Page 13 - JSOM Winter 2022

200mL/min, but no recommendations for red cells. No
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WB/PRBC or colloid experimental trials currently exist
with the enFlow at this time.
• Saline. At 5°C input saline temperatures, the enFlow heated
saline to a combined average output temperature of 39.5°C
6
for all flow rate groups (25–100mL/min). At 10°C input
saline temperatures, the enFlow warmed saline to >38°C
6–8
FIGURE 4 Thermal for flow rates up to 100mL/min. In terms of effective sa-
Angel with UB1 line volume warmed, for 20°C input saline temperatures
Battery Pack. at 100mL/min, the enFlow heated 2.8L to >36°C before
its battery depleted. For 10°C input saline temperatures at
8
100mL/min, the enFlow produced an average output tem-
perature of 33.7°C for 1.8L. 8
• Time to Peak Heating, Maximum Flow Rates, and Battery
Characteristics. The enFlow reaches time to peak heating in
13.4 and 18.3 seconds with 20°C and 5°C input saline at
fixed flow rates (30, 50, and 100mL/min). Maximum flow
6
rates through a 14-gauge PIV pressurized system yields
8
personnel (combat medics, flight medics, and FSEs) most com- 414mL/min and 488mL/min. The enFlow is capable of ei-
monly carry BRAUN 18-gauge IV catheters. Per JTS guide- ther adapting AC power or using a portable battery system
lines for DCR management, IV fluid warmers should ideally (66 wh).
warm blood products to 37°C without substantially reducing • Aluminum Elution. The enFlow’s unprotected heat plate
flow rates. Last, a massive blood transfusion constitutes ≥10 elutes aluminum at different concentrations depending on
units of red blood cells (RBCs) and/or whole blood (WB) in the following variables: type of crystalloid, type of blood
24 hours. 1 product, and flow rate. The FDA recommends the maxi-
mum level of aluminum in IV nutrition to not exceed
3,4
Experimental designs included in this review tested the perfor- 25µg/L. Renal function status influences the rate of elim-
mance capabilities for the Buddy Lite, enFlow, and Thermal ination, but this varies with patients depending on their
3
Angel. The outcomes of interest include average fluid outlet age. In infants, repeated large aluminum exposures may
temperatures, volume of fluid effectively warmed, time to peak lead to neurological impairment and bone growth malfor-
3
heating, maximum flow rates, and battery characteristics with mation. See Table 1 for aluminum elution concentrations
each device. The authors further explore each device’s perfor- at 60-minute durations for varied crystalloids and blood
mance capabilities with crystalloid/colloid, and WB/PRBCs. products. 4
Buddy Lite. Manufacturer recommendations state the heating TABLE 1 Mean Aluminum Concentrations From Crystalloid and
element can warm IV fluids to physiologic temperatures for Blood Products Warmed via enFlow (40°C) at 2 and 16mL/min 4
ambient cooled crystalloids up to 80mL/min, and for 10°C red Aluminum (mg/L)
cells up to 50mL/min. No colloid (Hextend or albumin) ex- Plasma-Lyte 0.9%
5
perimental trials exist with the Buddy Lite at this time. 148 Saline PRBCs FFP
2mL/min flow at
• Saline. At 5°C input saline temperatures, the Buddy Lite 60-min duration 6,027.9 80.1 72.8 61.8
heated saline to a combined average output temperature 16mL/min flow at
of 31.8°C for all flow rate groups (25–100mL/min). At 60-min duration 658.0 N/A N/A N/A
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10°C input saline temperatures, the Buddy Lite failed to PRBC = packed red blood cell; FFP = fresh frozen plasma.
achieve >36°C output temperatures at flow rates above
50mL/min. In terms of effective saline volume warmed, Thermal Angel. Manufacturer recommendations state the
6–8
the Buddy Lite failed to effectively warm any measurable device can warm IV fluids and blood for flow rates up to
amount of volume with 10°C input saline temperatures at 150mL/min. The Thermal Angel is the only device to have
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100mL/min. 8 trialed saline, colloid, and blood.
• Blood. A single study measured outlet temperatures with
expired whole blood cooled to 9.5°C at 50mL/min. The • Saline. For 20°C input saline temperatures at 100mL/min,
Buddy Lite warmed expired whole blood to 35.2°C. 9 the Thermal Angel produced an average output temperature
• Time to Peak Heating, Maximum Flow Rates, and Battery of 36.4°C. In terms of effective volume of saline warmed,
8
Characteristics. The Buddy Lite reaches time to peak heat- the Thermal Angel could only heated 0.98L to nearly 36°C
ing in 263.5 and 270.8 seconds with 20°C and 5°C input before its battery depleted. For 10°C input saline tempera-
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saline at fixed flow rates (30, 50, and 100mL/min). Maxi- tures at 100mL/min, the Thermal Angel warmed 0.8L to
6
mum flow rates through a 14-gauge PIV pressurized system an average output temperature of 29.4°C. The Thermal
8
(274–374mmHg) yields 330mL/min and 390mL/min. The Angel failed to effectively warm cold lactated Ringer’s
8
Buddy Lite’s battery capacity measures at 89 watt-hours (4–7°C) at 180mL/min, but warmed cold LR to 33–34°C
(wh). In one study, experimenters infused 4–5L of cooled at 140mL/min. 13
saline, and the device struggled to generate stable thermal • Colloids and Blood. The Thermal Angel achieved >33°C
outputs until 30 minutes lapsed. 8 average temperature output for cold (4–7°C) PRBCs
• enFlow. Manufacturer recommendations state the heating and 6% Hextend at low flow rates (~60mL/min), and
element can warm IV fluids from to keep open (TKO) to >35°C for PRBCs and cold Hextend at higher flow rates
Army Deployment IVF Warmers: Literature Review | 11