Page 29 - Journal of Special Operations Medicine - Fall 2017

the glove types, and the study procedures, and was present for Beforehand, a few traits of gloves were thought to likely affect
assessments and supervised testing. The users were given the performance. A caliper was used to measure the thicknesses
opportunity to be familiarized with the use of the tourniquet, of glove groups. Thickness measurement did not include gaps
which included the user reading the hardcopy instructions for between layers, such as between the outer surface of the cold
use, watching the online video instructions, handling the tour- gloves and the inner surface of the mittens. Our focus was
niquet, becoming familiar with technique, and preparing the to discern whether the surfaces of hands or the surfaces of
tourniquet for use. Tourniquet use was deconstructed and the gloves worked well or were troublesome, along with the gaps
first step, unwrapping the tourniquet from its plastic wrapper, between surfaces. Furthermore, the bagginess of gloves, the
was the focus of the test performed in this study. Because the tackiness of surfaces, and workability of gloves were thought
context of the study was related to the assessment of perfor- to be potentially impactful. Interfaces included the skin surface
mance but not to training, the assessor did not give real-time of the user’s hand, the inner surface of the glove group, the
feedback directly to the user until after each test was both outer surface of the glove group, and the tourniquet surface.
completed and assessed. Layered systems had the added interfaces of the outer surface
of the inner layer and the inner surface of the outer layer. Gaps
Initially, tourniquets packaged in the wrapper were placed in- included the air space between the hand and glove, and the air
dividually on the table. The user donned the gloves by glove space between the glove and tourniquet. Layered systems had
group, which was randomized. When the user was ready, he the added gap between the outer surface of the inner glove and
let the assessor know. The assessor gave the start command, the inner surface of the outer glove.
and the user gave the stop command after the tourniquet was
unwrapped, unrouted, pulled out to length, and laid flat on To assess advice about environmental exposure, an exposure
the table. The process of “unrouting” was simply the removal portion of this study was of tourniquet devices placed on a roof
of the band from its course through a slit in the buckle. Un- in San Antonio, Texas, for 3 months in the summer of 2016.
routing is a step in tourniquet use when the user needs to The devices were organized by version of model, direction
remove the free end of band from the buckle to run the free of exposure, and state of wrapping. Two versions were stud-
end circumferentially around a limb and back into the slit ied to see if exposure effect varied from one version to other,
in the buckle. This specific step is to be made in treating an two directions (up-down) were assessed to see if sunlight was
entrapped limb. This unwrapping-to-laid-flat procedure was impactful, and wrapper status (present-absent) was assessed
meant to be a surrogate of a clinically relevant procedure to see if the wrapper protected tourniquets from exposure ef-
(i.e., a step in the treatment of an entrapped limb), which may fects. Furthermore, devices were studied if only certain com-
be plausibly challenged by handling of the tourniquet while ponents degraded. There were 12 exposed tourniquet devices,
gloved. in six pairs. The first three pairs were C-A-T generation 6
devices and the second three pairs were C-A-T generation 3
The success in unwrapping meant that the tourniquet was devices. The two generations were laid out similarly, but the
unwrapped, unrouted, and laid flat. After testing, comments pairs were put into reversed directions of exposure to make a
of the user were offered, solicited, and recorded. The asses- matched up-down pairing with bands up or down. The band
sor queried uncertain actions or unclear words to gain clarity up meant that the red tip and smooth backside of the band
and then asked about ease of use, problems, missteps, glove were up toward the sun while the windlass rod, the windlass
traits, or strategies to mitigate risk. The feedback between the clips, and the stabilization plate were down toward the roof.
user and the assessor was mainly verbal and included point- The direction of the other device in the pair was reversed.
ing out specific features of the tourniquet, the wrapper, or the The first pair of each generation was laid out as wrapped; the
gloves, but occasionally included physical demonstration of tourniquet remained routed and configured. A second pair of
technique, hand position, or tourniquet alignment. The feed- each generation was laid out like the first pair, but the second
back especially emphasized what the user was trying to do to was unwrapped. The third pair of each generation was laid
tackle an emerging problem that might have caused a slow or out like the second pair, but its band was unrouted to lay
a complicated performance. flat. The self-adhering band includes the Omni-tape brand
fasteners as a single-component Velcro brand of hook-and-
The overall number of uses (replicates) was 36 for the study. loop fasteners with alternating rows of hooks and loops on
Four users unwrapped one tourniquet device for one test each one side of the fabric so it can fold over and attach to itself.
among the nine groups of gloves. Each user had nine tests, These fasteners are made of nylon (a synthetic semi-aromatic
whereas each device was subjected to one test. The perfor- polyamide polymer) and polyester (a polyethylene terephthal-
mance was assessed during the use of both the glove group and ate polymer).
the tourniquet device; therefore, for an individual test, there
was no capacity for statistical differentiation between the user, The 12 exposed devices were checked on the roof at weeks 2
the glove group, or the device used, because the intervention and 6, and at the end of week 13, when they were returned to
required all three acting together. However, looking at all tests the laboratory. Of the 12 devices, two were flipped over (likely
allowed analysis of user effects and of glove effects. by wind): one unrouted generation 3 device found at week
2 (when it was flipped back over) and one unrouted genera-
The performance results were summarized by each outcome tion 6 device found at week 6 (when it was flipped back over).
(i.e., metric of performance), by glove group, and by user. The
success in unwrapping was the primary outcome as a binary Descriptive statistics were used to portray results. Continu-
variable (yes-no, unwrapped). The secondary outcomes in- ous data (i.e., time to unwrap) were summarized by median
cluded time to unwrap and damage (yes-no) to tourniquet or (range) or mean (standard deviation), which were analyzed
gloves. Time to unwrap (in seconds) was the main continuous using analysis of variance (ANOVA). Fixed-effect tests were
metric of performance. made by glove group. Dunnett’s method was used to calculate

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