Page 11 - JSOM Spring 2023

Warning

Tourniquets Risk Frostbite in Cold Weather

John F. Kragh, Jr, MD *; Daniel K. O’Conor, MD 2
1

ABSTRACT
We sought to better understand the frostbite risk during first- environmental circumstances. 13–15 Frostbite can only occur
aid tourniquet use by reviewing information relevant to an when the environmental temperature is <0°C (<32°F). 16
association between tourniquet use and frostbite. However,
there is little information concerning this subject, which may Climate change trends in global warming may lead one to think
be of increasing importance because future conflicts against that military services will be operating in warmer environments.
near-peer competitors may involve extreme cold weather en- That is true globally on average, but it also suggests a paradox-
vironments. Historically, clinical frostbite cases with tourni- ical consequence: Warm trends risk cold conflicts. For example,
quet use occurred in low frequency but in high severity when warming has resulted in the melting of arctic ice. With reced-
17
leading to limb amputation. The physiologic response of ing sea ice, competition for natural resources in arctic areas is
vasoconstriction to cold exposure leads to limb cooling and likely to increase, such as for previously inaccessible oil reserves
causes a reduction of limb blood flow, but cold-induced va- where national boundaries remain disputed. Sea lanes across the
sodilation ensues as periodic fluctuations that increase blood Arctic Ocean are opening, and their use can cut ocean transit
flow to hands and feet. In animal experiments, tourniquet use times and distances while avoiding fees at the Panama and Suez
increased the development of frostbite. Evidence from human Canals, but these sea lanes are largely in Russian waters, and the
experiments also supports an association between tourniquet Russian government has become increasingly hostile. 18,19 These
use and frostbite. Clinical guidance for caregiving to casualties facts increase the likelihood that US forces will be deployed to
at risk for frostbite with tourniquet use had previously been colder areas of the world for peacekeeping, disasters response,
provided but slowly and progressively dropped out of doc- and other national security operations. Given developments in
uments. Conclusions: The cause of frostbite was deduced to the US arctic strategy, 19,20 cold-weather training operations may
be a sufficiently negative heat-transfer trend in local tissues, increase, especially with allies and partners. Medical personnel
which tourniquet use may worsen because of decreasing tissue planning for cold-weather operations should emphasize preven-
perfusion. An association between tourniquet use and frostbite tion of cold injury, prepare to care for traumatic injuries in cold
exists but not as cause and effect. Tourniquet use increased the weather, and plan to treat individual casualties with both a cold
risk of the cold causing frostbite by allowing faster cooling of injury and a traumatic injury.
a limb because of reduced blood flow and lack of cold-induced
vasodilation. Care providers above the level of the lay public Most tourniquet uses have not occurred in extreme cold
are warned that first-aid tourniquet use in low-temperature weather, an operational environment to which militaries have
(<0°C [<32°F]) environmental conditions risks frostbite. recently returned their attention. 19,21–23 While most of the re-
cent conflicts involving the US Military have occurred in warm
Keywords: bleeding control and prevention; first aid; pre- environments, future conflicts against near-peer competitors
hospital care; freezing cold injury; complication; wounds might occur more frequently in extreme cold weather environ-
and injuries ments, making considerations of possible side-effects of tour-
niquet use timely. In military operations conducted in extreme
cold weather, frostbite can be common, 24–26 disabling, 27–31
costly, 28,32,33 and, if inappropriately managed, potentially le-
Introduction
thal. 35–39 Tourniquet use in war has been reported to be associ-
In common emergencies when a need arises to stop limb- ated with subsequent frostbite injury among many cases that
1–3
wound bleeding, tourniquet use has lifesaving benefits. 1,8,9 had limb loss by surgical amputation. 39–41
4–7
When blood flow to a limb is stopped, convective heat flow
is also stopped. 10–12 Loss of such a heat input carried by blood We sought to better understand the frostbite risk during first-
permits the limb tissue to cool toward a lower ambient tem- aid tourniquet use by reviewing information relevant to this
perature or warm toward a higher one, depending on the association. We use the term “tourniquet-hastened” frostbite
*Correspondence to 3698 Chambers Pass, Joint Base San Antonio Fort Sam Houston, TX; or john.f.kragh.civ@health.mil
1 Dr Kragh is a health scientist of hemorrhage control in the Department of Hemorrhage and Vascular Dysfunction at the Institute of Surgical
Research, Fort Sam Houston, San Antonio, TX, and an associate professor in the Department of Surgery, Uniformed Services University of the
2
Health Sciences, Bethesda, MD. Capt O’Conor is a resident in the Department of Emergency Medicine at the Brooke Army Medical Center, Fort
Sam Houston, San Antonio, TX.
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