	Caller-assigned thyromental distance in centimetres
`mallampati`	integer	Caller-assigned original Mallampati class 1-3
`neck_movement_deg`	number	Caller-assigned head/neck range of motion in degrees
`can_prognath`	boolean	Caller-assigned ability to prognath
`weight_kg`	number	Weight in kilograms after optional lb conversion
`history_difficult_intubation`	string	none, questionable, or definite
`components`	array	Per-factor points
`citation`	object	el-Ganzouri et al. Anesth Analg 1996 citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": 5.0,
      "factor": "mouth_opening_cm",
      "points": 0,
      "present": false
    },
    {
      "value": 7.0,
      "factor": "thyromental_cm",
      "points": 0,
      "present": false
    },
    {
      "value": 1,
      "factor": "mallampati",
      "points": 0,
      "present": false
    },
    {
      "value": 100.0,
      "factor": "neck_movement_deg",
      "points": 0,
      "present": false
    },
    {
      "value": true,
      "factor": "can_prognath",
      "points": 0,
      "present": false
    },
    {
      "value": 70.0,
      "factor": "weight",
      "points": 0,
      "present": false
    },
    {
      "value": "none",
      "factor": "history_difficult_intubation",
      "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": "el-Ganzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD",
    "doi": "10.1097/00000539-199606000-00017",
    "id": "el-ganzouri-1996",
    "pmid": "8638791",
    "source": "Anesth Analg. 1996;82(6):1197-1204",
    "title": "Preoperative airway assessment: predictive value of a multivariate risk index"
  },
  "formula": "egri",
  "formula_expression": "EGRI = mouth_opening (>4 cm: 0, <=4 cm: 1) + thyromental (>6.5 cm: 0, 6.0-6.5: 1, <6.0: 2) + mallampati (1: 0, 2: 1, 3: 2) + neck_movement (>90 deg: 0, 80-90: 1, <80: 2) + can_prognath (true: 0, false: 1) + weight (<90 kg: 0, 90-110: 1, >110: 2) + history_difficult_intubation (none: 0, questionable: 1, definite: 2); max 12; high_risk if score >= 4",
  "max_score": 12,
  "score": 0,
  "weight_kg": 70.0,
  "high_risk": false,
  "can_prognath": true,
  "egri_band": "lt_4",
  "history_difficult_intubation": "none",
  "mallampati": 1,
  "mouth_opening_cm": 5.0,
  "neck_movement_deg": 100.0,
  "thyromental_cm": 7.0
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_mouth_opening`	mouth_opening_cm must be a number from 0.5 to 10 (El-Ganzouri 1996 interincisor gap). Returned before settlement; you are not charged.
400	`invalid_thyromental`	thyromental_cm must be a number from 2 to 15 (El-Ganzouri 1996 thyromental distance). Returned before settlement; you are not charged.
400	`invalid_egri_mallampati`	mallampati must be 1, 2, or 3 (El-Ganzouri 1996 original Mallampati; Samsoon class 4 is not used). Returned before settlement; you are not charged.
400	`invalid_neck_movement`	neck_movement_deg must be a number from 0 to 180 (El-Ganzouri 1996 head/neck range of motion). Returned before settlement; you are not charged.
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_weight`	weight_kg (1-500) or weight_lb (2-1100) is required Returned before settlement; you are not charged.
400	`invalid_intubation_history`	history_difficult_intubation must be none, questionable, or definite (El-Ganzouri 1996). 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

Mallampati — Return the Samsoon 1987 modified Mallampati class 1-4 from a caller-assigned integer, with a stable label.
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).
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.