Page 42 - JSOM Winter 2023

Regarding clips versus strap rethreading through the redirect encountered. Failure to understand key concepts and optimal
buckle, clip systems had the fastest “Go” to “touch tightening techniques does not generally equate with the best outcomes
system” individual and median times for all and problem-free when people are faced with physical tasks that require some
applications. Not all clips are equivalent: clip recognition deviation from how the task was done in a controlled setting.
problems were prevalent with the TMT and non-existent with
the X8T, and unclipping/reclipping problems were the least Limitations
frequent with the SOFTTW5, though the most frequent with This study has the limitations associated with the pre-study de-
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the similar clip of the SOFTTW3. Unthreading and rethread- cisions detailed in the discussion section of the companion pa-
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ing of a self-securing redirect buckle was not as fast as unclip- per. In addition to the shared limitations, collecting time data
ping and reclipping a self-securing redirect buckle and offered related to specific design features requires discrete, identifiable
the unfortunate opportunity for rethreading problems. 1 starting and stopping actions for those features. This resulted
in times for use of the entire strap/redirect system without sep-
Time from “touch tightening system” to “occlusion” was faster arate times for clip use. Another limitation-imposing choice
with windlass rod systems, but “touch tightening system” to was what to do regarding times for event failures. Not includ-
“Done” was faster with self-securing systems by a larger mar- ing a time for an event failure would result in misleadingly fast
gin and avoided questionable rod security issues. Additionally, times for that tourniquet for that event; therefore, we chose to
34 windlass rod system applications that did not involve a use 300 seconds, the maximum allowable application time as
tightening system understanding problem had variable length the time for event failures.
occlusion losses between achieving occlusion and completing
the application. These occlusion losses are indicated by sepa- Conclusions
rate first and last occlusion times (Figure 3, differences from
0.13 to 73.41 seconds). In 18 applications, the occlusion losses Suboptimal tourniquet application processes increase applica-
were associated with losing hold of the rod or resetting the tion times. Suboptimal strap tightness from the strap/redirect
rod. Other causes of these occlusion losses were the backward system part of the application process negatively affects all as-
movement of the rod during the securing process and the time pects of the tightening system use part of the application pro-
spent achieving rod securing. Beyond the faster tightening cess. Among nonelastic, non-pneumatic emergency-use limb
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system completion times and prevention of rod security is- tourniquets, optimal design features for fast, occlusive, secure
sues, two additional advantages to the self-securing tightening tourniquet applications are self-securing strap/redirect systems
systems would be the finer resolution securable pressure in- with an easily identifiable and easily used clip and self-secur-
crements and the ease of additional tightening whenever indi- ing tightening systems.
cated with no need to un-secure and then resecure a windlass
rod with the additional risk of releasing the tightening system Acknowledgments
because of rod slippage. The authors thank the following Drake University undergrad-
uates of the Trauma Research Team for their help carrying out
From our results concerning scoring and timing the processes the experiments: Jared Defriend, Mikayla Soelter, Amanda
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involved in tourniquet application around a “trapped” limb, Gregory, Bryan Williams, Mia Fidanze, Erin O’Keefe, Quynh
we conclude the following: 1) For nonelastic, non-pneumatic Pham, Lindsey Skerrett, Kristen Skriver, Erin Steffenson, Dani
emergency-use limb tourniquets, the best combination of Eernisse, Jack Libbesmeier, Kayla Markuson, Taylor Rent-
design features for most frequently achieving the fastest oc- schler, and Stephanie Richardson.
cluded and secure tourniquet applications would be an easily
identified and used clip, a self-securing strap redirect buckle Disclosures
(unidirectional friction would be preferred but is not a cur- None of the authors have any financial relationships relevant
rent tourniquet option to our knowledge), and a self-securing to this article to disclose, and there was no outside funding.
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tightening system (either parallel to the limb dial rotation or As indicated in the methods of the companion paper, tourni-
perpendicular to the limb buckle advancement on a ladder). 2) quets were requested from manufacturers or distributors, and
Tourniquet training for the public should include tourniquets seven of the eight models of tourniquets were donated. PW,
with clips, self-securing redirect buckles, and self-securing CB, and JD are paid by their respective institutions, and the
tightening systems. Teaching and supplying only windlass rod other authors were volunteer researchers. None of the authors
style tourniquets for public “Stop the Bleed” kits is subopti- has stock in any tourniquet companies, and none do any paid
mal if maximizing the percentage of applications that are oc- consulting with any tourniquet companies. The authors talk
clusive, secure, and fast is desired. 3) When strap rethreading to and share data with any and all companies and individuals
can happen, a diagram of the rethreading should be placed who are interested and do not keep any secrets. The lab equip-
on the strap because once the strap has been unthreaded, the ment belongs to Drake University and UnityPoint Health Iowa
threading pattern can no longer be seen to be copied. 4) For Methodist Medical Center.
individuals supplied with a specific tourniquet, training should
include avoiding errors that are easy, common, or important Author Contributions
with that specific tourniquet (examples, failure to open all the PW and CB contributed to concept development and project
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hook-and-loop of the TMT, failure to correctly secure the design. All authors contributed to the acquisition, analysis,
windlass rod of the CAT7, or grasping the releasing mech- and interpretation of data and the drafting and revising of the
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anism of the RST during tightening ). 5) Training for people article. All authors had final approval of the manuscript.
who might encounter any type of tourniquet should empha-
size key concepts. Educating potential tourniquet users on key References
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concepts and optimal techniques is more likely to allow users 1. Wall P, Buising B, Jensen J, et al. Effects of tourniquet features on
to achieve the best applications allowed by the circumstances application processes. J Spec Oper Med. 2023;23(4):11–30.
40 | JSOM Volume 23, Edition 4 / Winter 2023