Page 47 - Journal of Special Operations Medicine - Summer 2016

Figure 2 Thigh and arm pressure changes following arterial occlusion losses. The pressure information from
Completion for each tourniquet application. the tourniquet applications that lost arterial occlusion is
shown with red symbols in Figures 1 and 2.

Arterial occlusion losses happened predominantly with
thigh applications: eight of 48 thigh applications lost oc-
clusion and only one of 48 arm applications lost occlusion
(thigh versus arm: p = .0305). Arterial occlusion losses
were most common with the Paired tourniquet applica-
tions: two of 16 Single thigh applications, six of 16 Paired
thigh applications, and one of 16 Paired arm applications
(thigh: p = .0150 for Single versus Wide versus Paired).

For the tourniquet applications that lost occlusion, the
pressure gains from Occlusion to Completion were
generally within the ranges present in the tourniquet
A applications that maintained occlusion. Additionally,
the pressure decreases from Completion to the time of
Occlusion loss were generally within the ranges of the
pressure decreases from Completion to 120-Seconds in
the tourniquet applications that maintained occlusion.
In other words, applications that would lose occlusion
could not be predicted by either smaller gains in pres-
sure from Occlusion to Completion or larger decreases
in pressure following Completion.

Tooth Skipping
A failure of the pawl to properly engage and pull the
ladder (tooth skipping) can occur with RMTs. Tooth
5
skipping did not occur in any tourniquet application in
this study.
B
Discomfort
The discomfort ratings are shown in Table 3. Most ap-
Each red symbol indicates data from an application that lost arte-
rial occlusion. Open diamonds, 3.8cm-wide Single Tactical Ratcheting plications received discomfort ratings of None or Little.
Medical Tourniquets (RMTs); center dot diamonds, 5.1cm-wide Wide
RMTs; black-filled left half diamonds, 3.8cm-wide Proximal Tactical
RMT of a Pair; gray-filled right half diamonds, 3.8cm-wide Distal Tac- Discussion
tical RMT of a Pair. (A) Tourniquet pressures decreased significantly
during the first 60 seconds. Among thigh and arm pressure decreases, Surprisingly, the measured Occlusion Pressures were not
post hoc comparisons indicated statistically significant differences lower under the 5.1cm-wide Wide RMT than under the
(p < .05) for the Single and Wide versus the Proximal and the Distal.
(B) Tourniquet pressures decreased more slowly during the second 60
seconds. Among 120-Second thigh and arm pressure decreases, post Table 3 Discomfort Ratings Associated with Tourniquet
hoc comparisons indicated p < .05 for the Single and Wide versus the Applications
Proximal and the Distal.
Tourniquet None Little Moderate Severe
than in the second 60 seconds (compare Figure 2A to Thigh
Figure 2B, p < .01 for each tourniquet on each limb).
For both the 60-Second and the 120-Second Pressures, Single, n = 16 1 12 2 1
the declines were not statistically significantly different Wide, n = 16 0 13 3 0
for the Single versus the Wide or for the Proximal ver- Paired, n = 16 2 13 1 0
sus the Distal, but the Paired pressure decreases were Arm
less than either the Single or the Wide pressure decreases
(thigh: p < .05, arm: p < .05). Single, n = 16 2 13 1 0
Wide, n = 16 4 12 0 0
Arterial Occlusion and Tourniquet Pressure Over Time Paired, n = 16 6 10 0 0
Every tourniquet application achieved arterial occlu- Thigh applications had greater discomfort ratings than arm applica-
sion. Along with pressure decreases over time, came tions (p < .0067).

Single, Wider, and Paired Tourniquet Pressures 33