# Perioperative DOAC interruption

Perioperative DOAC

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/periop_doac`
HTML: https://magentlab.com/docs/periop-doac
Markdown: https://magentlab.com/docs/periop-doac.md

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

## What it computes

Return published elective perioperative DOAC hold and resume day counts from Douketis 2022 (PAUSE-style implementation considerations, recommendations 22-25) given the INN, procedure bleed-risk category, and dabigatran CrCl when required.

## When to use

When an agent needs the Douketis 2022 elective DOAC interruption table for apixaban, rivaroxaban, edoxaban, or dabigatran and must not apply a warfarin 5-day hold, heparin bridging, or an urgent-surgery pathway.

## When not to use

- Not a medical device. Not a prescription and not an anticoagulation order. A licensed clinician remains responsible for timing around an elective procedure.
- Elective surgery or procedure only. Not urgent or emergency surgery. Not a warfarin or VKA 5-day interruption.
- Recommendation 26 suggests against heparin bridging of a DOAC. heparin_bridge is always false. magent does not order heparin.
- magent does not assay CrCl. The caller assigns CrCl for dabigatran. CrCl must be absent for apixaban, rivaroxaban, and edoxaban.
- INN names only (apixaban, rivaroxaban, edoxaban, dabigatran). Not a diagnosis of bleed risk; the caller assigns low_to_moderate or high.

## Formula

```
Douketis 2022 PAUSE-style elective DOAC interruption (recommendations 22-25): apixaban/rivaroxaban/edoxaban hold 1 day (low_to_moderate) or 2 days (high); dabigatran CrCl>=50 same 1/2; dabigatran CrCl<50 hold 2 (low_to_moderate) or 4 (high); resume 1 day after low_to_moderate or 2 days after high; heparin_bridge always false (recommendation 26)
```

## Citation

[Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline](https://doi.org/10.1016/j.chest.2022.07.025)
Douketis JD, Spyropoulos AC, Murad MH, et al.
Chest. 2022;162(5):e207-e243
DOI: [10.1016/j.chest.2022.07.025](https://doi.org/10.1016/j.chest.2022.07.025)

## Worked example

### Apixaban, low-to-moderate bleed risk

Given: `bleed_risk=low_to_moderate, doac=apixaban`

1. doac is apixaban (factor Xa inhibitor); CrCl is not used
2. bleed_risk is low_to_moderate → hold 1 day before and resume 1 day after
3. heparin_bridge is false (recommendation 26)


### Dabigatran, high bleed risk, CrCl 40

Given: `bleed_risk=high, crcl_ml_min=40, doac=dabigatran`

1. doac is dabigatran and caller-assigned CrCl 40 is < 50
2. bleed_risk is high → hold 4 days before and resume 2 days after
3. heparin_bridge is false (recommendation 26)


## Also searched as

- perioperative DOAC
- DOAC interruption
- PAUSE DOAC
- Douketis perioperative
- elective DOAC hold
- dabigatran CrCl hold
- ACCP antithrombotic
- perioperative apixaban

## Parameters

- `doac` (string, required): Direct oral anticoagulant INN, case-insensitive: apixaban, rivaroxaban, edoxaban, or dabigatran. Elective procedures only. Not warfarin or a VKA.
- `bleed_risk` (string, required): Procedure bleed-risk category from Douketis 2022, case-insensitive: low_to_moderate or high. Caller assigns the category. Not urgent surgery.
- `crcl_ml_min` (number, optional): Caller-assigned creatinine clearance in mL/min (15-120). Required only when doac is dabigatran. Must be absent for apixaban, rivaroxaban, and edoxaban. magent does not assay CrCl.

## 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/periop_doac`
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": [
    {
      "bleed_risk": "low_to_moderate",
      "doac": "apixaban"
    },
    {
      "bleed_risk": "low_to_moderate",
      "doac": "apixaban"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/periop-doac

