Hematology · LIVE
Allowable blood loss
Compute Gross 1983 dilution-corrected allowable blood loss from a caller-supplied estimated blood volume and initial versus target hematocrit.
Markdown: /docs/allowable-blood-loss.md · Canonical: https://magentlab.com/docs/allowable-blood-loss
Not a medical device. Not a diagnosis, dose, or listing recommendation.
What it computes
Compute Gross 1983 dilution-corrected allowable blood loss from a caller-supplied estimated blood volume and initial versus target hematocrit.
When to use
When an agent needs published Gross ABL and must not invent milliliters, compute Nadler EBV inside this tool, or use the uncorrected EBV*(Hi-Hf)/Hi form.
When not to use
- Not a transfusion trigger or order. magent does not choose a product, rate, or threshold.
- Estimated blood volume is caller-supplied. This tool does not compute Nadler EBV from height, weight, or sex.
- Dilution-corrected Gross 1983 only. Not the uncorrected EBV * (Hi - Hf) / Hi form.
Formula
abl_ml = estimated_blood_volume_ml * (hct_initial_percent - hct_target_percent) / ((hct_initial_percent + hct_target_percent) / 2)
Citation
- Authors
- Gross JB
- Source
- Anesthesiology. 1983;58(3):277-280
Worked example
EBV 5000 mL, Hct 40 to 30
Given:
estimated_blood_volume_ml=5000hct_initial_percent=40hct_target_percent=30
- Hct_avg = (40 + 30) / 2 = 35
- abl_ml = 5000 * (40 - 30) / 35 = 1428.6 mL
Also searched as
- allowable blood loss
- maximum allowable blood loss
- Gross ABL
- ABL formula
- dilution-corrected ABL
- allowable blood loss hematocrit
- MABL
Try
Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.
Full URL: https://api.magentlab.com/api/calc/allowable_blood_loss?estimated_blood_volume_ml=5000&hct_initial_percent=40&hct_target_percent=30
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/allowable_blood_loss?estimated_blood_volume_ml=5000&hct_initial_percent=40&hct_target_percent=30"
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
estimated_blood_volume_ml |
number | required | Caller-supplied estimated blood volume in mL (50-15000). Required. magent does not compute Nadler EBV. |
hct_initial_percent |
number | required | Initial hematocrit as a percent (10-70). |
hct_target_percent |
number | required | Target hematocrit as a percent (10-70). Must be strictly less than hct_initial_percent. |
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.
- 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": [
{
"estimated_blood_volume_ml": "5000",
"hct_initial_percent": "40",
"hct_target_percent": "30"
},
{
"estimated_blood_volume_ml": "5000",
"hct_initial_percent": "40",
"hct_target_percent": "30"
}
]
}
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/allowable_blood_loss",
"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": "Gross JB",
"doi": "10.1097/00000542-198303000-00016",
"id": "gross-1983",
"source": "Anesthesiology. 1983;58(3):277-280",
"title": "Estimating allowable blood loss: corrected for dilution"
},
"formula": "gross_1983",
"formula_expression": "abl_ml = estimated_blood_volume_ml * (hct_initial_percent - hct_target_percent) / ((hct_initial_percent + hct_target_percent) / 2)",
"abl_ml": 1428.6,
"estimated_blood_volume_ml": 5.0e3,
"hct_initial_percent": 40.0,
"hct_target_percent": 30.0
},
{
"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": "Gross JB",
"doi": "10.1097/00000542-198303000-00016",
"id": "gross-1983",
"source": "Anesthesiology. 1983;58(3):277-280",
"title": "Estimating allowable blood loss: corrected for dilution"
},
"formula": "gross_1983",
"formula_expression": "abl_ml = estimated_blood_volume_ml * (hct_initial_percent - hct_target_percent) / ((hct_initial_percent + hct_target_percent) / 2)",
"abl_ml": 1428.6,
"estimated_blood_volume_ml": 5.0e3,
"hct_initial_percent": 40.0,
"hct_target_percent": 30.0
}
]
}
Response
| Field | Type | Description |
|---|---|---|
formula |
string | gross_1983 |
formula_expression |
string | Exact Gross 1983 expression |
estimated_blood_volume_ml |
number | Caller-supplied estimated blood volume in mL |
hct_initial_percent |
number | Initial hematocrit percent used |
hct_target_percent |
number | Target hematocrit percent used |
abl_ml |
number | Dilution-corrected allowable blood loss in mL, 1 decimal |
citation |
object | Gross Anesthesiology 1983 citation |
disclaimer |
string | Not-a-device notice |
Example JSON
Machine form of the same example. Frozen fixture. Not a live lookup.
{
"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": "Gross JB",
"doi": "10.1097/00000542-198303000-00016",
"id": "gross-1983",
"source": "Anesthesiology. 1983;58(3):277-280",
"title": "Estimating allowable blood loss: corrected for dilution"
},
"formula": "gross_1983",
"formula_expression": "abl_ml = estimated_blood_volume_ml * (hct_initial_percent - hct_target_percent) / ((hct_initial_percent + hct_target_percent) / 2)",
"abl_ml": 1428.6,
"estimated_blood_volume_ml": 5.0e3,
"hct_initial_percent": 40.0,
"hct_target_percent": 30.0
}
Client errors (HTTP 400)
Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.
| HTTP | Code | When |
|---|---|---|
| 400 | invalid_estimated_blood_volume |
estimated_blood_volume_ml must be a number from 50 to 15000. Returned before settlement; you are not charged. |
| 400 | invalid_hematocrit |
hematocrit_percent must be a number from 10 to 70. Returned before settlement; you are not charged. |
| 400 | invalid_target_hematocrit |
hct_target_percent must be 10-70 and strictly less than hct_initial_percent. 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
- Nadler blood volume — Compute Nadler 1962 predicted blood volume in liters and milliliters from height, weight, and sex.
- ANC — Compute absolute neutrophil count from WBC and neutrophil plus band percents, plus a Bodey 1966 granulocyte 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.
- 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.