Page 77 - JSOM Fall 2025

in a basin, and the desired ingredients are placed in a vacu- are limited full-text studies evaluating the device’s effectiveness.
um-sealed bag and stabilized within the bath. There are many However, according to a poster presentation and abstract from
commercially available devices with varying specifications. FreMon Scientific, a study was conducted comparing specific
Depending on the temperature setting and water circulator plasma assays between the ZipThaw 202 versus a standard
usage, the sous vide uses 800–1200W. Once the target tem- water bath method, and the study concluded no significant
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perature is reached, power requirements decrease significantly. differences in measured post-thaw clotting parameters. The
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The sous vide does not require additional accessories besides a study did not report measured FFP mean thaw times.
water basin, although overwraps are recommended to reduce
the risk of bacterial contamination. The Barkey Plasmatherm Classic and its updated Plasma-
therm V model is another dry-based plasma thawing system
The sous vide can heat and maintain up to 98L of water to that uses two heated water bladders. At 37°C, researchers
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a maximum temperature of 92°C. Recommended basin size demonstrated thaw times of 30 minutes for four units of FFP
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ranges from 5.6 to 19.6L. With pre-warmed water heated to per cycle and another study demonstrated a thaw time of ap-
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37°C, a sous vide has been shown to thaw two units of FFP proximately 32 minutes for 3–4 units of FFP. 15,16 Two stud-
in 28.1 (SD 2.4) minutes. Thaw times average 35.0 (SD 6.6) ies evaluated thawing kinetics with the Plasmatherm V set to
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minutes when water is not pre-warmed. FFP thawed using a 45°C and achieved thaw times between 10 and 14 minutes for
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sous vide has shown no statistically significant difference in four units of FFP. 17,18 Chapman et al. attempted to outfit am-
coagulation factor preservation compared to FFP thawed with bulances with the Plasmatherm for pre-hospital FFP thawing,
a standard clinical plasma thawer. 6 but the large power consumption from the device damaged the
ambulances’ charging systems. 19
The sous vide may offer additional utility beyond thawing
frozen blood products. Currently, there is only one published Radio Wave Thawing Methods
study to date that explores potential treatments for cold The microwave oven has been used in laboratory settings to
weather injuries, such as hypothermia and frostbite, using thaw FFP since the 1970s. Microwave ovens heat food, or in
a temperature-controlled circulating water bath with a sous this case FFP, using microwaves, a form of electromagnetic
vide. The researchers thawed a frozen steak from –1.1°C to radiation like radio waves. An available FDA-approved mi-
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37°C in 52 minutes using an improvised 40°C water bath. crowave oven option is the ARK Biomedical Plasma Defroster
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Additionally, the 40°C heated water warmed 3.9°C normal (ARK Bio-Medical Canada Corp., Dartey Estate, Prince Ed-
saline (1L) to 40°C in 10 minutes and warmed 3.9°C WB ward Island) which has a maximum power consumption of
(450mL) to 34°C in 10 minutes. Lastly, it was noted that 1800W. 21
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the sous vide was also able to maintain a water temperature
of 40°C for up to 3 weeks in a 12°C simulated Role 2 tent. 11 FFP thaw times were variable with different commercially
available microwave ovens. These thaw times ranged from
Flameless Ration Heater 4 to 19 minutes. 18,22–28 The differences in this time range can
The U.S. Army Flameless Ration Heater, known as the MRE be explained by researchers modifying frozen plasma units in
heater, is a reported method to achieve a non– temperature- a flattened configuration, modifying microwave ovens to in-
controlled thaw of FFP. Most MRE meal options contain one clude elements that rotate the FFP, and manual agitation of
chemical heating element. The heater is activated when 30mL the FFP unit during short-burst thaw sessions. These modifi-
of water contacts its powder-based heating element. Research- cations were made because of researchers’ attempts to avoid
ers tested two configurations for thawing FFP using MRE thawing an area of the FFP too rapidly in microwaves due to
outer packaging, MRE heaters, and variable amounts of wa- uneven heating delivery, sometimes referred to as hot spots.
ter; the MRE heaters could not successfully thaw FFP. 6 These hot spots may compromise coagulation factor viability,
degrade proteins, or damage FFP bags.
Dry-Based Thawing Methods
Dry-based thawing methods differ from water-based thawing Discussion
methods since the unit of FFP does not make direct contact
with heated water. Rather, the unit of FFP is typically placed The Helmer QuickThaw is FDA-approved and widely used by
between self-contained bladders that contain either heated conventional U.S. Army medical units, but its use is limited for
water or heated water-based liquid. An internal heating ele- ARSC teams. The DH8 and DH4 models have large operating
ment controls the bladder temperature, which then thaws FFP footprints, which create challenges for teams that must remain
through heat transfer. Integration of internal temperature sen- highly mobile. In contrast, the DH2 model is compact and uses
sors allows for target temperature-controlled regulation. low power, but it can only thaw two FFP units simultaneously
and requires additional accessories for safe operation, which
ZipThaw 202 (Fremon Scientific Inc., La Jolla, CA) is a may not always be accessible in far forward environments.
™
dry-based, temperature-controlled method of FFP thawing.
The device can thaw two units of FFP at a time, with an ideal Currently, no published case studies exist relating to field-
unit size of 250mL each. The ZipThaw 202 has two cham- adapted plasma thawers being used in battlefield operations.
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bers, each using 400W of power combined for 800W. The However, the authors acknowledge that unpublished anecdotal
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ZipThaw 202 requires ZipSleeve enclosure bags around each experiences exist with varying degrees of success and should
®
FFP unit for operation. therefore warrant further discussion. Desirable characteristics
of an optimal field-adapted plasma thawer are those that can
The ZipThaw 202 is reported to thaw a unit of 250mL FFP in create a temperature-controlled water bath, are energy efficient,
approximately 16 minutes. The device contains sensors that lightweight, durable, portable, and demonstrate favorable thaw
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do not allow FFP temperatures to increase above 37°C. There kinetics with acceptable post-thaw coagulation preservation.
Alternative Plasma Thawers | 75