Page 48 - JSOM Fall 2025

Across Tourniquet Designs First-Use Learning

Piper Wall, DVM, PhD *; Charisse Buising, PhD ;
1
2
Catherine Hackett Renner, PhD 3

ABSTRACT
Background: We hypothesized shared-design tourniquet fea- tightening system involving rotation parallel or perpendicular
tures have useful first-use learning when knowledge-of-results to the limb surface. Depending on knowledge-of-results feed-
occurs. Methods: In a prior study, after watching training vid- back, we believe use of a tourniquet with a design feature sim-
eos, 64 volunteers were videoed applying (Latin squares ran- ilar to that of a different tourniquet (a shared general design
domization): Combat Application Tourniquet Generation 7 regarding that feature) will result in first-use learning relevant
®
(CAT7), SOF Tactical Tourniquet-Wide Generation 3 to that part of the different tourniquet, even in the absence of
®
(SOFTTW3), SOF Tactical Tourniquet-Wide Generation 5 instructor-origin feedback. If true, this suggests even limited
®
(SOFTTW5), Tactical Mechanical Tourniquet (TMT), OMNA training with tourniquets with different strap/redirect-buckle
™
Marine Tourniquet (OMT), X8T-Tourniquet (X8T), Tactical systems and different tightening systems may increase appli-
®
Ratcheting Medical Tourniquet (Tac RMT), and RapidStop cation success if faced with a new tourniquet (such as might
™
®
Tourniquet (RST). Tourniquets were applied to live thighs with be the case with public access bleeding control kits or with
audible distal Doppler pulses. Results: This study subset was someone else’s first aid kit).
10 experienced and 33 no-experience appliers. Experienced
appliers had fewer strap/redirect and fewer tightening- system When tourniquets are applied to live humans in practice set-
understanding problems and faster associated times than tings, some application aspects directly provide appliers with
no-experience appliers. Among no-experience appliers, first- knowledge-of-results information and some aspects do not.
use learning was supported by faster “Go” to “strap secured” Examples of knowledge-of-results information present with-
times for combined seventh and eighth versus first applications out instructor-origin feedback include: limb encirclement with
(p=.008), second- versus first-encounter CAT7/OMT applica- the tourniquet, presence or absence of some degree of strap
tions (p=.0005), and second- versus first-encounter SOFTTW3/ security around the limb, movement of aspects of the tight-
SOFTTW5 applications (p=.079). Occlusion at “Done” was ening system, presence or absence of increasing tourniquet
more frequent with experienced appliers (p=.006) and did not tightness around the limb, presence or absence of some de-
show first-use learning across all tourniquets in no-experience gree of tightening-system security, and presence or absence of
appliers. Occlusion at “Done” indicated possible first-use learn- a distal pulse if a monitoring technology such as audible Dop-
ing with ratcheting-buckle versus windlass-rod tightening sys- pler is involved. Examples of knowledge-of-results feedback
tems (p=.028, no-experience appliers). Hook-and-loop strap likely to require instructor involvement include: idealness of
security, which provides no inherent knowledge-of-results, placement location, movement patterns, strap tightness before
showed no learning in experienced (five problem applications tightening-system use, strap security, and tightening-system
by two appliers) or no-experience appliers (29 problem applica- security.
tions by 18 appliers). Conclusions: Knowledge-of-results is crit-
ical for, but does not guarantee, tourniquet-application- useful The study purpose was to look for first-use learning regard-
first-use learning. The existence of first-use learning can allow ing shared general design features of several emergency-use
limited experience with one tourniquet to improve performance limb tourniquets. First-use learning would be demonstrated
with a different tourniquet with shared-design features. There- by increases in process speed and decreases in understand-
fore, exposure to different designs may have value, and provid- ing problems. The hypotheses were, in the absence of any
ing tourniquet-training knowledge-of-results is important. instructor-origin feedback: some first-use learning would oc-
cur regarding similar strap/redirect systems, similar tightening
Keywords: tourniquet; hemorrhage; first aid; emergency systems, and achieving audible Doppler signal loss, and no
treatment; learning first-use learning would occur regarding hook-and-loop strap
security and different windlass-rod securing systems.

Introduction Methods
Many emergency-use limb tourniquets are commercially avail- Data presented is a subset from a Drake University Institutional
able. Most have some version of the following design features: Review Board-approved study. Methods are detailed in two
a limb-encircling nonelastic strap, strap-redirecting buckle, and papers: one concerning evaluation of tourniquet application
*Correspondence to piperwalldvm@gmail.com
2
1 Dr. Piper Wall is a researcher in the Department of Research, UnityPoint Health Iowa Methodist Medical Center, Des Moines, IA. Dr. Charisse
Buising is a professor of biology at Drake University, Des Moines, IA. Dr. Catherine Hackett Renner is a volunteer researcher at UnityPoint
3
Health Iowa Methodist Medical Center, Des Moines, IA.
46