Page 34 - Journal of Special Operations Medicine - Winter 2015

bandage, muslin, compressed, camouflaged; National www.chisystems.com) that was designed to train users
Stock Number 6510-00-201-1755; approximately $3.65 by providing feedback on user performance; the right-
each). The bandage can be used also as an arm sling, side thigh had an above-knee amputation injury. 29,30 An
as a wrap, and as an adjunct to splinting. The bandage embedded computer had a smartphone-like touchpad
used was olive drab, and the dimensions of its triangular integral to the thigh (software version 1.9; CHI Sys-
perimeter were 37, 37, and 52 inches. One bandage was tems). The manikin was operated by user input through
used for all tests in the bandage group. finger touch on the pad. The manikin’s thigh was placed
on a laboratory bench and was operated in accordance
The second improvised technique involved using a ban- with the manufacturer’s instructions. The thigh did not
dana as the strap: this is a common practice among Co- bleed; rather, bleeding was represented by red lights that
lumbian Special Forces soldiers. The bandana used in transilluminated the wound. The number of lights illu-
the present study was a 35 × 35-inch square cloth made minated represented the bleeding rate—all 26 lights on
of cotton (Extra X-large bandana, Giant-danna, Hav- meant maximal bleeding; no lights on meant bleeding
a-Hank ; Fendrich Industries; http://www.carolinamfg. had stopped. A few lights twinkling indicated intermedi-
®
com). The bandana comes folded into a square, but was ate control. Arterial pulses were palpable in the popliteal
used as a triangle (34 × 34 × 49 inches), folded diago- area. Touchpad readouts included hemorrhage control,
nally into the same width as the US Army bandage. One the time of application, the pressure exerted under the
bandana was used for all tests in the bandana group. tourniquet, and the simulated blood loss volume. Itera-
tions began with a tourniquet laid out undone (unpack-
The windlass used for the two improvised techniques aged, folded, flattened, and stretched out lengthwise) on
was made of chopsticks. Eight common, bamboo chop- the bench and not yet applied to the thigh. The time of
sticks were taped together in a group. Previously, we application was designated to be that time interval be-
had determined that six taped chopsticks worked well tween the beginning of an iteration and the time point
and a chopstick rarely broke within the group after re- at which the manikin detected that no more blood was
peated use in laboratory testing (M. P. Altamirano et al., lost. Once the manikin detected the cessation of blood
personal communication, 2014). However, to eliminate loss, the tourniquet was considered to be effective. In
all breakage, we used eight instead of six chopsticks. cases where the user could not make the tourniquet ef-
The chopsticks were 21cm long, and the masking tape fective despite repeated attempts, the user terminated
was wrapped twice around the group 4cm from either the test. The casualty had a medium build and the set-
end of the chopsticks. This one windlass was used for all ting was care under fire, an emergency setting wherein
tests of the two improvised techniques (i.e., the bandage the casualty and caregiver are in danger (e.g., ongoing
group and the bandana group). gunfire).

The control group was the standard-issue Combat Ap- The manikin settings also included a constant hemor-
plication Tourniquet (CAT; Composite Resources; rhage rate (635mL/min). The resulting bleed-out time
®
http://combattourniquet.com); we used the current ver- was 4 minutes—240 seconds to successfully apply the
sion, which is known as CAT Generation 6. One CAT tourniquet if there was no hemorrhage control at all.
was used for all tests. There is already a large body of Time periods with intermediate hemorrhage control,
knowledge concerning the performance of the CAT. 16,27,28 even interspersed among periods with no hemorrhage
control, could yield longer bleed-out times before the
There were two users testing the tourniquets. One user casualty status became “dead.”
was a clinician-scientist with extensive tourniquet expe-
rience, including tourniquet care, research, and devel- Results were summarized by various outcomes for each
opment. The other user was a US Army Special Forces group. The critical outcome was effectiveness (hemor-
nonmedical officer. The order of testing by user was rhage control, yes/no). An important outcome (a sec-
clinician-scientist then Soldier. ond, independent measure of effectiveness) was absence
of palpable pulse distal to the tourniquet (yes/no). Sec-
Sixty tests were conducted. There were two users, three ondary outcomes included time of application, pressure
groups of tourniquets (CAT, bandage, and bandana), and applied to the skin by the tourniquet, and the simulated
10 tests per group per user. The order of testing by group volume of blood loss. Turn numbers were the number of
for both users was the CAT group, the bandage group, windlass turns required to tighten the strap; 180° was
and then the bandana group; each group was completed a turn, since field users call that a turn. Effectiveness,
by the user before the next group was started. time of application, and pressure were measured by the
manikin, while turn numbers and pulse cessation were
The tourniquets were tested on a laboratory manikin measured by the user. Tourniquets, users, tests, and out-
(HapMed Leg Tourniquet Trainer; CHI Systems; http:// comes were uniquely identified.
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22 Journal of Special Operations Medicine Volume 15, Edition 4/Winter 2015