# King's College criteria King's College criteria Status: LIVE Price: $0.005 USDC `GET /api/calc/kings_college` HTML: https://magentlab.com/docs/kings-college Markdown: https://magentlab.com/docs/kings-college.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply the O'Grady 1989 King's College poor-prognosis criteria for fulminant hepatic failure, with separate acetaminophen and non-acetaminophen trees using prothrombin time in seconds. ## When to use When an agent has caller-assigned labs and encephalopathy grade in fulminant hepatic failure and needs the 1989 King's College criteria, not later INR restatements or a transplant-allocation score. ## When not to use - Not a medical device. magent does not examine the patient. - Not a transplant listing, organ-allocation order, or UNOS/MELD substitute. - Uses prothrombin time in seconds as published in 1989. Does not accept, convert, or restate INR (no INR>6.5 / INR>3.5). - This is the O'Grady 1989 Gastroenterology paper only. Later reviews and age <10 restatements are not this tool. Age cutoffs are <11 or >40 as in the 1989 abstract. - The acetaminophen arterial pH <7.30 rule is independent of encephalopathy. The PT>100 s plus creatinine >300 umol/L plus grade III/IV package is the 1989 selection model. ## Formula ``` acetaminophen: arterial_ph < 7.30, or (pt_sec > 100 and creatinine_umol_l > 300 and encephalopathy_grade >= 3); non_acetaminophen: pt_sec > 100, or at least 3 of (age_years < 11 or > 40; unfavorable_etiology; jaundice_to_encephalopathy_days > 7; bilirubin_umol_l > 300; pt_sec > 50) ``` ## Citation [Early indicators of prognosis in fulminant hepatic failure](https://doi.org/10.1016/0016-5085(89)90081-4) O'Grady JG, Alexander GJ, Hayllar KM, Williams R Gastroenterology. 1989;97(2):439-445 DOI: [10.1016/0016-5085(89)90081-4](https://doi.org/10.1016/0016-5085(89)90081-4) ## Worked example ### Acetaminophen, labs not meeting either rule Given: `age_years=30, arterial_ph=7.40, bilirubin_umol_l=50, creatinine_umol_l=80, encephalopathy_grade=1, etiology=acetaminophen, jaundice_to_encephalopathy_days=2, pt_sec=20, unfavorable_etiology=false` 1. Acetaminophen tree: arterial pH 7.40 is not < 7.30 2. PT 20 s is not > 100, creatinine 80 umol/L is not > 300, grade 1 is not >= 3 3. criteria_met is false ### Acetaminophen arterial pH < 7.30 Given: `age_years=30, arterial_ph=7.20, bilirubin_umol_l=50, creatinine_umol_l=80, encephalopathy_grade=1, etiology=acetaminophen, jaundice_to_encephalopathy_days=2, pt_sec=20, unfavorable_etiology=false` 1. Acetaminophen tree: arterial pH 7.20 < 7.30 2. pH rule is independent of encephalopathy 3. criteria_met is true ### Non-acetaminophen any three of five Given: `age_years=10, arterial_ph=7.40, bilirubin_umol_l=50, creatinine_umol_l=80, encephalopathy_grade=1, etiology=non_acetaminophen, jaundice_to_encephalopathy_days=8, pt_sec=20, unfavorable_etiology=true` 1. Non-acetaminophen tree: PT 20 s is not > 100 2. Age 10 < 11, unfavorable etiology, jaundice-to-encephalopathy 8 > 7 (three of five) 3. criteria_met is true ## Also searched as - kings college - acetaminophen - fulminant hepatic failure - King's College criteria - O'Grady 1989 - paracetamol hepatotoxicity criteria - King's College Hospital criteria - non-acetaminophen FHF ## Parameters - `etiology` (string, required): acetaminophen or non_acetaminophen (O'Grady 1989). Selects the paracetamol or non-paracetamol poor-prognosis tree. Required on every request. - `arterial_ph` (number, required): Arterial pH (6.80-7.80). Acetaminophen criterion met when pH < 7.30, independent of encephalopathy. Required even on the non-acetaminophen tree; not scored there. - `pt_sec` (number, required): Prothrombin time in seconds (8-120) as published in 1989. INR is not accepted. Acetaminophen combo uses PT > 100; non-acetaminophen uses PT > 100 alone or PT > 