Page 41 - JSOM Winter 2023

Tightening System Total Times
The fastest times from “touch tightening system” to “first oc- Total stopwatch times for each tourniquet during applica-
clusion” were applications that achieved a tight strap during tions were well matched with total times as determined via
the strap/redirect system part of the application (Figure 3 and frame-by-frame capture from video (Figure 5, each tourniquet
Table 1). Understanding the tightening system and not having correlation coefficient >0.99). Stopwatch times were always
problems such as losing hold of the windlass rod were also slightly longer, with <0.91 seconds as median differences from
associated with faster times to “first occlusion.” Separate first frame-by-frame for each tourniquet.
and last occlusions happened with windlass rod tourniquets
(6 CAT7, 8 SOFTTW3, 10 SOFTTW5, and 11 TMT) and one Discussion
X8T application. Separate first and last occlusions were not
restricted to applications that lost hold of the windlass rod or Key findings were as follows: 1) Process problems (see com-
redid windlass rod turning. panion paper ) were associated with slower strap/redirect sys-
1
tem times and slower tightening system times. 2) Achieving
Only windlass rod tourniquets had tightening system securing good strap tightness in the strap/redirect system part of the
struggles and a lack of tightening system security (Figure 4). application process is not slower than achieving bad strap
Times from “touch tightening system” to “Done” and from tightness. 3) Achieving good strap tightness in the strap/redi-
“occlusion” to “Done” were faster for each of the self-securing rect system part of the application process is associated with a
tightening systems than for any of the windlass rod tightening shorter duration of tightening system use. 4) The fastest strap/
systems, even when only comparing windlass rod tourniquet redirect systems had clips and were self-securing. 5) The fastest
applications without rod securing struggles (Figure 4, Figure tightening systems were self-securing.
5, and Table 1). Among applications that were occluded at
“Done” and had secure tightening systems, those that achieved Our data support the expectation that understanding prob-
a tight strap during the strap/redirect system part of the ap- lems and physical problems during the strap/redirect system
plication generally had faster “touch tightening system” to part and the tightening system part of the application process
“Done” times than applications that did not achieve a tight slow applications down. This increases the time from picking
strap during the strap/redirect system part of the application up a tourniquet to stopping bleeding and therefore to doing
(Figure 5 and Table 1). any other tasks such as managing other injuries or helping
other casualties. This means understanding and physical pro-
Among good orientation applications that were not occluded cess problems that are not necessarily directly associated with
at “Done” because the applier prematurely stopped using the lower rates of reaching occlusion or tourniquet security are
1
1
tightening system, median times from “touch tightening sys- still important to consider when making tourniquet choices.
tem” to “Done” were not significantly faster than occluded at
“Done” times for all tourniquet applications except those of The strap tightness from strap/redirect system use affects the
the TMT (Figure 5). results of tightening system use. This was already shown with
prior generations of CATs with regards to tourniquet damage
Among the windlass rod tourniquet applications that had the and the amount of tightening system use required for occlu-
tightening system secured as directed and were occluded at sion. 19-22 Data in the companion to this paper show not achiev-
“Done,” “touch tightening system” to “Done” times were sig- ing good strap tightness in the strap/redirect system part of
nificantly faster for the SOFTTW5 (median 10.55, interquar- the application process is associated with tightening system
tile range [IQR] 7.87–16.69 seconds) than the SOFTTW3 failure to achieve occlusion and problems with tightening
(median 13.16, IQR 10.22–24.45 seconds, p=.036). Tight- system security for tourniquets besides the CAT7. Our time
1
ening system secured as directed for the SOFTTW5 in this data indicate not achieving good strap tightness also lengthens
study was placement of the windlass rod in the bracket and the duration of tightening system use. Because not achieving
did not require rod securing in the triangle. (Bracket only good strap tightness is not faster than achieving good strap
securing is not medically appropriate and was only allowed tightness, not achieving good strap tightness increases time to
to assess difficulty imposed by the triangle; securing in the occlusion and to application completion. Therefore, any tour-
triangle is required for clinical applications.) In addition to niquet application instruction should include the importance
differences in the incidence of struggling to secure the rod, of achieving good strap tightness before using the tightening
1
the time difference between the SOFTTW3 and SOFTTW5 system, 1,19-22 optimal pulling technique concepts for achieving
supports placement of the rod in the securing triangle as good strap tightness, 23,24 and achieving visible skin indentation
less easy and more time-consuming than placement in an as a necessary marker of good strap tightness. 24
open-top bracket. Among applications that were occluded
at “Done,” the longest “touch tightening system” to “Done” A high rate of good strap tightness is a positive aspect of sim-
times belonged to the unidirectional, side-opening bracket of ple redirects; however, current simple redirect designs involve
1
the TMT (median 16.81, IQR 11.26–30.65 seconds, n=34 hook-and-loop straps and are not self-securing. Self-securing
tightening system secured and 18.61, 13.12–27.66 seconds, strap redirect buckles have the benefits of not requiring ap-
n=11 not secured). Times from “touch tightening system” to pliers to properly secure the strap (one less step and one less
“Done” for the CAT7 were longer when the windlass rod possible problem ), allowing additional pulling to potentially
1
was correctly secured in the top-open bracket with overlying incrementally tighten the strap, no need for hook-and-loop on
hook-and-loop straps than when it was not correctly secured the strap with its opening and pulling interference potential
(median 14.47, IQR 10.47–18.12 seconds, n=17 tightening (two fewer possible problems ), and, at least when combined
1
system secured and 11.90, IQR 8.08–13.53 seconds, n=35 with a clip, faster times from picking up a tourniquet to use of
not secured). the tightening system.

Tourniquet Processes Times | 39