Page 69 - Journal of Special Operations Medicine - Fall 2014

Figure 2 Time to effectiveness by model of junctional The second major finding was that the effectiveness rate
tourniquet. Average time to effectiveness in seconds varied for the four models tested varied from 11% to 100%.
by model of junctional tourniquet. The SJT and CRoC had The most effective junctional tourniquets tested were
the fastest times to effectiveness; their difference was not the SJT and CRoC. The next most effective model was
statistically significant. The AAJT had too few effective tests the JETT. A low effectiveness rate was associated with
to analyze meaningfully. The JETT had the slowest times to
effectiveness. Each column represents the mean and each bar severe pain with the AAJT to such a degree that the
notes the standard deviation of the sample. simulated casualties stopped the test iteration in the re-
maining 89% of uses—all of which were therefore inef-
fective. Because the SJT and CRoC were ranked best
and were most effective, the first and second main find-
ings were concordant.

A minor finding of the testing was that no safety issues
arose because no adverse events occurred; the four de-
vices were equally safe. Longer-term studies would be
needed to verify the safety of these models. Informally,
medics said that comfort varied by model; they reported
the most comfortable junctional tourniquet was the
CRoC. The most uncomfortable junctional tourniquet
was the AAJT. Pain felt may have affected preference;
Figure 3 Medic ranking of preference for junctional
tourniquet models. Preferences for CRoC versus SJT and the lowest ranked tourniquet exerted the most pain, and
AAJT versus JETT did not differ (p > .05). the highest ranked tourniquet exerted the least pain. Ad-
ditionally, while the CRoC had 94% effectiveness ver-
sus 100% for the SJT, medics ranked the CRoC over
the SJT by a difference that was not statistically signifi-
cant; the preference may been affected by the superior
CRoC comfort, which may be a crossover effect from
simulated casualty experience into user rankings. In a
previous study, the CRoC was also found to have the
least pain of the four junctional tourniquets; however,
because testers were also subjects, the experience as sub-
jects may have influenced their experience as testers (J.F.
Kragh Jr, unpublished observations).

The strength of the present testing is that it offers a di-
Discussion
rect comparison by military medics of the four currently
The first major finding of the present junctional tour- FDA-approved junctional tourniquets. This strength
niquet testing was that medics preferred the CRoC and fills a specific knowledge gap for junctional tourniquets
SJT and ranked them highest. Conversely, these medic on their differential performance in the hands of med-
users ranked the AAJT and the JETT as the worst. ics. Such new knowledge may aid decision-makers in

Table 2 Ranked Preferences of Junctional Tourniquet by Model
User Preference by Model Score by Model
Rank* Score CRoC AAJT JETT SJT CRoC AAJT JETT SJT
1 4 † 7 ‡ 0 0 2 28 § 0 0 8
2 3 1 2 1 5 3 6 3 15
3 2 1 3 4 1 2 6 8 2
4 1 0 4 4 1 0 4 4 1
Sum 9 9 9 9 33 16 15 26
Notes: *Rank 1 = best; Rank 4 = worst.
† Points assigned to the highest rank of 1.
‡ Number of users who gave this tourniquet a rank of 1 = best.
§ Score for each tourniquet (No. of users × score).

Junctional Tourniquets to Control Simulated Groin Hemorrhage 61