Page 47 - Journal of Special Operations Medicine - Spring 2015

occur by hybrid maneuvers such as manual compres­ adjuncts should be considered. Study of human factors
sion during the tourniquet placement and application in out­of­hospital healthcare, such as learning curves by
before the tourniquet is made fully effective. It is un­ lifesaving intervention (eg, tourniquet use or airway in­
10
clear if this process occurred in the present study. Blood terventions), may help refine best care practices.
loss was continuous data, but hemorrhage control was
binary (ie, yes or no); in actuality, hemorrhage control In summary, whether emergency tourniquet had ex­
can be partial in that it can exist as incomplete stoppage posure to heat or not, damage rates were similar; all
of flow. In the way we used hemorrhage control in the measures of performance except one, blood loss, were
present study, partial hemorrhage control was reduced similar irrespective of exposure, but they were not wors­
to no hemorrhage control, meaning that control was not ened by heat.
attained completely. Hemorrhage control as a rate in
mL/s is calculable with the methods available and may Funding
offer opportunities for further study; for example, one
user, the physician assistant, in the present study had This project was funded with internal US Army Medical
rates ranging from 3mL/s to 19mL/s, a 6­fold difference, Research and Materiel Command funds and the Defense
while the other had rates ranging from 4mL/s to 9mL/s, Health Program (Proposal 201105: Operational system
a 2­fold difference. management and postmarket surveillance of hemor­
rhage control devices used in medical care of US Service­
The strength of the present testing is that it was a focused, persons in the current war). The study was performed
controlled experiment that provided a definitive answer at USAISR.
to the specific exposure addressed. By using a laboratory
study, investigators (both had formal tourniquet training Disclaimer
and also had field experiences in out­of­hospital care)
were able, with the aid of an experienced research team The opinions or assertions contained herein are the pri­
(including a biostatistician), to implement an experiment vate views of the authors and are not to be construed
that answered a question from the field. Operational as official or reflecting the views of the Department of
medicine is often based on hospital medicine, but the Defense or US Government. The authors are employees
context of operational medicine in the field often is sub­ of the US Government. This work was prepared as part
stantially different; environmental exposure of medical of their official duties and, as such, there is no copyright
devices is more of an issue in the field than in the hospital. to be transferred.

Limitations of the study include the order of testing, as Disclosures
learning of users with increasing test numbers (a mea­
sure of experience) was observed; this learning was The authors declare no conflicts of interest.
confounding in the assessment of other variables, but
the effect of learning was small enough not to affect the References
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Testing of Tourniquets Exposed to Prolonged Heat 37