Page 40 - Journal of Special Operations Medicine - Winter 2015

Different Width and Tightening System
Emergency Tourniquets on Distal Limb Segments

Piper L. Wall, DVM, PhD; Sheryl M. Sahr, MD; Charisse M. Buising, PhD

ABSTRACT

Background: Tourniquets are used on distal limb seg- Introduction
ments. We examined calf and forearm use of four thigh- Effective emergency tourniquets stop arterial blood flow
effective, commercial tourniquets with different widths and out of the systemic circulation and have lifesaving
1,2
tightening systems: 3.8cm windlass Combat Application roles in emergency care. The pressures required for
2–5
Tourniquet (CAT, combattourrniquet.com) and Special effectiveness have a relationship with the circumference
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Operations Forces Tactical Tourniquet-Wide (SOFTT- of the underlying limb and the width over which the
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W, www.tacmedsolutions.com), 3.8cm ratchet Ratcheting pressure is applied. In general, smaller circumference
6–8
Medical Tourniquet -Pediatric (RMT-P, www.ratcheting- locations and wider designs are expected to be associ-
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buckles.com), and 10.4cm elastic Stretch-Wrap-And-Tuck ated with lower tourniquet-applied pressures at arterial
Tourniquet (SWATT, www.swattourniquet.com). Meth- occlusion than would be the case for larger circumfer-
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ods: From Doppler-indicated occlusion, windlass comple- ence locations or narrower designs. Additionally, be-
6
tion was the next securing opportunity; ratchet completion cause higher pressures are associated with increased
was one additional tooth advance; elastic completion was morbidity, 9,10 emergency tourniquets that stop arterial
end tucked under a wrap. Results: All applications on the blood flow at lower pressures are considered desirable. 1
16 recipients achieved occlusion. Circumferences were
calf 38.1 ± 2.5cm and forearm 25.1 ± 3.0cm (p < .0001, The thigh is generally the largest-circumference limb seg-
t-test, mean ± SD). Pressures at Occlusion, Completion, ment and is expected to require the highest tourniquet
and 120-seconds after Completion differed within each pressures to reach and maintain arterial occlusion. The
design (p < .05, one-way ANOVA; calf: CAT 382 ± 100, US military, therefore, has considered the thigh the key
510 ± 108, 424 ± 92mmHg; SOFTT-W 381 ± 81, 457 ± limb segment when evaluating the potential effectiveness
103, 407 ± 88mmHg; RMT-P 295 ± 35, 350 ± 38, 301 ± of tourniquet designs. The thigh, however, is not the
1
30mmHg; SWATT 212 ± 46, 294 ± 59, 287 ± 57mmHg; only limb segment on which tourniquets are used. 2,5,11
forearm: CAT 301 ± 100, 352 ± 112, 310 ± 98mmHg;
SOFTT-W 321 ± 70, 397 ± 102, 346 ± 91mmHg; RMT-P The purpose of this study was to examine the distal limb
237 ± 48, 284 ± 60, 256 ± 51mmHg; SWATT 181 ± 34, segment use of four thigh-effective, commercial, emer-
308 ± 70, 302 ± 70mmHg). Comparing designs, pressures gency tourniquet designs with different widths and tight-
at each event differed (p < .05, one-way ANOVA), and the ening systems. The hypotheses were as follows: (1) all of
elastic design had the least pressure decrease over time (p < the tourniquets could occlude calf and forearm arterial
.05, one-way ANOVA). Occlusion losses differed among blood flow; (2) tourniquet width would be associated
designs on the calf (p < .05, χ ; calf: CAT 1, SOFTT-W with arterial occlusion pressures at each limb location in-
2
5, RMT-P 1, SWATT 0; forearm: CAT 0, SOFTT-W 1, dependent of tourniquet tightening systems; and (3) the
RMT-P 2, SWATT 0). Conclusions: All four designs can change in pressure from arterial occlusion to tourniquet
be effective on distal limb segments, the SWATT doing so application completion would vary by tightening system.
with the lowest pressures and least pressure losses over
time. The pressure change from Occlusion to Completion
varies by tourniquet tightening system and can involve a Methods
pressure decrease with the windlass tightening systems. The Drake University institutional review board ap-
Pressure losses occur in as little as 120 seconds following proved this prospective study. The Ratcheting Medical
Completion and so can loss of Occlusion. This is espe- Tourniquet -Pediatric (RMT-P; m2 Inc., www.ratcheting
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cially true for nonelastic strap tourniquet designs.
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buckles.com), the Combat Application Tourniquet (CAT;
Composite Resources, Inc., combattourniquet.com), and
Keywords: tourniquet; hemorrhage control; first aid; emer­ the Stretch-Wrap-And-Tuck Tourniquet (SWATT; TEMS
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gency treatment Solutions LLC, www.swattourniquet.com) were donated.
The SOF Tactical Tourniquet-Wide (SOFTT-W; Tactical
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