Page 56 - JSOM Fall 2025

application, CAT7). Times were not compared because differ- four eighth applications. Seven of the 15 appliers lacked oc-
ences in rod securing systems would also influence times from clusion in only one application, three in two, three in three,
“touch tightening system” to “Done.” one in four, and one in five applications. Regarding the four
highly similar, windlass-rod tightening systems with different
When considering any ratcheting-buckle-tightening-system ap- rod- securing designs, four of the 15 appliers lacked occlusion
plication per applier, understanding problems only occurred twice and one lacked occlusion three times. Regarding the
once with an experienced applier (#7, RST, detailed previously). three highly similar, ratcheting-buckle tightening systems, one
Median “touch tightening system” to “Done” times for experi- of the 15 appliers lacked occlusion twice (1 of 15 ratcheting
enced were 10.19 seconds first encounter, 8.27 seconds second versus 5 of 15 windlass, p=.169).
encounter, and 6.98 seconds third encounter (p=.336 first versus
second, .189 first versus third, and .302 second versus third). Regarding all 33 no-experience appliers and excluding appli-
Among no-experience appliers, ratcheting-buckle- tightening- cations with system event failures, windlass-rod applications
system-understanding problems occurred twice on first encoun- lacked occlusion at “Done” more frequently than ratcheting-
ter (Tac RMT, OMT), twice on second encounter (RST, RST), buckle applications (23 of 106 windlass-rod versus 7 of 88
and twice on third encounter (OMT, Tac RMT). One of the ratcheting-buckle applications, p=.028). The frequency of re-
third-encounter problem applications was the same applier as peated non-occluded applications in no-experience appliers
a second-encounter problem application, and the same applier indicates the absence of sufficient across-tourniquet-designs,
had understanding problems with windlass-rod tightening sys- technique-useful, first-use learning from audible Doppler sig-
tems in two applications. For no-experience appliers, when ex- nal knowledge-of-results feedback to increase the rate of oc-
cluding all times for the three applications with event system clusion success with dissimilar designs.
failures and the one application in which the recipient called a
stop, median “touch tightening system” to “Done” times were Strap Security at “Done”
8.07 seconds first encounter, 9.35 seconds second encounter, Hook-and-loop-associated strap security did not show evi-
and 9.03 seconds third encounter (p=.248 first versus second, dence of first-use learning (Figure 5D). Among experienced
.969 first versus third, and .192 second versus third). appliers, inadequate strap hook-and-loop engagement was
present in one first application (#47, TMT), one second ap-
Occlusion at “Done” plication (#54, TMT), one seventh application (#47, OMT),
At “Done,” occlusion was not present four times with expe- and two eighth applications (#47, CAT7 and #54, OMT).
rienced appliers. One was a third application: SOFTTW3 by Among no-experience appliers, 29 applications lacked strap
an OMT-only experienced applier with Doppler sound return security because of inadequate strap hook-and-loop engage-
after their hands came off the tourniquet while already say- ment and five lacked strap security because of a strap/redirect-
ing “Done.” Two were fifth applications: one SOFTTW5 by understanding problem.
an OMT-only experienced applier with a faint Doppler sound
that may not have been audible to the applier; one X8T by an Among the hook-and-loop-securing-adequacy-problem ap-
OMT-only experienced applier with Doppler sound return as plications, six were first applications, five were second, two
the hands came off the tourniquet (had already said “Done”). were third, six were fourth, three were fifth, three were sixth,
The fourth was a seventh application: X8T by an applier four were seventh, and none were eighth applications. In
experienced-with-all-eight-tourniquets, had Doppler sound re- no- experience appliers, eight had hook-and-loop securing-
turn as their hands came off the tourniquet; they had already adequacy problems in only one application, nine had them in
said “Done,” Figure 5C. two, and one had them in three applications.

Lack of occlusion at “Done” was more common among no- Tightening-System Security at “Done”
experience appliers (45 of 264 no-experience applications Windlass-rod security did not show evidence of first-use
versus 4 of 80 experienced applications, p=.006 and p=.030 learning (Figure 5E). Among experienced appliers, four had
when excluding eight no-experience applications with inadequate CAT7 rod security: three failed to place the cir-
occlusion- preclusive events) but did not show a change indi- cumferential strap over the rod in the bracket (#6 first appli-
cating first-use learning from knowledge-of-results feedback cation, #47 eighth application, and #54 fourth application);
(no-experience 2 of 29 first versus 11 of 65 last applications two failed to place the time strap across the bracket (#54
when excluding applications with occlusion-preclusive events, fourth application and #3 seventh application). None of the
p=.332, Figure 5C). experienced appliers had rod-security problems with other
windlass-rod tightening systems.
Strap/redirect-understanding failures precluded reaching oc-
clusion in three first, one sixth, and one seventh application. Among no-experience appliers, 36 applications had inade-
Inadequate strap pulling precluded reaching occlusion in one quate rod security: 24 CAT7 and 12 TMT. The CAT7 applica-
fifth application (same applier as the seventh application strap/ tions were two second, three third, two fourth, six fifth, five
redirect-understanding problem). Tightening-understanding sixth, four seventh, and two eighth applications. The CAT7
failures precluded reaching occlusion in one first and one third errors were two failures to position the rod in the bracket (one
application (same applier, both windlass-rod applications). Of with no straps placed, one with time strap placed), 10 failures
these six appliers, four had one additional application that to place both the circumferential strap over the rod in bracket
lacked occlusion at “Done,” and one had two that lacked and time strap over the bracket, 12 failures to place the cir-
occlusion at “Done.” Among the remaining 216 applications cumferential strap over the rod in bracket but time strap was
by the 27 other no-experience appliers, 31 applications by 15 placed over the bracket, two failures to place time strap across
appliers lacked occlusion at “Done:” two first, five second, bracket containing rod and circumferential strap. The TMT
five third, four fourth, two fifth, three sixth, six seventh, and applications were two first, one second, two third, two fourth,

54 | JSOM Volume 25, Edition 3 / Fall 2025