Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A rapid infuser is a device that delivers warmed fluid at very high flow rates. It combines a high-speed pump, a fluid warmer and air-removal safeguards in one system. Clinic staff, buyers and students use this page to tell a rapid infuser apart from a simple fluid warmer or an ordinary infusion pump.
What is a rapid infuser?
A rapid infuser is a pump-plus-warmer system built for situations where large volumes must be given quickly and the fluid must not chill the patient. Belmont Medical Technologies, whose Belmont Rapid Infuser RI-2 is used here as a worked example, describes its device as a high-speed peristaltic pump that heats fluid as it flows, and lists hypothermia and blood loss as the problems it is meant to combat (belmontmedtech.com, checked 2026-10-30). The figures below describe that one product, not every rapid infuser.
Who uses it: the manufacturer lists trauma and emergency care, anesthesia, surgical care, labor and delivery, intensive care and military use.
How a rapid infuser is built
The example device has three working parts, all described on the manufacturer’s product page:
- Pump. A peristaltic pump with flow rates from 2.5 to 1,000 ml/min.
- Heater. Dry electromagnetic induction heats stainless-steel rings placed in the fluid path, so the fluid is warmed inline rather than in a water bath. The manufacturer reports reaching 35 C in about 19 seconds and 37.5 C in about 41 seconds; the page prints an average input fluid temperature of 2.3 C beside them but gives no flow rate or other test details, so treat these as manufacturer-reported figures.
- Reservoir and set. A 3.0 L Large Volume Reservoir (LVR), supplied six to a box, with a heat exchanger set. The manufacturer says the system fully primes in under one minute and can be re-primed without disconnecting from the patient.
Rapid infuser vs fluid warmer vs infusion pump
These three terms are often mixed up. The table separates them using the FDA’s pump definition and the wording of the federal blood-warmer regulation, 21 CFR 864.9205 (eCFR, checked 2026-10-30).
| Device | What it does | Source |
|---|---|---|
| External infusion pump | Delivers fluids into a patient’s body in a controlled manner. It is not defined as a warmer. | FDA, What is an infusion pump |
| Nonelectromagnetic blood or plasma warming device | Warms blood or plasma by means other than electromagnetic radiation before it is given to a patient. Regulated as Class II (performance standards). | 21 CFR 864.9205(a) |
| Electromagnetic blood and plasma warming device | Uses electromagnetic radiation (radiowaves or microwaves) to warm a bag or bottle of blood or plasma. Regulated as Class III (premarket approval). | 21 CFR 864.9205(b) |
| Rapid infuser (Belmont RI-2 example) | A high-speed pump and an inline heater in one system, with air detection. The manufacturer’s page describes its pump and heating method. | belmontmedtech.com |
The regulation text does not name any specific rapid infuser, so this page does not assign a particular product to either class. Check a product’s labeling and FDA listing for its classification.
Safety features to know about
High flow rates make air detection and pressure control central to the design. The example manufacturer lists these features:
- Two ultrasonic air detectors and a patient safety valve to guard against air emboli, plus automatic air removal.
- Automatic pressure monitoring, with flow rate adjusted when pressure exceeds 300 mmHg.
The instructions for use (IFU) for a specific model are the authority on warnings, contraindications, set-up and alarms; the product page does not replace them.
Common mistakes
- Treating a fluid warmer as a rapid infuser. A warmer by itself, as described in 21 CFR 864.9205, warms blood or plasma; the regulation does not describe a pump.
- Quoting one brand’s flow rate or warming time as the figure for every rapid infuser.
- Reading manufacturer warm-up times as if they applied at any flow rate or fluid temperature, when the source gives only an input fluid temperature.
FAQ
What is a rapid infuser?
A rapid infuser is a high-flow pump that also warms the fluid it delivers and removes air from the line. In the Belmont RI-2 example, flow rates run from 2.5 to 1,000 ml/min with inline induction heating.
Is a rapid infuser the same as an infusion pump?
No. An external infusion pump delivers fluids in a controlled manner (FDA). A rapid infuser is described by its manufacturer as adding high-speed delivery, warming and air removal to that function.
Related reading
For general infusion hardware, see infusion supplies and pump selection, what blood tubing is, what an IV catheter is, and the transfusion service supply checklist. Catalogue category: infusion pumps.
Sources
- Belmont Medical Technologies, Rapid Infusion Pump (Belmont Rapid Infuser RI-2): https://www.belmontmedtech.com/rapid-infusion-pump, checked 2026-10-30.
- eCFR, 21 CFR 864.9205, Blood and plasma warming device: https://www.ecfr.gov/current/title-21/section-864.9205, checked 2026-10-30.
- U.S. FDA, What is an infusion pump: https://www.fda.gov/medical-devices/infusion-pumps/what-infusion-pump, checked 2026-10-30.
