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to indicate that tourniquet use does not cause frostbite but There were very few reports found of cases with an association
that it can quicken the development of frostbite and increase between tourniquet use and frostbite. Only Böhler’s textbook
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its incidence. This is not a systematic review of science: To the had “many cases.” The clinical cases found primarily occurred
first-aid community, it is a warning. in large-scale combat operations. Because wounding and frost-
bite totaled 1% in two different war samples, 43,44 we deduced
Tourniquet-Hastened Frostbite Cases Occur that 1% is a rough guess of a maximum rate of potential tour-
in Low Frequency but are High Severity niquet-hastened frostbite cases. Tourniquet-hastened frostbite
Frostbite cases with tourniquet use were reported in both cases occurred at low frequency, while many had high severity
World Wars by an Austrian surgeon, Lorenz Böhler, who spe- because limbs were amputated. The information indicated that
cifically recognized that tourniquet use risked frostbite and tourniquet-hastened frostbite cases can exist, but detection, re-
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later limb loss. He noted little in his orthopedic textbook cording, and reporting has been limited, in part because of diffi-
about first-aid tourniquets in the cold: culties of documentation during war or limited awareness of the
potential association between tourniquet use and cold injury.
When a limb is constricted, the nourishment obtained
through the blood stream is shut off, and if the constric- Clinical Tourniquet Uses to
tion is maintained for several hours, the extremity must Cool Limbs in Amputation Surgery
die. This danger is greater in wintertime. In both World Tourniquets have been used in surgical studies of hospitalized
Wars, I saw many limbs needlessly constricted, which patients with severely diseased limbs to reduce risks associ-
were frozen during transport because of the use of a tour- ated with anesthesia or the amputation itself. 52,53 This method
niquet, and which had to be amputated. 39 of amputation includes isolating a limb with tourniquets, fol-
54
lowed by freezing with ice, and then surgery. The cessation of
Likewise, at the Battle of the Bulge in World War II, a Soldier blood flow was an important factor in determining how thor-
reported himself as a tourniquet-hastened frostbite case. In oughly 55,56 and how fast a limb was chilled. A report advised
55
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a large sample of 1,450 battle casualty deaths of US Service caregivers to protect the other limb from iatrogenic cold and
Members in World War II studied, only eight had frostbite or warned that limbs and icing should be carefully monitored by
other cold injury as a contributory or associated condition nursing and medical personnel. These recommendations im-
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identified at autopsy. Among these deaths, a small propor- ply that thermal management of diseased limbs requires skill
tion, 1% (8/1,450), had a nonbattle cold injury and a battle and vigilance to minimize complications and that achieving
wound—for example, a casualty having combined injury optimal care entails a caregiving workload to improve aware-
mechanisms: frostbite and gunshot wound. In a Korean War ness, train personnel, assess patients, monitor treatments, and
sample of US combat casualties surviving to military hospital troubleshoot problems. Altogether, these surgery reports in-
admission in Japan, very few (1%) battle-wounded casualties dicate that tourniquets might reliably hasten and deepen the
had an associated cold injury, but this accounting was made chilling of limbs by the speed and magnitude of cooling.
at a US military hospital in Japan on a ward of principally
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frostbite cases. Those more seriously wounded in Korea were The Physiologic Response to
segregated to other wards and hospitals and lost to frostbite Cold Exposure Leads to Limb Cooling
accounting, despite some potentially having been frostbitten. Investigators have studied 10,57–60 and reviewed 61–65 how cold
Thus, the author of this study noted a likely undercounting exposure affects limbs. Important factors responsible for en-
44
of associated war wounds among the frostbite cases and also vironmental cooling to result in frostbite include ambient air
did not note tourniquet use. 25,44 In Korea, two nonfiction his- temperature, the rate of air movement, and duration of expo-
torical books specifically note combined injury mechanisms of sure. Upon exposure of the body to cold, a series of physi-
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cold injury with battle wound in individual casualties, but no ologic responses occurs that is thought to reduce the risk of
tourniquet use was noted. 45,46 In Korea, there were two docu- hypothermia in the body’s core. 61,67 The initial mechanism of
mented tourniquet-hastened frostbite cases, each reported by cold-induced vasoconstriction is a sympathetically mediated
the casualty himself. 47–49 reflex. Skin temperature of the fingers and toes was reported
65
to rapidly and exponentially decrease over time to a level ap-
A report of a 1962 airplane crash had a case of tourniquet use proaching that of the ambient environment. 64
in which the Soldier froze to death, but there was too little
50
detail provided to posit a potential association. In our search Vasoconstriction profoundly decreases blood flow. For exam-
of these early cases, we found no case reported of a person ple, when a human arm was immersed in cold water, a rapid
who froze to death while a limb tourniquet remained applied. fall of deep-muscle temperature resulted from the greatly de-
Perhaps to observers present at the death, tourniquet use may creased blood flow, which at a water temperature of 13°C to
have become unimportant to the situation at hand. 20°C (55.4°F to 68°F) became sometimes almost impercepti-
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ble. Vasoconstriction of blood vessels in the cold tissues had
In recent combat operations, tourniquet use has been com- essentially stopped blood flow. 58,62,68
1–3
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mon while frostbite has not. A 2010 study reported 19
cases of cold-weather injury identified in the Afghanistan The heat conductivity of the skin increased with depth from
conflict; only two of these included frostbite; no mention was the skin surface and with the amount of blood flow for acral
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made of tourniquet use. In 2022, we asked the Department parts, such as fingertips. 15,69,70 Vasoconstriction during core hy-
of Defense Joint Trauma System (https://jts.health.mil/) for a pothermia was reported as sufficiently strong to reduce heat
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preliminary count of registrant cases of either limb frostbite flow to <0.1W, meaning that flow effectively stops.
or tourniquet use, and 14 frostbite cases and 7,510 tourniquet
cases were documented from 2002–2021. Among cases, none In 1946, investigators used a venous tourniquet effect of
had both conditions recorded. a plethysmograph to measure hand blood flow while a
10 | JSOM Volume 23, Edition 1 / Spring 2023