# El-Ganzouri risk index (EGRI) EGRI Status: LIVE Price: $0.005 USDC `GET /api/calc/egri` HTML: https://magentlab.com/docs/egri Markdown: https://magentlab.com/docs/egri.md 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 [Preoperative airway assessment: predictive value of a multivariate risk index](https://doi.org/10.1097/00000539-199606000-00017) el-Ganzouri AR, McCarthy RJ, Tuman KJ, Tanck EN, Ivankovich AD Anesth Analg. 1996;82(6):1197-1204 DOI: [10.1097/00000539-199606000-00017](https://doi.org/10.1097/00000539-199606000-00017) ## Worked example ### All low-risk items Given: `can_prognath=true, history_difficult_intubation=none, mallampati=1, mouth_opening_cm=5, neck_movement_deg=100, thyromental_cm=7, weight_kg=70` 1. mouth_opening 5 >4 → 0; thyromental 7 >6.5 → 0; mallampati 1 → 0 2. neck 100 >90 → 0; can_prognath true → 0; weight 70 <90 → 0; history none → 0 3. score = 0 (max 12); high_risk false; egri_band lt_4 ### Mallampati 3 and definite difficult-intubation history Given: `can_prognath=true, history_difficult_intubation=definite, mallampati=3, mouth_opening_cm=5, neck_movement_deg=100, thyromental_cm=7, weight_kg=70` 1. mallampati 3 → 2; history definite → 2; all other items 0 2. 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 ## Parameters - `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): 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. Method: `POST /api/calc/egri` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: 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: ```json { "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" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/egri Example 200: ```json { "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 fields - `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 Frozen fixture. Not a live lookup. ```json { "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 } ``` ## Errors - HTTP 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. - HTTP 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. - HTTP 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. - HTTP 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. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_weight`: weight_kg (1-500) or weight_lb (2-1100) is required Returned before settlement; you are not charged. - HTTP 400 `invalid_intubation_history`: history_difficult_intubation must be none, questionable, or definite (El-Ganzouri 1996). Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [Mallampati](https://magentlab.com/docs/mallampati) — Return the Samsoon 1987 modified Mallampati class 1-4 from a caller-assigned integer, with a stable label. - [HEAVEN](https://magentlab.com/docs/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](https://magentlab.com/docs/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. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional. - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/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.