Page 52 - JSOM Summer 2019

smooth metal rod (4.20cm diameter), and the seated applier 1. strap-pulling force applied tangential to the gel surface at
held onto the free end of the C-A-T7 strap and pulled down to the redirect buckle (0° angle),
lift the attached weights. Appliers were encouraged to engage 2. strap-pulling force applied directly outward from the gel
their entire upper body strength and weight into the down- surface at the redirect buckle (90° angle), and
ward pull. 3. strap-pulling force applied directly outward from the gel
surface at the redirect buckle (90° angle), followed by
Thigh Tourniquet Applications gel rotation to a strap-pulling force tangential to the gel
Mid-thigh applications had the redirect buckle on the lateral surface at the redirect buckle (0° angle).
side midway between the anterior and posterior aspects of the
thigh, with the redirected strap hanging downward. Six ap- For the tangential-only pulling force, each end of the gel was
plication techniques were explored, leading to the use of four held so the redirect buckle remained lateral, midway between
application techniques by all appliers. Each thigh-application the top and bottom of the cylinder with the strap traveling
technique consisted of a tourniquet-holding location and a downward from the redirect buckle parallel to the portion of
strap-pulling direction. Strap holding was always done with the strap entering the redirect buckle (tangential to the gel at
the nondominant hand, strap pulling with the dominant hand. the redirect buckle). This position was maintained through-
The two techniques that were so ineffective they were only out weight attachment, 200 seconds of weight hang, weight
used once were holding above the redirect buckle and pulling removal, and subsequent determination of the secured strap
the strap only directly outward from the limb (90° angle) and pressure. For the directly outward-only pulling force, the gel
holding below the redirect buckle and pulling the strap only was allowed to remain in a redirect buckle toward the floor
directly outward from the limb (90° angle). The four tech- orientation throughout weight attachment, 200 seconds of
niques used by all appliers were the following: weight hang, weight removal, and subsequent determination
of the secured strap pressure. For the outward followed by tan-
1. holding above the redirect buckle and pulling the strap gential pulling forces, 200 seconds of directly outward pulling
downward, tangential to the limb at the redirect buckle (0° force were followed by gel rotation to the tangential pulling
angle); force position followed immediately by weight removal and
2. holding below the redirect buckle, trying to feed the strap subsequent determination of the secured strap pressure. Be-
into the redirect and pulling the strap downward, tangen- cause the C-A-T7 and TMT are not self-securing, the hook-
tial to the limb at the redirect buckle (0° angle); and-loop of their straps was engaged before weight removal.
3. holding above the redirect buckle and pulling the strap
directly outward (90° angle) and then pulling downward, Statistical Analysis
tangential to the limb at the redirect buckle (0° angle); For thigh applications, the order of tourniquet and of tech-
and nique were counterbalanced to avoid a potential effect on
4. holding the redirect buckle and pulling the strap directly results. Numeric pressure data were organized in Microsoft
®
outward (90° angle) and then pulling downward, tangen- Office Excel 2003 (Microsoft Corp., www.microsoft.com).
tial to the limb at the redirect buckle (0° angle). Graphing and statistical analyses were performed with Graph-
Pad Prism, version 7.04 for Windows (GraphPad Software
Appliers were allowed to move the strap side to side during Inc., www.graphpad.com). Graphs show all data points plus
pulling to aid strap movement through the redirect buckle. For boxed quartiles (thigh data, box and whisker with scatter
outward pulling techniques, appliers were allowed to repeat graph) or medians (gel data). Two-way analysis of variance
the outward then downward pulling up to three times. was used with technique and tourniquet pressure data. χ test
2
was used for frequency data. Statistical significance was set at
The locations used when holding above the redirect buckle p ≤ .05.
varied according to tourniquet design. For the C-A-T7, TMT,
and SOFTTW, the windlass-securing bracket or clip or trian- Results
gle was used for holding above the redirect buckle. For the
Tac RMT and Parabelt, the built-in holding loop was used for Appliers
holding above the redirect buckle. Fourteen appliers were female (six experienced, five novice,
and three complete novice), and six were male (three experi-
The location used for all tourniquets when holding below enced, one novice, and two complete novice). Three females
the redirect buckle was the strap on the ventral surface of the were 56, 58, and 59 years old. The other appliers ranged from
thigh. The strap was held between the first two fingers and 18 to 22 years old (median, 20 years).
thumb of the nondominant hand. The two fingers were be-
tween the strap and thigh during strap holding. Applier Pulling Force
Single-arm downward pulling force ranged from 13.84 to
Gel Tourniquet Applications 50.29kg. The frequency of each pulling force was as follows:
Gel applications were mid-cylinder with at least 30 minutes 13.84kg, one applier (experienced); 18.41kg, six appliers (three
of rest time between applications. Gel tackiness prevented experienced, two novices, one complete novice); 23.06kg, six
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tourniquets from sliding around the cylinder, so no tourniquet appliers (two experienced, two novices, two complete novices);
holding was used. Gravity acting on 23.06kg attached to the 27.64kg, two appliers (one experienced, one complete nov-
end of the strap provided the strap-pulling force of 226N ice); 32.28kg, three appliers (one experienced, two novices);
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(50.84lbf) for all applications on the gel (23.06kg was the me- 41.50kg, one applier (experienced); and 50.29kg, one applier
dian pulling force of the appliers). (complete novice). For all appliers, for each experience-based
group of appliers, and for the 14 women, the median pull was
Three application techniques were used with the gel: 23.06kg. The median pull for the six men was 29.96kg.

50 | JSOM Volume 19, Edition 2 / Summer 2019