Page 80 - JSOM Fall 2018

also shows that the differences in tolerance between the two stress to simulate the physiological conditions of a Soldier in
tourniquets did not reach statistical significance. a fire fight.
Although a previous study demonstrated that the TMT can Conclusion
be tolerated when applied by another person, self­application
8
appears less well tolerated in the present study. Based on the The TMT is effective at occluding the popliteal artery when
current study, there is no evidence to suggest that the TMT is self­applied at mid thigh in healthy military volunteers. There
better during self­application than the C­A­T, which remains was no statistically significant difference between the C­A­T
an appropriate option for the self­arrest of catastrophic low­ and the TMT in terms of self­application time, pain, or over­
er­limb bleeding. all tolerance. There is no evidence to suggest that the TMT
should be used in preference to the C­A­T.
The TMT was not tolerated by 29% of volunteers. The sole
reason cited was pain, specifically pain from the skin being Disclosure
pinched underneath the tourniquet. This reason was the same Fenton Pharmaceuticals supplied the tourniquets with a mate­
for both tourniquets, although it was threefold more common rial transfer agreement for research. No funding was received.
in the TMT than the C­A­T (six versus two volunteers). Au­
thor application suggested that the rear surface of the TMT Author Contributions
in contact with the skin caused the painful stimulus. This was AB, MB, and PJP conceived the original concept and designed
felt to be due to shear forces rather than pure compression. the study. AB recruited participants. MB, ES, and RB per­
Future generations of the TMT may benefit from redesign of formed data collection, which was overseen by AB and PJP.
the interface between the device and the skin. AB wrote the first draft of the manuscript, and all authors
reviewed and edited the final manuscript.
All the study participants had self­applied the C­A­T before
during training, and some had applied the C­A­T to other References
wounded Soldiers, but none had used the TMT before. There­ 1. Kragh JF, Walters TJ, Baer DG, et al. Practical use of emergency
fore, participants could be described as familiar with the tourniquets to stop bleeding in major limb trauma. J Trauma.
C­A­T but unfamiliar with the TMT. Although of similar de­ 2008;64(2):38–50.
sign, unfamiliarity may have slowed TMT use in the current 2. Taylor DM, Vater GM, Parker PJ. An evaluation of two tourniquet
systems for the control of prehospital lower limb hemorrhage. J
study, which could be improved once familiarity is attained. Trauma. 2011;71(3):591–595.
3. Army B. Chapter 3: Catastrophic haemorrhage, in: Battlefield
Another limitation is that on the battlefield, when faced with Advanced Trauma Life Support Manual: Available from: https://
an actively bleeding limb, the incentive to fully tighten a tour­ i­site.mod.uk/course/view. 26 February 2016.
niquet to avoid exsanguination is greater. It could be likely 4. US Department of Defense. Tactical Combat Casualty Care 3 June
that the pain of injury would mask the pain of a self­applied 2015 Basic Management Plan for Tactical Field Care. http://www
.naemt.org/docs/default­source/education­documents/tccc/10
tourniquet, and therefore tests in healthy volunteers of this ­9­15­updates/tccc­guidelines­for­medical­personnel­150603
kind are less relevant. Equally, one can imagine a situation .docx?sfvrsn=2.
where a casualty is overwhelmed by injury, and self­applica­ 5. Kragh JF, Walters TJ, Baer DG, et al. Practical use of emergency
tion, therefore, is impossible. Thus, as a test of tourniquet util­ tourniquets to stop bleeding in major limb trauma. J Trauma.
ity, measures of self­application at the mid thigh may be of 2008;64(2):S38–S50.
limited generalizability; however, the methodology used in this 6. Kragh JF Jr, Moore VK 3rd, Aden JK 3rd, et al. Short report
paper represents an acceptable balance between practicality comparing Generation 6 versus prototype Generation 7 Combat
Application Tourniquet(R) in a manikin hemorrhage model. J
and translatability. Spec Oper Med. 2016;16(1):14–17.
7. Gibson R, Housler GJ, Rush SC, et al. Preliminary comparison
It is known that arterial occlusion pressures are greater in of new and established tactical tourniquets in a manikin hemor­
thighs of larger circumference. 9,10 Knowing this association rhage model. J Spec Oper Med. 2016;16(1):29–35.
may further the understanding of tourniquet users; however, 8. Beaven A, Briard R, Ballard M, et al. Two new effective tour­
a battlefield tourniquet must be effective across a wide range niquets for potential use in the military environment: a Serving
Soldier Study. Mil Med. 2017;182(7):e1929–e1932.
of body sizes. We chose not to measure thigh circumference in 9. Loenneke JP, Allen KM, Mouser JG, et al. Blood flow restriction
our volunteers, because we felt the tourniquets should work in the upper and lower limbs is predicted by limb circumference
regardless of thigh shape. and systolic blood pressure. European journal of applied physiol­
ogy 2015;115(2):397–405.
The simulated hemorrhage model is not equivalent to expe­ 10. Kragh JF Jr, O’Neill ML, Walters TJ, et al. The military emer­
riencing real catastrophic hemorrhage; however, it is a meth­ gency tourniquet program’s lessons learned with devices and de­
signs. Mil Med. 2011;176(10):1144–1152.
odology that has been used in previous studies of this kind.
Additional research could be conducted under conditions of

78 | JSOM Volume 18, Edition 3 / Fall 2018