# IV gravity drip rate (INS)

IV gravity drip rate (INS)

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/iv_drip`
HTML: https://magentlab.com/docs/iv-drip
Markdown: https://magentlab.com/docs/iv-drip.md

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

## What it computes

Compute a gravity infusion rate in drops per minute from volume, duration, and the administration-set drop factor (10, 15, or 20 gtt/mL macrodrip or 60 gtt/mL microdrip), and the equivalent mL/hour.

## When to use

When an agent needs the INS gravity gtt/min identity from a caller-assigned volume, time, and printed drop factor and must not invent a pump mL/hour order or a drug dose.

## When not to use

- Not a medical device. Not a pump program, drug order, or infusion prescription. magent does not set an infusion pump.
- Gravity drip only. Drop factor is the caller-assigned administration-set calibration printed on the tubing (10, 15, or 20 gtt/mL macrodrip; 60 gtt/mL microdrip). magent does not choose tubing.
- gtt/min is rounded half away from zero to an integer because the cited standard does not specify a rounding mode. ml_per_hour is volume_ml / (time_min/60).
- Not Webb 2016 pneumonia DRIP (that is a different magent tool).

## Formula

```
gtt_per_min = round_half_away((volume_ml * drop_factor_gtt_ml) / time_min); ml_per_hour = volume_ml / (time_min / 60)
```

## Citation

[Infusion Therapy Standards of Practice, 8th Edition](https://doi.org/10.1097/NAN.0000000000000396)
Gorski LA, Hadaway L, Hagle ME, Broadhurst D, Clare S, Kleidon T, Meyer BM, Nickel B, Rowley S, Sharpe E, Alexander M
J Infus Nurs. 2021;44(1S Suppl 1):S1-S224
DOI: [10.1097/NAN.0000000000000396](https://doi.org/10.1097/NAN.0000000000000396)

## Worked example

### 1000 mL over 480 min, drop factor 15

Given: `drop_factor_gtt_ml=15, time_min=480, volume_ml=1000`

1. gtt_per_min = (1000 × 15) / 480 = 31.25 → 31 (half away from zero to integer)
2. ml_per_hour = 1000 / (480 / 60) = 125


### 1000 mL over 480 min, microdrip 60

Given: `drop_factor_gtt_ml=60, time_min=480, volume_ml=1000`

1. gtt_per_min = (1000 × 60) / 480 = 125
2. ml_per_hour = 125; with 60 gtt/mL, integer gtt/min equals mL/hour


### 1000 mL over 60 min, drop factor 15

Given: `drop_factor_gtt_ml=15, time_min=60, volume_ml=1000`

1. gtt_per_min = (1000 × 15) / 60 = 250
2. ml_per_hour = 1000 / (60 / 60) = 1000


## Also searched as

- IV drip rate
- gtt/min
- gravity infusion
- macrodrip
- microdrip
- drop factor
- INS infusion standards
- drops per minute

## Parameters

- `volume_ml` (number, required): Infused volume in mL (1-10000, magent clamp). Caller-assigned bag or syringe volume; magent does not choose a fluid.
- `time_min` (integer, required): Infusion duration in minutes (1-1440, magent clamp). Convert hours to minutes before calling (8 hours = 480).
- `drop_factor_gtt_ml` (integer, required): Administration-set drop factor in gtt/mL printed on the tubing package: 10, 15, or 20 (macrodrip) or 60 (microdrip). Integers 10, 15, 20, or 60 only. magent does not choose tubing.