50 as one of five factors. - `creatinine_umol_l` (number, required): Serum creatinine in umol/L (9-1768). Acetaminophen combo criterion met when > 300. Required even on the non-acetaminophen tree; not scored there. - `encephalopathy_grade` (integer, required): Hepatic encephalopathy grade 0-4 as assigned by the caller (Conn 1977 / West Haven). Acetaminophen combo uses grade >= 3 (grade III/IV). Required even on the non-acetaminophen tree; not scored there. magent does not examine the patient. - `age_years` (integer, required): Age in years (0-120). Non-acetaminophen factor met when age < 11 or age > 40 (1989 abstract, not a later <10 restatement). Required even on the acetaminophen tree; not scored there. - `unfavorable_etiology` (boolean, required): Unfavorable etiology as assigned by the caller (paper: non-A non-B hepatitis or drug reaction). true or false. Non-acetaminophen any-3 factor. Required even on the acetaminophen tree; not scored there. - `jaundice_to_encephalopathy_days` (integer, required): Days from jaundice to encephalopathy (integer 0-90). Non-acetaminophen factor met when > 7. Required even on the acetaminophen tree; not scored there. - `bilirubin_umol_l` (number, required): Serum bilirubin in umol/L (2-684). Non-acetaminophen factor met when > 300. Required even on the acetaminophen tree; not scored there. ## 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/kings_college` 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": [ { "age_years": "30", "arterial_ph": "7.40", "bilirubin_umol_l": "50", "creatinine_umol_l": "80", "encephalopathy_grade": "1", "etiology": "acetaminophen", "jaundice_to_encephalopathy_days": "2", "pt_sec": "20", "unfavorable_etiology": "false" }, { "age_years": "30", "arterial_ph": "7.40", "bilirubin_umol_l": "50", "creatinine_umol_l": "80", "encephalopathy_grade": "1", "etiology": "acetaminophen", "jaundice_to_encephalopathy_days": "2", "pt_sec": "20", "unfavorable_etiology": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/kings-college Example 200: ```json { "count": 2, "path": "/api/calc/kings_college", "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": "O'Grady JG, Alexander GJ, Hayllar KM, Williams R", "doi": "10.1016/0016-5085(89)90081-4", "id": "ogrady-1989", "pmid": "2490426", "source": "Gastroenterology. 1989;97(2):439-445", "title": "Early indicators of prognosis in fulminant hepatic failure" }, "formula": "kings_college", "formula_expression": "acetaminophen: arterial_ph < 7.30, or (pt_sec > 100 and creatinine_umol_l > 300 and encephalopathy_grade >= 3); non_acetaminophen: pt_sec > 100, or at least 3 of (age_years < 11 or > 40; unfavorable_etiology; jaundice_to_encephalopathy_days > 7; bilirubin_umol_l > 300; pt_sec > 50)", "criteria": [ { "value": 7.4, "factor": "arterial_ph_lt_7_30", "met": false }, { "value": 20.0, "factor": "pt_sec_gt_100", "met": false }, { "value": 80.0, "factor": "creatinine_umol_l_gt_300", "met": false }, { "value": 1, "factor": "encephalopathy_grade_ge_3", "met": false } ], "criteria_met": false, "etiology": "acetaminophen" }, { "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": "O'Grady JG, Alexander GJ, Hayllar KM, Williams R", "doi": "10.1016/0016-5085(89)90081-4", "id": "ogrady-1989", "pmid": "2490426", "source": "Gastroenterology. 