Page 42 - Journal of Special Operations Medicine - Summer 2016

Pressures Under 3.8cm, 5.1cm,
and Side-by-Side 3.8cm-Wide Tourniquets

Piper L. Wall, DVM, PhD; Jacob Weasel, MD; Mary Rometti, BS; Sarah Birkholz, BA;
Yvonne Gildemaster, BS; Lisa Grulke, BA; Sheryl Sahr, MD; Charisse M. Buising, PhD

ABSTRACT

Background: Applications of wider tourniquet are ex- Keywords: tourniquet; hemorrhage; first aid; emergency
pected to occlude arterial flow at lower pressures. We treatment
examined pressures under 3.8cm-wide, 5.1cm-wide, and
side-by-side-3.8cm-wide nonelastic strap-based tourni-
quets. Methods: Ratcheting Medical Tourniquets (RMT) Introduction
were applied mid-thigh and mid-arm for 120 seconds with
Doppler-indicated occlusion. The RMTs were a Single Rapidly applied, effective, emergency use tourniquets
Tactical RMT (3.8cm-wide), a Wide RMT (5.1cm-wide), save lives by stopping arterial blood flow. Based on
1,2
and Paired Tactical RMTs (7.6cm-total width). Tighten- results with pneumatic tourniquets on limbs, wider ef-
3
ing completion was measured at one-tooth advance past fective limb tourniquet designs are expected to stop ar-
arterial occlusion, and paired applications involved alter- terial blood flow at lower tourniquet applied pressures.
nating tourniquet tightening. Results: All 96 applications Lower tourniquet pressures are expected to carry less
on the 16 recipients reached occlusion. Paired tourniquets risk of nerve injury and to be easier to achieve.
had the lowest occlusion pressures (p < .05). All pressures
are given as median mmHg, minimum-maximum mmHg. The most commonly used limb tourniquets in the US
Thigh application occlusion pressures were Single 256, military are composed of a mechanical advantage tight-
219–299; Wide 259, 203–287; Distal of Pair 222, 183– ening system and a nonelastic strap. Use recommen-
256; and Proximal of Pair 184, 160–236. Arm applica- dations for these tourniquets include adding a second
tion occlusion pressures were Single 230, 189–294; Wide tourniquet immediately adjacent to the first to reach ef-
212, 161–258; Distal of Pair 204, 193–254, and Proxi- fectiveness should the first tourniquet not be sufficient.
4
mal of Pair 168, 148–227. Pressure increases with the fi- Support for the effectiveness of increasing strap-based
nal tooth advance were greater for the 2 teeth/cm Wide tourniquet width by adding an adjacent tourniquet
than for the 2.5 teeth/cm Tacticals (p < .05). Thigh final comes from military limb tourniquet use data. 1,2
tooth advance pressure increases were Single 40, 33–49;
Wide 51, 37–65; Distal of Pair 13, 1–35; and Proximal of The purpose of this study was to examine pressures un-
Pair 15, 0–30. Arm final tooth advance pressure increases der different width, nonelastic strap-based tourniquets.
were Single 49, 41–71; Wide 63, 48–77; Distal of Pair 3, Ratcheting Medical Tourniquets (RMTs; m2 Inc., www
®
0–14; and Proximal of Pair 23, 2–35. Pressure decreases .ratchetingbuckles.com) were used because their self-
occurred under all tourniquets over 120 seconds. Thigh securing, ratchet-based tightening system allows finer
pressure decreases were Single 41, 32–75; Wide 43, 28– resolution pressure control at completion than can be
62; Distal of Pair 25, 16–37; and Proximal of Pair 22, achieved with current commercially available windlass
15–37. Arm pressure decreases were Single 28, 21–43; systems. The hypotheses were the occlusion and comple-
Wide 26, 16–36; Distal of Pair 16, 12–35; and Proximal tion pressures would be highest under the single 3.8cm-
of Pair 12, 5–24. Occlusion losses before 120 seconds oc- wide Tactical RMT, lower under the single 5.1cm-wide
curred predominantly on the thigh and with paired appli- Wide RMT, and lowest under the pair of 3.8cm-wide
cations (p < .05). Occlusion losses occurred in six Paired Tactical RMTs.
thigh applications, two Single thigh applications, and one
Paired arm application. Conclusions: Side-by-side tour- Methods
niquets achieve occlusion at lower pressures than single
tourniquets. Additionally, pressure decreases under tour- The Drake University Institutional Review Board ap-
niquets over time; so all tourniquet applications require proved this prospective study. The RMTs were requested
reassessments for continued effectiveness. from and donated by m2 Inc.

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