Page 27 - JSOM Winter 2023

occlusion; 3) Self-securing systems lead to fewer opportuni- Key Finding 1
ties for tourniquet security problems; 4) Including tourniquet Tourniquets can be grouped according to design features (Fig-
security rather than only evaluating occlusion results in major ure 1), but differences among conceptually similar features
differences in how ideal a tourniquet would be considered. The have substantial impacts on how successful appliers with lim-
time-related aspects of this study will be discussed in the com- ited training will be. For example, the seemingly minor differ-
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panion paper following this article in this journal. ences in strap materials and slider redirect buckles between
the SOFTTW3 and SOFTTW5 resulted in significant differ-
Before discussing the key findings, it is important to note that ences in strap tightness before tightening-system use. Among
we made several pre-study decisions related to what questions the different styles of clips, the TMT clip was much harder
we wanted to explore: for appliers to recognize than other clips. Between the two
double redirect tourniquets, some appliers seemed confused
1) We showed only one orientation for tourniquet applica- regarding where to pull the X8T but not the RST. Therefore,
tion: lateral redirect buckle with strap pulling downward. while conceptually grouping tourniquets has its uses, it must
We consider this orientation preferable because it provides be done with caution and consideration of the finer points
more applier working space than does working between and end goals of the discussion for which the groupings are
the recipient’s legs, it also offers the opportunity to engage made. For example, grouping all tourniquets into either wind-
the applier’s body weight in strap pulling, and it puts tight- lass rod or non-windlass rod tightening systems is likely to
ening systems in an accessible location. be inappropriate for reaching optimal decisions regarding
2) We folded and oriented each tourniquet as similarly to each what tourniquets are ideal for community-accessible bleeding-
other as possible rather than presenting each tourniquet as control kits and classes. Additionally, when exploring if train-
packaged by the manufacturer. This was to compare the ing with one windlass rod tourniquet, such as the CAT, assists
impact of design feature differences rather than the impact with use of a different windlass rod tourniquet, such as the
of manufacturer-presentation choice differences. SOFTTW3, one should consider differences in how easily
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3) We showed SOFTTW5 application completion as windlass optimal strap-pull-related tightness is reached and how easily
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rod placement in the bracket without adding the triangle. the windlass rods are secured, otherwise one risks mistaking
This allowed investigation of securing-difficulty differences differences in physical properties for failure to learn general-
between the triangle (SOFTTW3) and open-top bracket izable knowledge.
(SOFTTW5) of two very similar tourniquets but is not a
clinically appropriate application completion; in real use, Key Finding 2
the rod of the SOFTTW5 should be secured in the trian- Appliers knew applications were being timed and were in-
gle. Our results indicate that placement of a windlass rod structed to “do your best to be quickly correct with each of
in an open-top bracket (CAT7 and SOFTTW5) is physi- your tourniquet applications” (Appendix A). Appliers clearly
cally much easier than placement in a securing triangle wanted to finish applications as quickly as possible. In some of
(SOFTTW3) or the side opening of a unidirectional bracket the 55 applications in Figure 5 in which tightening stopped too
(TMT). However, an open-top bracket may require an ad- soon, occlusion was present when active tightening stopped
ditional step for security. but did not persist through “hands off the tourniquet” and
4) We used a tightening-system-use-at-occlusion threshold to stating “Done.” In many of those instances, appliers clearly
define optimal pull-related strap tightness. The need for wanted to recall the utterance and perform additional tight-
fewer than three 180° rod turns as optimal has been estab- ening. This may have been most common with the X8T be-
lished for the CAT for structural reasons 42-44 and appears cause appliers tended to maintain some hand pressure on the
reasonable for SOFTTWs and TMTs for rod securability dial between clicks. The best approach for avoiding the prob-
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reasons. Defining optimal pull-related tightness with the lem was full “hands off,” followed by a listening pause, then
X8T, OMT, Tac RMT, and RST is harder. Each has finite either resumption of tightening or stating “Done.” Such an
tightening capacity. With the X8T, we chose less-than- or- approach traded adding time for assurance of occlusion and
equal-to one 180° dial rotation from the starting position was not common. Even one very experienced applier made the
as optimal (10 clicks). With the Tac RMT, fewer than eight “stopped too soon” mistake with an X8T application. Fewer
tooth advances for occlusion corresponds with pull-related applications would have failed to be occluded at “Done” if
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strap pressures that would be acceptable for the CAT and appliers had been allowed to change their minds regarding
are achievable. Because the tooth advances of the OMT being done. We believe being timed influenced some appliers
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and RST are larger than those of the Tac RMT, we set the against taking the time for a listening pause (most inexperi-
definition of optimal tightness for those two tourniquets at enced appliers probably would not have known the usefulness
one click less than for the Tac RMT. of a listening pause).
5) We did not instruct appliers to advance ratcheting-
tightening systems an additional click past occlusion. This Before using the tightening system, appliers interacted with
allowed instructional consistency across tightening systems: the strap/redirect system. Appliers demonstrated a variety of
tighten to Doppler signal loss then secure the tightening mistakes with strap/redirect systems. Only a few problems pre-
system, which means stop tightening when using a self- cluded occlusive applications: pulling at the wrong location,
securing system. For clinical use, we strongly recommend improper rethreading, and pulling so poorly that a finite tight-
at least one additional advance beyond occlusion with any ening system could not overcome the bad pull. Unexpected
fine-resolution, self-securing tightening system. 40,41 strap problems were two appliers managing to unthread the
6) We decided “Done” would be a final statement with no ad- earlier generation TMT and two appliers managing to have
ditional applier-tourniquet interaction allowed after stating occlusive TMT applications without ever opening all the inte-
“Done.” rior strap hook-and-loop.

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