Page 121 - JSOM Summer 2020

Considering all of this, Montgomery et al. rated this model at where it had not only lower occlusion pressures in both upper
40.31, with the most points being deducted for decreased sim- and lower extremities but also fewer failures than either of the
plicity of use compared with the CAT, but regardless granting other models. 35
it CoTCCC approval. Therefore, even though the TMT can
11
achieve vessel occlusion and is recommended by the CoTCCC, The ability of the SWAT-T to maintain a consistent pressure
the layperson should be educated about the potential for ex- was further illustrated by Rometti et al., which attributed this
cessive pressure and slower application. ability to its elastic recoil properties. In their study, the SWAT-T
and CAT were both applied at the same occlusive pressure and
Elastic-type Tourniquets reassessed at 5 and 10 minutes afterward, and while the CAT
Besides windlass-type models, there are also elastic-type tour- lost 68mmHg of pressure, the SWAT-T only lost 13mmHg.
43
niquets available for use by the public that function through The prior pediatric study by El-Sherif et al. also considered
sequential wrapping to constrict and apply pressure for ves- the SWAT-T, and favored its flexibility as it was able to ac-
sel occlusion. One such is the broad-based SWAT-T, which commodate any diameter of PVC pipe as well as any limb of
is applied by stretching out the tourniquet and wrapping the the 1-year-old and 5-year-old mannequins. However, rather
injured limb as many times as possible, with the free end be- than being limited by circumference, the SWAT-T was instead
ing tucked underneath the most superficial layer of tourniquet limited by extremity length, as the wide length of the elastic
to secure tension (Figure 6). 18,40 Montgomery et al. rated the precluded the ability to isolate a specific location on the limb.
SWAT-T at 28.13 due to discrepancies in occlusion, applica- This increased the risk of applying pressure both below the
tion speed, simplicity in use, and device safety, and as such it is wound and on top of a joint. While these studies seem prom-
31
not CoTCCC recommended. This lower rating is well illus- ising, the failures seen in the JOEFT should not be discounted,
11
trated by the findings of the JOEFT, which also evaluated the and thus the layperson should be educated about the SWAT-
SWAT-T along with the aforementioned windlass-type tour- T’s potential for malfunction and longer application.
niquets. Whereas these tourniquets were successfully applied
in phase I, the SWAT-T failed to achieve occlusion in 70% Another wrap-style tourniquet is the IST, also known as the
of attempts, and took on average three times as long to be “Israeli Bandage.” To apply this tourniquet, a tail of about
applied. It was also found to be inferior in phase II, where in 30cm should remain outside the first wrap, which should be
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contrast to the majority of the alternatives that were success- made loosely around the limb to avoid skin damage. The user
ful despite the combat scenario, the SWAT-T malfunctioned then continues to stretch and wrap the tourniquet around the
on two occasions by completely tearing into two pieces, and injured limb, and when done wrapping, the distal end of the
those that remained intact failed to both reach and maintain strap is tied to the 30cm tail, which was left outside the wrap-
vessel occlusion, requiring multiple adjustments after initial ping at the beginning (Figure 7). 19,44 Glick et al. compared the
application. Therefore, the SWAT-T lacks consistency both IST to the CAT in producing occlusive pressures. Male soldiers
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in controlled evaluations and simulations. with prior tourniquet training were assessed in their ability to
apply each type of tourniquet to a HapMed tourniquet trainer
FIGURE 6 The SWAT-T is an elastic-type tourniquet that is stretched in a low-stress environment. Even though the IST was more
as it is wrapped around the limb (obtained with permission from effective than the CAT in producing effective occlusion pres-
https://www.swat-t.com/).
sure (73% versus 91%, P = .007), the majority of participants
preferred the CAT for its simplicity. Montgomery et al. rated
44
it at 33.90 due to this user dissatisfaction and due to the sparse
literature made no recommendation for CoTCCC approval. 11

While the SWAT-T and IST are wrap-style tourniquets that
rely on self-tucking for their locking mechanism, the Rapid
Application Tourniquet System (RATS) uses a metal cleat for
locking the band (Figure 8). Placing the cleat on the injured
Despite these shortcomings and lower simplicity scoring, the
work by Ross et al. found the CAT to be no more intuitive FIGURE 7 The IST is an elastic-type tourniquet that is stretched as it
than the SWAT-T. Participants without prior instruction were is wrapped around the limb (https://israelifirstaid.com/6-5-feet-2-m
timed to the point where they believed they had applied their -2-5-inches-6-5-cm-emergency-silicone-tourniquet/).
device correctly, at which point it was assessed for correct
position, placement technique, and adequate tightness. The
overall success rate for correct tourniquet placement was
16.9%, with no tourniquet being more correctly placed than
another. Additionally, the wider coverage of the SWAT-T al-
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lows it to apply less pressure than the CAT to achieve vessel
occlusion. Studies conducted by Wall et al. found that while
both SWAT-T and CAT applications could cause pressures in
excess of 300mmHg, the CAT application pressure could be in
excess of 500mmHg. Furthermore, they also tested for inten-
tional occlusion failure by having participants cyclically tense
their extremity over the course of 1 minute and found that the
SWAT-T held the same pressure for longer with less occlusion
failure than the CAT. These findings were also seen in Wall
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et al.’s later study comparing it with the SOFTT-W and CAT,
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