Page 45 - Journal of Special Operations Medicine - Summer 2016

the pull to Friction Pressure). Additionally, arm appli- of the Single and Wide tourniquets were not statistically
cations on the three women with the smallest circum- significantly different from each other and were higher
ference arms required movement of the Strap cuff 2cm than the Occlusion Pressures of each of the Paired tour-
closer to the ladder attachment to avoid pulling the in- niquets. On the arm, only the Proximal of the Pair had
flated bladder into the friction buckle. Strap pressures in statistically significantly lower Occlusion Pressures than
these applications are, therefore, not comparable to the the others.
other Strap pressures.
Completion Pressures
Ladder versus Strap Pressures At one-tooth advance past Occlusion, Completion Pres-
The amount of air-filled bladder constraint applied by sures were higher than Occlusion Pressures (Figure 1B).
different parts of tourniquets and by different anatomi- For each limb, the gain from Occlusion to Completion
cal structures affects the pressures measured under dif- was greatest for the Wide RMT, which has 2 teeth/cm
ferent parts of tourniquets. Comparing Ladder and
5,8
Strap pressures from Occlusion onward (Table 1), only Figure 1 Thigh and arm Occlusion and Completion
five tourniquets had any Ladder Pressures lower than Pressures for each tourniquet application.
Strap Pressures; each of the five was a Proximal of Pair
in an arm application. For a given limb location, the
greatest differences between Ladder and Strap Pressures
were present in the tourniquet applications with the
highest Occlusion Pressures (Occlusion Pressures shown
in Figure 1A). From Occlusion through 120- Seconds,
the pressure differences generally did not change by sta-
tistically significant amounts. With the pressure measur-
ing system used, Strap Pressures are more reasonable to
compare across different types of strap-based tourni-
quets; therefore, only Strap Pressures are shown in all
7
of the figures and in the remaining tables.

Nonequivalence of Proximal A
and Distal Paired Tactical RMTs

Placing a second tourniquet adjacent to the first allows
widening of the zone of compression. With the methods
used, the two tourniquets in a pair would not necessar-
ily have the same pressures. Occlusion Pressures (Fig-
ure 1A) under the proximal and distal Tactical RMTs in
the Paired configuration were not equivalent in thigh or
arm applications (p < .05).

On both limbs, the Distal of the Pair generally had the
higher pressure at Occlusion (median mmHg, minimum–
maximum mmHg: thigh distal 222, 183–256, thigh
proximal 184, 160–236; arm distal 204, 193–254, arm
proximal 168, 148–227). During thigh applications, the B
ladder tooth advance to reach Occlusion occurred on
the distal tourniquet seven times and on the proximal Each red symbol indicates data from an application that lost arte-
tourniquet nine times. During arm applications, the rial occlusion. Open diamonds, 3.8cm-wide Single Tactical Ratcheting
ladder tooth advance to reach Occlusion occurred on Medical Tourniquets (RMTs); center dot diamonds, 5.1cm-wide Wide
RMTs; black-filled left half diamonds, 3.8cm-wide Proximal Tactical
the distal tourniquet once; Occlusion was reached dur- RMT of a Pair; gray-filled right half diamonds, 3.8cm-wide Distal
ing the proximal tourniquet pull to Friction Pressure six Tactical RMT of a Pair. (A) Arterial Occlusion Pressures. Among thigh
times, and the ladder tooth advance to reach Occlusion Occlusion Pressures, post hoc comparisons indicated statistically sig-
nificant differences (p < .05) for the Single and Wide versus the Proxi-
occurred on the proximal tourniquet nine times. mal and the Distal and for the Proximal versus the Distal. Among
arm Occlusion Pressures, post hoc comparisons indicated p < .05 for
Occlusion Pressures the Single and Wide and Distal versus the Proximal. (B) Completion
Pressures. Among thigh and among arm Completion Pressures, post
The Paired tourniquets had the lowest Occlusion Pres- hoc comparisons indicated p < .05 for the Single and Wide versus the
sures (Figure 1A). On the thigh, the Occlusion Pressures Proximal and the Distal and for the Proximal versus the Distal.

Single, Wider, and Paired Tourniquet Pressures 31