Page 85 - JSOM Summer 2020

Clothing Effects on Limb Tourniquet Application

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Piper Wall, DVM, PhD *; Charisse Buising, PhD ; Emma Hingtgen, BS ;
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Hailey Smith, BA ; Catherine Hackett Renner, PhD 4
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ABSTRACT
Background: Sometimes tourniquets are applied over clothing. Methods
This study explored clothing effects on pressures and appli-
cation process. Methods: Generation 7 Combat Application The Drake University Institutional Review Board approved
Tourniquets (C-A-T7), Generation 3 SOF Tactical Tourni- this prospective study, which took place October 2018 through
®
quets–Wide (SOFTTW), Tactical Ratcheting Medical Tourni- April 2019.
quets (Tac RMT), and Stretch Wrap And Tuck Tourniquets
(SWATT) were used with different clothing conditions (Bare, The Generation 7 C-A-T (C-A-T7, Lot 121K177; C-A-T Re-
Scrubs, Uniform, Tights) mid-thigh and on models (ballistic gel sources, http://combattourniquet.com/), was purchased. One
®
and yoga mats). Results: Clothing affected pressure responses Generation 3 SOF Tactical Tourniquet – Wide (SOFTTW;
to controlled force applications (weight hangs, n=5 thighs and manufactured 3 April 2017, 11 January 2019, 14 January
®
models, nonlinear curve fitting, p < .05). On models, cloth- 2019; Tactical Medical Solutions, www.tacmedsolutions
ing affected secured pressures by altering surface interactions .com) was purchased; two were donated. Tactical Ratcheting
®
(medians: Gel Bare C-A-T7 247mmHg, SOFTTW 99mmHg, Medical Tourniquets (Tac RMT; 10 November 2015; m2 Inc.,
Tac RMT 101mmHg versus Gel Clothing C-A-T7 331mmHg, www.ratchetingbuckles.com) were donated. Stretch Wrap
SOFTTW 170mmHg, Tac RMT 148mmHg; Mats Bare C-A-T7 And Tuck Tourniquets (SWATT; Lot# J068287, manufactured
246mmHg, SOFTTW 121mmHg, Tac RMT 99mmHg versus 5 January 2018, H & H Medical Corp., www.swattourniquet
Mats Clothing C-A-T7 278mmHg, SOFTTW 145mmHg, Tac .com) were donated.
RMT 138mmHg). On thighs, clothing did not significantly in-
fluence secured pressures (n=15 kneeling appliers, n=15 stand- Tourniquets
ing appliers) or occlusion and completion pressures (n=15). The 3.8cm-wide nonelastic tourniquets were the C-A-T7,
Eleven of 15 appliers reported securing on clothing as most dif- SOFTTW, and Tac RMT. The C-A-T7 has a hook-and-loop
ficult. Fourteen of 15 reported complete applications on cloth- strap, non-self-securing redirect buckle, and windlass tighten-
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ing as most difficult. Conclusions: Clothing will not necessarily ing system. The SOFTTW has a smooth strap, self- securing
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affect tourniquet pressures. Surface to tourniquet interactions slider redirect buckle, and windlass tightening system. The
affect the ease of strap sliding, so concern should still exist as Tac RMT has a smooth strap, self-securing overlapping-
to whether applications over clothing are dislodged in a distal rectangles redirect buckle, built-in holding loop above the re-
direction more easily than applications on skin. direct buckle, and self-securing ratcheting buckle on a toothed
ladder tightening system. The SWATT is a 10.4cm-wide by
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150cm-long elastic tourniquet that is not self-securing.
Keywords: tourniquet; hemorrhage; first aid; emergency
treatment
Pressure Measurements
Pressures were measured using a neonatal blood pressure cuff
(2.2cm × 6.5cm bladder, single tube) at 18mmHg above at-
Introduction
mospheric pressure (baseline). The bladder was on the me-
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Limb tourniquet placement over clothing risks missing inju- dial thigh under the tourniquet (approximately 180° from the
ries and is associated with looseness, risking ongoing bleeding redirect buckle C-A-T7, SOFTTW, Tac RMT). The bladder
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and venous occlusion without arterial occlusion. To avoid was connected to a Vernier Gas Pressure Sensor, Vernier Lab-
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these problems, Tactical Combat Casualty Care (TCCC) Pro interface, and Logger Pro Software (Vernier Software and
guidelines recommend limb tourniquet application on skin un- Technology, www.vernier.com). Pressures were recorded every
less providing Care Under Fire. 3 second for hanging weights and completed application trials,
and every tenth of a second for trials ending after the strap was
Many clinical and staged pictures of tourniquets applied over secured. During experiments, appliers did not receive informa-
clothing exist in research literature and tourniquet-training- tion regarding pressures.
associated videos. The study purpose was to explore clothing
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effects on thigh tourniquet application. The hypotheses were Tourniquet Recipients
clothing could affect the application process, pressure mea- Tourniquets were applied mid-thigh. Inclusion criteria were
surements, and tourniquet pressures. age ≥ 18 years, systolic blood pressure < 140mmHg, and no
*Correspondence to piperwall@q.com
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1 Dr Wall is a researcher in the Surgery Education Department, UnityPoint Health Iowa Methodist Medical Center, Des Moines, IA. Dr Buising
is a professor of biology and the director of the Biochemistry, Cell and Molecular Biology Program, Drake University, Des Moines, IA. Ms
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Hingtgen and Ms Smith were undergraduate students at Drake University. Dr Renner is associate vice president of Analytic Support and Insti-
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tutional Research, Grinnell College, Grinnell, IA.
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