Page 38 - JSOM Summer 2023

Efficacy of the Military Tactical Emergency Tourniquet
for Lower Extremity Arterial Occlusion Compared with the
Combat Application Tourniquet

A Randomized Crossover Study

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Disney K. Samutsakorn, MPAS ; Brandon M. Carius, DSc, MPAS *
1

ABSTRACT
Introduction: Extremity bleeding and subsequent hemorrhagic and international forces, is recommended by CoTCCC and is
shock is one of the main causes of preventable battlefield often used as the prototype for comparison with newer, un-
death, leading to mass-fielding of modern tourniquets, such tested models. 2,5–9
as the Combat Application Tourniquet (CAT; Composite Re-
sources). Numerous look-alike tourniquets, such as the Mil- The current CAT design centers on a single-looped hook-and-
itary Tactical Emergency Tourniquet (MTET; SZCTKlink), loop fastening strap, which is further tightened by turning
flood commercial markets, offering visually near-identical a thick plastic windlass rod. Repeated studies have demon-
tourniquets for drastically reduced prices. We examined the strated effective measured occlusion by the CAT in simulated
performance of the MTET compared with that of the CAT. injuries. 5,6,8 Still, over the past two decades, numerous tourni-
Methods: We undertook a randomized crossover trial to ob- quets have entered the commercial market, many using some
serve self-applied tourniquets to the lower extremity by com- variation of the Spanish windlass, with varying degrees of
bat medics, comparing the CAT to the MTET in application success, and others using different mechanisms. More recently,
time and success rates, proven by loss of distal pulse assessed however, several companies abandoned attempts to devise
by Doppler ultrasound in <1 minute. Results: All 50 partici- a novel tourniquet and instead directly replicated the well-
pants (100%) successfully applied the CAT versus 40 partici- known design of the CAT. 10–12 These primarily appear to come
pants (80%) using the MTET (p = .0001). Median application from international companies but are sold on the Internet
time for the CAT (29.03 seconds; range, 18.63 to 59.50 sec- and marketed in English to potential American customers. 11,12
onds) was significantly less than those of successful MTET Many of these are nearly identical to the CAT in terms of both
applications (35.27 seconds; range, 17.00 to 58.90 seconds) the mechanism of action and general appearance but with no
or failed MTET applications (72.26 seconds; range, 62.84 to clear evidence of efficacy or product quality.
83.96 seconds) (p = .0012). Of 10 MTET failures, three (30%)
were from application time >1 minute and seven (70%) from The MTET is a CAT look-alike, both in general appearance
tourniquet mechanical failure. Conclusion: The MTET per- and mechanical design. It is sold individually at online retailers
formed worse than the CAT did in all observed areas. Despite for approximately half the cost of the CAT ($16.99 vs. $30),
identical appearance, look-alike tourniquets should not be as- and a three-pack can be purchased for $23.59, or less than
sumed to be equivalent in quality or functionality to robustly one-third the cost of the three CAT devices (Figure 1). The
tested tourniquets. MTET has thousands of reviews on the Amazon website and
is listed as “Amazon’s Choice” in the tourniquet category. The
Keywords: education; hemorrhage; bleeding control manufacturer of MTET has little public company information
to be found through online searches but is listed as a registered
13
trademark of the Tianke Electronics. The company offers a
Introduction wide range of products, including electronics cables, record
players, smartphones, socks, and dog whistles. 13
Hemorrhage control is a central intervention of prehospital
medicine, initially from findings of disproportionate prevent- Visual similarities (Figure 2), substantail price markdowns,
able deaths and now as the opening focus in military care and the advertised equivalency of imitation tourniquets such
guidelines, including recommendations from the Commit- as the MTET offer a compelling inexpensive alternative for
tee on Tactical Combat Casualty Care (CoTCCC) and Joint budget-concerned military units and prehospital providers.
Trauma System. Development and implementation of mod- The market for imitation tourniquets has increased substan-
1–4
ern tourniquets generally center on vasculature constriction tially (to include the MTET, introduced within the past three
through circumferential limb pressure, which is then ampli- years), and military budgets have become tighter. Although
fied through mechanical advantage by a secondary mecha- imitation devices offer a budget-friendly option, they remain
nism, such as a windlass or ratcheting lever. One of the earliest largely untested compared with the robust body of studies into
modern tourniquets, the CAT, fielded throughout American the efficacy of CoTCCC-recommended tourniquets. 2

*Correspondence to brandon.m.carius.mil@health.mil
2
1 CPT Disney K. Samutsakorn is affiliated with Brooke Army Medical Center, Joint Base San Antonio–Fort Sam Houston, TX. MAJ Brandon M.
Carius is affiliated with Madigan Army Medical Center, Joint Base Lewis–McChord, WA.
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