Page 122 - JSOM Summer 2020

FIGURE 8 The RATS is a unique elastic-type tourniquet that utilizes FIGURE 9 Ratchet-type tourniquets feature a lever on the tightening
a metal cleat to loop the free end onto after sequentially wrapping section that can be cinched after the unit is placed around the injured
the band around the limb instead of tucking in on itself (obtained limb (obtained with permission from https://www.revmedx.com/)
with permission from https://ratsmedical.com/).

The JOEFT assessed the RMT along with the SWAT-T, CAT,
SOFTT-W, and MAT, and found it to be just as effective in
in both application time and vessel occlusion in phases I and
II. 33,34 However, in phase III, it was directly compared against
the CAT and TMT, where it was as fast as the CAT in upper
extremity application but slower than CAT for the lower ex-
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limb, the user makes one wrap around the injured limb with tremity. It also was found to have similar failure due to user
the free end and feeds it through the loop that forms between error, which was echoed in the previous study by Ross et al.
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the metal cleat and the rope. The rope is then pulled in the that showed the RMT to be no more intuitive than the CAT.
opposite direction than it was originally wrapped in to tighten Furthermore, the two are also similar in losing occlusive pres-
it down and continued to be wrapped until tight. Once the sure over time. Rometti et al.’s study assessed the RMT as well,
majority of the rope has been used, the user locks it into the and found it dropped by 62mmHg, similar to the 68mmHg
metal cleat to secure the tourniquet in place. While studies seen with the CAT. However, the RMT had a more gradual
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are limited, the aforementioned study by Gibson et al. found loss in occlusion pressure, making the same drop over 6 min-
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that it did not perform as well as CAT in terms of time to utes as opposed to the 5 minutes seen with the CAT. The
hemorrhage control and fluid loss, making it less favorable ability of the RMT to hold pressure longer was also seen by
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than either the SWAT-T or IST. Given the limited literature, Wall et al., where only 1% of the applied RMTs lost occlusion
Montgomery et al. rated it at 34.00, and like the IST did not pressure 1 minute following application, compared with the
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recommend CoTCCC approval. Therefore, the layperson 28% seen with the CAT. Although promising, these results
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should be educated about the need for more evidence support- are only applicable to the Tactical RMT and Mass Casualty
ing its function. RMT, and are not all RMT models, as this group’s next study
compared the pediatric RMT to the CAT and found it had
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Furthermore, it should be noted that application of all three more failures after 2 minutes of application. The layperson
of these tourniquets requires increased manipulation of the should therefore be educated that overall these tourniquets are
injured limb compared with windlass-type models. While elas- a suitable alternative to the CAT but that smaller models have
tic-type tourniquets have existed for several decades, they have not been reliable in the literature.
not been as well studied as other tourniquet devices. The ma-
nipulation needed to sequentially wrap multiple constrictive Pneumatic-type Tourniquets
loops may cause increased pain and injury to the soft tissue Pneumatic tourniquets work by using inflatable bladders
of the limb, especially if the patient has a long-bone fracture. to increase the compression on the limb, with the two main
Although neither lab-based nor simulation-based research models available on the market, the Emergency and Military
has been conducted to investigate this question, the layperson Tourniquet (EMT) and Tactical Pneumatic Tourniquet (TPT).
should be aware of this potential consequence. To apply either, the user wraps the free end without the in-
flatable bladder around the injured limb, feeding through the
Ratchet-type Tourniquets clamp on the opposite end of the bladder (Figure 10). The
Ratchet-type tourniquets operate similarly to the windlass- user then pulls it through until tight against the limb, and then
type, but instead of having mechanical advantage provided by squeezes the clamp to secure the strap, pumping the inflation
a windlass, a ratchet on a track is used, as in the RMT. After bulb until the bleeding stops. 23,24 Both have been compared
the tourniquet is wrapped around the injured limb, the user with CoTCCC-approved windlass-type tourniquets in regard
feeds the loose end through the first and second metal rectan- to occlusion efficacy and were found to be just as successful;
gular loops on the opposite end, and then feeds it back on it- Taylor et al. actually found the EMT was found to be superior
self through only the first loop to tighten the tourniquet. Once to the CAT. 6,33,34,47–49 Despite their success, their low incidence
fastened, the user continues to tighten the tourniquet by lift- of reported prehospital use and high individual cost caused
ing the black lever on the ratchet until it cannot be tightened Montgomery et al. to score them at 38.00 and 34.62, respec-
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any further. This tourniquet is similar in function to the TX2 tively. However, as neither had no reported complications or
and TX3 tourniquets, and all three were collectively graded safety concerns, the authors noted that these models were
at 41.83 by Montgomery et al., receiving CoTCCC approval never intended for the prehospital environment but instead
(Figure 9). 11 for definitive hemorrhage control after the patient had been

120 | JSOM Volume 20, Edition 2 / Summer 2020