## 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/iv_drip`
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": [
    {
      "drop_factor_gtt_ml": "15",
      "time_min": "480",
      "volume_ml": "1000"
    },
    {
      "drop_factor_gtt_ml": "15",
      "time_min": "480",
      "volume_ml": "1000"
    }
  ]
}
```

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

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/iv_drip",
  "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": "Gorski LA, Hadaway L, Hagle ME, Broadhurst D, Clare S, Kleidon T, Meyer BM, Nickel B, Rowley S, Sharpe E, Alexander M",
        "doi": "10.1097/NAN.0000000000000396",
        "id": "gorski-ins-infusion-standards",
        "pmid": "33394637",
        "source": "J Infus Nurs. 2021;44(1S Suppl 1):S1-S224",
        "title": "Infusion Therapy Standards of Practice, 8th Edition"
      },
      "formula": "iv_drip",
      "formula_expression": "gtt_per_min = round_half_away((volume_ml * drop_factor_gtt_ml) / time_min); ml_per_hour = volume_ml / (time_min / 60)",
      "volume_ml": 1000,
      "drop_factor_gtt_ml": 15,
      "gtt_per_min": 31,
      "ml_per_hour": 125,
      "time_min": 480
    },
    {
      "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": "Gorski LA, Hadaway L, Hagle ME, Broadhurst D, Clare S, Kleidon T, Meyer BM, Nickel B, Rowley S, Sharpe E, Alexander M",
        "doi": "10.1097/NAN.0000000000000396",
        "id": "gorski-ins-infusion-standards",
        "pmid": "33394637",
        "source": "J Infus Nurs. 2021;44(1S Suppl 1):S1-S224",
        "title": "Infusion Therapy Standards of Practice, 8th Edition"
      },
      "formula": "iv_drip",
      "formula_expression": "gtt_per_min = round_half_away((volume_ml * drop_factor_gtt_ml) / time_min); ml_per_hour = volume_ml / (time_min / 60)",
      "volume_ml": 1000,
      "drop_factor_gtt_ml": 15,
      "gtt_per_min": 31,
      "ml_per_hour": 125,
      "time_min": 480
    }
  ]
}
```

## Response fields

- `formula` (string): iv_drip
- `formula_expression` (string): Exact expression used
- `volume_ml` (number): Volume in mL used in the rate
- `time_min` (integer): Duration in minutes used in the rate
- `drop_factor_gtt_ml` (integer): Caller-assigned 10, 15, 20, or 60 gtt/mL
- `gtt_per_min` (integer): Gravity drip rate in drops per minute, rounded half away from zero to an integer
- `ml_per_hour` (number): volume_ml / (time_min / 60), 1 decimal then integer when whole
- `citation` (object): INS Infusion Therapy Standards 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": "Gorski LA, Hadaway L, Hagle ME, Broadhurst D, Clare S, Kleidon T, Meyer BM, Nickel B, Rowley S, Sharpe E, Alexander M",
    "doi": "10.1097/NAN.0000000000000396",
    "id": "gorski-ins-infusion-standards",
    "pmid": "33394637",
    "source": "J Infus Nurs. 2021;44(1S Suppl 1):S1-S224",
    "title": "Infusion Therapy Standards of Practice, 8th Edition"
  },
  "formula": "iv_drip",
  "formula_expression": "gtt_per_min = round_half_away((volume_ml * drop_factor_gtt_ml) / time_min); ml_per_hour = volume_ml / (time_min / 60)",
  "volume_ml": 1000,
  "drop_factor_gtt_ml": 15,
  "gtt_per_min": 31,
  "ml_per_hour": 125,
  "time_min": 480
}
```

## Errors

- HTTP 400 `invalid_iv_drip`: IV drip-rate inputs must match volume, time, and drop factor as published for gtt/min. 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

- [NICE adult IV maintenance](https://magentlab.com/docs/nice-iv-maintenance) — Compute NICE CG174 adult hospital routine maintenance water (20, 25, or 30 mL/kg/day), approximately 1 mmol/kg/day sodium, potassium, and chloride each, and the fixed 50–100 g/day glucose range.
- [Parkland formula](https://magentlab.com/docs/parkland) — Compute adult Parkland 24-hour crystalloid volume from weight and percent TBSA, with half allotted to the first 8 hours from the time of burn.

## 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.