Page 54 - Journal of Special Operations Medicine - Spring 2016

The mean age of the medics was 22 years (range, 20–24 were stowed in its storage pouch; this configuration was
years). Individual medics had an average of 24 months the way the model was delivered to purchasers. The
(range, 18–28 months) since completion of their initial recommended storage configuration was subsequently
Combat Medic training program, and their average refined by the maker in April 2014, but notification of
length of military service was 30 months (range, 26–36 this change had not been made by the time of testing. In
months). testing, tourniquets were applied in accordance with the
available instructions for use of each model. All models
Because of conflicts with the work schedules of the med- were applied directly to one side of the groin. The order
ics, they were divided to two groups. The first group had of testing of the four models of tourniquet was by their
nine medics and the second had five. Prior to testing, in- date of original FDA clearance for the inguinal indica-
dividual medics received junctional tourniquet training tion: CRoC, AAJT, JETT, and SJT.
with each model. The trainers were the four physicians
who later assessed effectiveness during testing. Test results included safety, effectiveness, time to effec-
tiveness, and user preference. Effectiveness was a yes/
Simulated casualties were represented by the medics no determination for each test and was expressed as the
themselves. In between testing, medics who had been overall percentage of success for each model; percentage
users acted as simulated casualties; this dual role pro- was calculated as the number of effective tests divided
vided the medics the experience upon which to assess by the total number of tests. Time to effectiveness for
the models more thoroughly than by just being a user. each test was from the start to the time of determination
Some of the testers acted first as simulated casualties and of effectiveness. After testing was otherwise complete,
later acted as testers; the rest of the medics acted first as users subjectively ranked their preference of tourniquet
testers before acting as testers. The tester-casualty roles performance. Users ranked their preference of models
changed between each test. There was no preset order used by answering the question “If you had to go to war
for individual medics starting as a casualty or tester. The today and you could only choose one, which tourniquet
combat uniform was worn by the simulated casualty, would you choose to bring?” The rank was a whole
but boots and socks were removed before testing to al- number ascribed by a user to a given device (1 = best
low assessment of distal pulse. There was a 5-minute to 4 = worst). The rank was also converted into a point
rest period between test iterations. Hence, all tests were score (score = 5 minus rank). The users’ scores by model
conducted on a given subject within a 2-hour period. were summed. For 14 users with 4 points allotted to the
best rank, the best possible score was 56; the worst pos-
The focus of interest was the medics’ experience in junc- sible score was 14.
tional tourniquet use in training and testing. The sur-
rogate for bleeding was the presence of a distal pulse The first method of analyzing ranks was to use the
detected by manual physical examination. Pulse absence rank number (1, 2, 3, or 4) by each user for all models
during junctional tourniquet use represented effective- assessed to generate points (rank 1 was weighed at 4
ness in hemorrhage control. An assessing physician of points, rank 2 had 3 points, rank 3 had 2 points, and
the instructor team checked the distal pulse at the ankle rank 4 had 1 point), so such user preference included all
at both the posterior tibialis artery and the dorsalis pe- ranks for each user. An average of points by model was
dis artery. The pulse was assessed for 30 seconds after made to represent each model’s overall ranking. The sec-
completion of application of the tourniquet. After as- ond method of analyzing user preference was to assess
sessment of effectiveness, the tourniquet was removed. only the highest-ranked model (most preferred) for each
user instead of analyzing all rankings (second, third, and
Safety was defined as an absence of adverse events (any least preferred); an average was calculated to represent
undesirable sign, symptom, or medical or psychologi- each model’s measure of being most preferred.
cal condition) during and after the application of the
junctional tourniquet. Uncomplicated pain that resolved Descriptive statistics were used to portray results. Statis-
promptly after device use was not considered an adverse tical testing included a mixed-model analysis of variance
event. Safety issues were determined during the testing (MANOVA) to see if any model was different from the
by the physician observing the application of the devices others, taking into account the user effect, which was a
in real-time. Subjects were assessed during testing and 2 nontreatment effect that confounded the treatments ef-
hours later to assess for adverse events. fect (models of junctional tourniquet). Effectiveness by
model of junctional tourniquet was compared in con-
Tourniquets were placed opened, ready for use, and tingency tables with a χ test using JMP version 10.0
2
near the user; the tourniquets were neither packaged (SAS Institute; https://www.sas.com) and MS Excel
(commercially wrapped) nor packed away in medic 2003 (Microsoft; https://www.microsoft.com). Pairwise
bags. The CRoC was disassembled into its parts, which comparisons of effectiveness by model were made with

38 Journal of Special Operations Medicine Volume 16, Edition 1/Spring 2016