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/periop_doac",
  "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": "Douketis JD, Spyropoulos AC, Murad MH, et al.",
        "doi": "10.1016/j.chest.2022.07.025",
        "id": "douketis-2022",
        "pmid": "35964704",
        "source": "Chest. 2022;162(5):e207-e243",
        "title": "Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline"
      },
      "formula": "periop_doac",
      "formula_expression": "Douketis 2022 PAUSE-style elective DOAC interruption (recommendations 22-25): apixaban/rivaroxaban/edoxaban hold 1 day (low_to_moderate) or 2 days (high); dabigatran CrCl>=50 same 1/2; dabigatran CrCl<50 hold 2 (low_to_moderate) or 4 (high); resume 1 day after low_to_moderate or 2 days after high; heparin_bridge always false (recommendation 26)",
      "criteria": [
        {
          "value": "apixaban",
          "factor": "doac",
          "met": true
        },
        {
          "value": "low_to_moderate",
          "factor": "high_bleed_risk",
          "met": false
        },
        {
          "factor": "dabigatran",
          "met": false
        },
        {
          "factor": "dabigatran_crcl_lt_50",
          "met": false
        }
      ],
      "bleed_risk": "low_to_moderate",
      "doac": "apixaban",
      "heparin_bridge": false,
      "hold_days_before": 1,
      "resume_days_after": 1,
      "total_pre_post_days": 2
    },
    {
      "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": "Douketis JD, Spyropoulos AC, Murad MH, et al.",
        "doi": "10.1016/j.chest.2022.07.025",
        "id": "douketis-2022",
        "pmid": "35964704",
        "source": "Chest. 2022;162(5):e207-e243",
        "title": "Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline"
      },
      "formula": "periop_doac",
      "formula_expression": "Douketis 2022 PAUSE-style elective DOAC interruption (recommendations 22-25): apixaban/rivaroxaban/edoxaban hold 1 day (low_to_moderate) or 2 days (high); dabigatran CrCl>=50 same 1/2; dabigatran CrCl<50 hold 2 (low_to_moderate) or 4 (high); resume 1 day after low_to_moderate or 2 days after high; heparin_bridge always false (recommendation 26)",
      "criteria": [
        {
          "value": "apixaban",
          "factor": "doac",
          "met": true
        },
        {
          "value": "low_to_moderate",
          "factor": "high_bleed_risk",
          "met": false
        },
        {
          "factor": "dabigatran",
          "met": false
        },
        {
          "factor": "dabigatran_crcl_lt_50",
          "met": false
        }
      ],
      "bleed_risk": "low_to_moderate",
      "doac": "apixaban",
      "heparin_bridge": false,
      "hold_days_before": 1,
      "resume_days_after": 1,
      "total_pre_post_days": 2
    }
  ]
}
```

## Response fields

- `formula` (string): periop_doac
- `formula_expression` (string): Douketis 2022 PAUSE-style elective hold and resume tree
- `doac` (string): Normalized INN: apixaban, rivaroxaban, edoxaban, or dabigatran
- `bleed_risk` (string): Normalized bleed-risk category: low_to_moderate or high
- `crcl_ml_min` (number): Caller-assigned CrCl in mL/min used for dabigatran. Omitted when doac is not dabigatran.
- `hold_days_before` (integer): Days to hold the DOAC before an elective procedure
- `resume_days_after` (integer): Days after the procedure before resuming the DOAC
- `heparin_bridge` (boolean): Always false. Recommendation 26 suggests against heparin bridging of a DOAC.
- `total_pre_post_days` (integer): hold_days_before plus resume_days_after
- `criteria` (array): Tree rows for doac, high_bleed_risk, dabigatran, and dabigatran_crcl_lt_50
- `citation` (object): Douketis 2022 Chest 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": "Douketis JD, Spyropoulos AC, Murad MH, et al.",
    "doi": "10.1016/j.chest.2022.07.025",
    "id": "douketis-2022",
    "pmid": "35964704",
    "source": "Chest. 2022;162(5):e207-e243",
    "title": "Perioperative Management of Antithrombotic Therapy: An American College of Chest Physicians Clinical Practice Guideline"
  },
  "formula": "periop_doac",
  "formula_expression": "Douketis 2022 PAUSE-style elective DOAC interruption (recommendations 22-25): apixaban/rivaroxaban/edoxaban hold 1 day (low_to_moderate) or 2 days (high); dabigatran CrCl>=50 same 1/2; dabigatran CrCl<50 hold 2 (low_to_moderate) or 4 (high); resume 1 day after low_to_moderate or 2 days after high; heparin_bridge always false (recommendation 26)",
  "criteria": [
    {
      "value": "apixaban",
      "factor": "doac",
      "met": true
    },
    {
      "value": "low_to_moderate",
      "factor": "high_bleed_risk",
      "met": false
    },
    {
      "factor": "dabigatran",
      "met": false
    },
    {
      "factor": "dabigatran_crcl_lt_50",
      "met": false
    }
  ],
  "bleed_risk": "low_to_moderate",
  "doac": "apixaban",
  "heparin_bridge": false,
  "hold_days_before": 1,
  "resume_days_after": 1,
  "total_pre_post_days": 2
}
```

## Errors

- HTTP 400 `invalid_periop_doac`: Perioperative DOAC hold inputs must match Douketis 2022 drug, bleed-risk category, and dabigatran CrCl window from that guideline. 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

- [DOAC Score](https://magentlab.com/docs/doac-score) — Compute the Aggarwal 2023 DOAC Score from age, CrCl or eGFR, and caller-assigned Table 2 flags for patients with atrial fibrillation on a DOAC.
- [HAS-BLED](https://magentlab.com/docs/has-bled) — Compute the HAS-BLED bleeding-risk score from discrete clinical flags.

## 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.