Page 53 - JSOM Fall 2025

FIGURE 4 Times for first and last tourniquet applications.
A video orientation for the graphs can be accessed at https://vimeo.com/898205889/2a5ead48e4? In each panel, the y-axis shows time in seconds;
the x-axis lists tourniquets; first applications are indicated by light color open circles; last (seventh and eighth) applications are indicated by
dark color open diamonds; experienced applications are blue (with blue center dots if by the three OMT-only experienced), and no-experience
applications are red. (A) Times from the director saying “Go” to “strap secured;” p=.008 first no-experience versus last no-experience, p=.089
first no-experience versus first experienced, p>.847 first experienced versus last experienced, and last experienced versus last no-experience.
(B) Times from “touch tightening system” to either the applier saying “Done” or being stopped by the director; p=.236 first no-experience versus
last no-experience, p=.486 first no-experience versus first experienced, p>.994 first experienced versus last experienced, and last experienced
versus last no-experience.
(A) 300 (B)
275
250 1st set experienced (seconds) 300
(seconds) 130 last sets experienced 100 1st set experienced
250
140
(with dot OMT-only)
(with dot OMT-only)
90
(with dot OMT-only)
last sets experienced
120
1st set no experience
80
(with dot OMT-only)
last sets no experience
110
70
Secured" 100 to "Done" 60 1st set no experience
last sets no experience
50
90
45
80
40
70
to "Strap 60 35
30
50
40
25
"Go" 30 "Touch Tightening System" 20
20
15
10 10
0 5
CAT7 SOFTTW3 SOFTTW5 TMT OMT X8T Tac RMT RST 0 CAT7 SOFTTW3 SOFTTW5 TMT OMT X8T Tac RMT RST
per applier, too few occurred with the simple redirects of the SOFTTW5 time of 21.41 seconds and a second-encounter,
CAT7 and OMT to allow assessment of any impact of first sixth- application SOFTTW3 time of 266.20 seconds (applier’s
versus second encounters (one minor OMT problem by a physical problem with the clip led to redirect rethreading). The
no-experience applier). Median “Go” to “strap secured” times other outlier broke the SOFTTW5 redirect in the first appli-
for experienced appliers were 21.91 seconds first encounter cation, first encounter (300 seconds assigned) and had a time
and 24.99 seconds second encounter (p=.6541). For no-ex- of 55.72 seconds for the second-encounter, fourth-application
perience appliers, when excluding both times for the outlier SOFTTW3 (p=.514 when not excluding those times). (That
with a first-encounter CAT7 time of 262.47 seconds (first ap- SOFTTW5 redirect was pre-production; the problem cannot
plication) and a second-encounter OMT time of 34.05 sec- occur with the production version.)
onds (sixth application), median times were 30.12 seconds
first encounter and 25.88 seconds second encounter (p=.0005; Tightening-System-Understanding Problems
p=.098 when not excluding those times). In first and last applications by experienced appliers, tightening-
system-understanding problems only occurred once: last ap-
For the highly similar, shared-strap/redirect designs with clips of plication by an OMT-only experienced applier (#7) who
the SOFTTW3 and SOFTTW5, no strap/redirect-understanding repeatedly engaged the RST releasing mechanism with the
problems happened with experienced appliers. Median “Go” advancing lever (suboptimal mechanical design). In first and
1
to “strap secured” times for experienced were 22.01 seconds last applications by no-experience appliers, tightening-system-
for first encounter and 20.97 for second encounter (p=.545). understanding problems occurred five times: three first appli-
Among no-experience appliers, there were 14 SOFTTW3/ cations and two last applications (3 of 30 no-experience first
SOFTTW5 first-encounter strap/redirect- understanding prob- versus 1 of 10 experienced first applications, p=.560; 3 of 30
lems and 10 SOFTTW3/SOFTTW5 second-encounter strap/ no-experience first versus 2 of 65 no-experience last applica-
redirect-understanding problems, six of which were with appli- tions, p=.322, Figure 5B).
ers with a first-encounter problem, indicating lack of first-use
learning with the SOFTTW3/SOFTTW5 strap/redirect system Regarding highly similar, shared-tightening-system-design fea-
(14 of 33 first versus 10 of 33 second encounters, p=.443; 14 tures and tightening-system-understanding problems in any
of 33 first versus 4 of 16 second encounters without a first- application per applier, experienced appliers had no tighten-
encounter understanding problem, p=.137). ing-system-understanding problems with any windlass-rod
tightening system. One no-experience applier had tightening-
For no-experience appliers and clips of the SOFTTW3 and system-understanding problems with first- and second-
SOFTTW5, median “Go” to “strap secured” times were encounter windlass-rod tightening systems (first and third
31.22 seconds first encounter and 21.95 seconds second en- applications, CAT7 and SOFTTW3). One no-experience ap-
counter (p=.079) when excluding both times for the two out- plier had a tightening-system-understanding problem with
liers. One outlier had a first-encounter, fourth-application their third-encounter windlass-rod tightening system (seventh

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