Page 36 - Journal of Special Operations Medicine - Winter 2015

Figure 2 Results of pressure varied by tourniquet group. In the present study improvised tourniquets were again
The commercial Combat Application Tourniquet (CAT) had shown to be inferior to a manufactured, commercially
the highest mean pressures and all such pressures were within available tourniquet, the CAT. However, the need to
safe and effective ranges. Both improvised tourniquet groups control hemorrhage can appear suddenly almost any-
had tests with low pressure values that were associated with where. Thus, the need to improvise hemorrhage control
ineffectiveness. The data range (maximum minus minimum)
by group varied almost fivefold from 46mmHg for the remains a concern, and use of improvised tourniquets,
commercial CAT to 229mmHg for the bandage. therefore, remains a gap in both knowledge and perfor-
mance. Complicating a decision to use an improvised
tourniquet are its difficulty in correct use, its painful
constriction, and its risk for causing complications. 15,35–37

One minor finding of the present study was that proxi-
mal thigh use of the improvised tourniquets did not
result in reliable hemorrhage control. On the contrary,
Swan et al., using human volunteers, found that three
types of improvised tourniquets (sphygmomanometer,
0.5- inch rubber tubing, cloth and windlass) were suc-
cessful in most subjects. These authors concluded
36
that all such tourniquets can be used successfully be-
low the knee or below the elbow. Differences in study
results between the present study and that of Swan
et al. are rooted in the different purposes and study
designs.
Figure 3 Results of blood loss varied by tourniquet group.
The commercial Combat Application Tourniquet performed
best; all results of blood loss in the commercial group were The second minor finding of the present study was that
less than the minimums of either other group. difficulties encountered with effectiveness of improvised
tourniquet use on manikins were similar to those re-
ported for humans after the Boston Marathon bomb-
ing. In that incident, 27 improvised tourniquets were
25
applied for which no mortality was associated. King et
al. concluded that limb exsanguination at the point of
25
injury during the Boston Marathon was either left un-
treated or treated with an improvised tourniquet. They
held that effective, prehospital procedures to control
limb hemorrhage should be taught to all civilian first
responders in the United States. Moreover, such pro-
cedures should be based on the military’s procedures
for extremity bleeding control. Our data and those
25
of King et al. provide evidence both for the difficulties
associated with effective use of improvised tourniquets
and for the need of a greater availability of commercial
tourniquets.

Discussion
The strength of the present testing of two improvised
The major finding of the present experiment was that tourniquet techniques and a common commercial tour-
the CAT performed best; two improvised tourniquet niquet is that comparisons could be made among the
models performed markedly worse than the commercial three groups to see if improvised techniques varied in
CAT. The CAT, a tourniquet specifically designed for performance from one another and if commercial tour-
first aid by nonmedical personnel, has been a standard- niquet performance was different than either improvised
issue US military tourniquet since 2005. The CAT has technique. The main finding of the present study adds to
been the subject of numerous studies, has had a great a small but growing body of medical literature that in-
deal of use clinically, and is frequently used to teach dicates improvised tourniquets do not work as well as
tourniquet procedures. On the contrary, although im- common commercial tourniquets. 25
provised tourniquets have been used in many forms for
centuries, they have not been empirically assessed, and Limitations of the present testing are rooted in the design
some authors discourage their use. 31–34 of the study. Ideal laboratory conditions do not mimic

24 Journal of Special Operations Medicine Volume 15, Edition 4/Winter 2015