1989;97(2):439-445", "title": "Early indicators of prognosis in fulminant hepatic failure" }, "formula": "kings_college", "formula_expression": "acetaminophen: arterial_ph < 7.30, or (pt_sec > 100 and creatinine_umol_l > 300 and encephalopathy_grade >= 3); non_acetaminophen: pt_sec > 100, or at least 3 of (age_years < 11 or > 40; unfavorable_etiology; jaundice_to_encephalopathy_days > 7; bilirubin_umol_l > 300; pt_sec > 50)", "criteria": [ { "value": 7.4, "factor": "arterial_ph_lt_7_30", "met": false }, { "value": 20.0, "factor": "pt_sec_gt_100", "met": false }, { "value": 80.0, "factor": "creatinine_umol_l_gt_300", "met": false }, { "value": 1, "factor": "encephalopathy_grade_ge_3", "met": false } ], "criteria_met": false, "etiology": "acetaminophen" } ] } ``` ## Response fields - `formula` (string): kings_college - `formula_expression` (string): O'Grady 1989 acetaminophen and non-acetaminophen poor-prognosis trees - `criteria_met` (boolean): true when the selected 1989 tree indicates poor prognosis. Not a transplant listing or organ-allocation order. - `etiology` (string): acetaminophen or non_acetaminophen tree used - `criteria` (array): Selected-tree factors only, each with factor, met, and value when numeric - `citation` (object): O'Grady 1989 Gastroenterology citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "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": "O'Grady JG, Alexander GJ, Hayllar KM, Williams R", "doi": "10.1016/0016-5085(89)90081-4", "id": "ogrady-1989", "pmid": "2490426", "source": "Gastroenterology. 1989;97(2):439-445", "title": "Early indicators of prognosis in fulminant hepatic failure" }, "formula": "kings_college", "formula_expression": "acetaminophen: arterial_ph < 7.30, or (pt_sec > 100 and creatinine_umol_l > 300 and encephalopathy_grade >= 3); non_acetaminophen: pt_sec > 100, or at least 3 of (age_years < 11 or > 40; unfavorable_etiology; jaundice_to_encephalopathy_days > 7; bilirubin_umol_l > 300; pt_sec > 50)", "criteria": [ { "value": 7.4, "factor": "arterial_ph_lt_7_30", "met": false }, { "value": 20.0, "factor": "pt_sec_gt_100", "met": false }, { "value": 80.0, "factor": "creatinine_umol_l_gt_300", "met": false }, { "value": 1, "factor": "encephalopathy_grade_ge_3", "met": false } ], "criteria_met": false, "etiology": "acetaminophen" } ``` ## Errors - HTTP 400 `invalid_kings_etiology`: etiology must be acetaminophen or non_acetaminophen (O'Grady 1989). Returned before settlement; you are not charged. - HTTP 400 `invalid_arterial_ph`: arterial_ph must be a number from 6.80 to 7.80. Returned before settlement; you are not charged. - HTTP 400 `invalid_prothrombin_time`: pt_sec (8-120) is required, or pt_patient_sec (8-120) and pt_control_sec (8-20) are required. Returned before settlement; you are not charged. - HTTP 400 `invalid_creatinine`: creatinine_mg_dl (0.1-20) or creatinine_umol_l (9-1768) is required Returned before settlement; you are not charged. - HTTP 400 `invalid_west_haven_grade`: grade must be an integer from 0 to 4 (Conn 1977). Returned before settlement; you are not charged. - HTTP 400 `invalid_kings_age`: age_years must be a number from 0 to 120 (O'Grady 1989 includes children). 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_jaundice_days`: jaundice_to_encephalopathy_days must be an integer from 0 to 90. Returned before settlement; you are not charged. - HTTP 400 `invalid_bilirubin`: bilirubin_mg_dl (0.1-40) or bilirubin_umol_l (2-684) is required 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 - [Lille score](https://magentlab.com/docs/lille) — Compute the Louvet 2007 Lille score from age, day-0 albumin, bilirubin on day 0 and day 7, creatinine, and PT seconds or INR. formula is required. - [Maddrey DF](https://magentlab.com/docs/maddrey) — Compute the 1978 Maddrey discriminant function from patient PT, control PT, and bilirubin. - [MELD-Na](https://magentlab.com/docs/meld-na) — Compute OPTN/UNOS 2016 MELD and MELD-Na from creatinine, bilirubin, INR, sodium, and dialysis. - [West Haven](https://magentlab.com/docs/west-haven) — Return the Conn 1977 (West Haven / Conn score) hepatic encephalopathy grade 0-4 from a caller-assigned integer. ## 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 echoing accepted, payload, and extensions when present). - 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. - 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.