Page 20 - JSOM Spring 2021

Performance Characteristics of
Fluid Warming Technology in Austere Environments

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Thomas Blakeman, MS *; John Fowler ;
Richard Branson, MS ; Michael Petro ; Dario Rodriquez Jr, MS 2
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ABSTRACT

Resuscitation of the critically ill or injured is a significant and https://belmontmedtech.com/portable-iv-pump), Thermal Angel
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complex task in any setting, often complicated by environ- (Estill Medical Technologies; https://thermalangel.com/), and
mental influences. Hypothermia is one of the components of M Warmer (MEQU; https://mequ.dk/product/#mwarmer).
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the “Triad of Death” in trauma patients. Devices for warming These devices are shown in Figure 1. The devices were evalu-
IV fluids in the austere environment must be small and porta- ated using two different fluids and flows. Room temperature
ble, able to operate on battery power, warm fluids to normal normal saline (NS) was run at a nonemergent flow of 125mL/h
body temperature (37°C), and perform under various condi- (2.1mL/min) for 1 hour via an Alaris Medsystem III infu-
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tions, including at altitude. The authors evaluated four porta- sion pump (Becton, Dickinson and Company; http://www.bd
ble fluid warmers that are currently fielded or have potential -products.com/products/ivsets/product.php?ID=334) and using
for use in military environments. a pressure bag inflated to 300mmHg to represent an emer-
gent flow, infusing 1L of fluid. These flow rates were cho-
Keywords: intravenous fluids; fluid warming; resuscitation; sen as extremes that may be encountered in far forward and
hypothermia transport military operations based on experience of one of
the authors (JF). During high flows under pressure, flow was
calculated by infusing a measured 1L volume of NS, running
Introduction the fluid through each warmer using the pressure bag, and
measuring the time in seconds to infuse the fluid. Flows for the
Resuscitation of the critically ill or injured is a significant and Buddy Liter, Buddy Lite, M Warmer, and Thermal Angel were
complex task in any setting, often complicated by environ- 278mL/min, 278mL/min, 222mL/min, and 232mL/min, re-
mental influences. Hypothermia is one of the components of spectively. Only one such measurement was made per device.
the “Triad of Death” in trauma patients, frequently seen in
the prehospital setting, and often exacerbated by resuscitation Expired, iced packed red blood cells (PRBCs) were run under
efforts. 1,2–4 Studies have shown that the incidence of hypother- identical conditions as the NS with the exception of using 2
mia in the prehospital setting can reach 43%. Most guide-
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lines classify hypothermia as mild, 35°C to 32°C; moderate, FIGURE 1 The four devices evaluated in the study.
32°C to 28°C; or severe, <28°C. Warming of intravenous
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(IV) fluids is recommended for the mitigation and treatment of
hypothermia in prehospital trauma patients. The US military
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has many of the same needs as civilian prehospital caregivers
but operates under unique conditions. Many casualties require
fluid resuscitation and simultaneous treatment of hypothermia
in the field. Far forward deployed military units do not have
ability to warm large quantities of IV fluids due to weight and
cube constraints. Devices for warming IV fluids in this envi-
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ronment must be small and portable, able to operate on bat-
tery power, warm fluids to normal body temperature (37°C),
and perform under various conditions, including at altitude.
We evaluated four portable fluid warmers that are currently
fielded or have potential for use in military environments.

Methods
The study evaluated four portable fluid warming devices:
Buddy Liter and Buddy Lite AC (Belmont Instrument Corp.;
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*Correspondence to University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267; or thomas.blakeman@uc.edu
Mr Blakeman is an assistant professor and Mr Branson is a professor at the University of Cincinnati College of Medicine, Cincinnati, Ohio. Maj
Fowler is a nurse research coordinator, Col Petro (Ret) is a trauma surgeon, and CMSgt Rodriquez (Ret) is a senior research health science officer
at the US Air Force Research Laboratory, 711th Human Performance Wing, Wright Patterson Air Force Base, OH.
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