Page 95 - JSOM Summer 2020

TABLE 2 Power Analysis Variables and Resulting Sample Sizes many C-A-T7 occlusion and completion pressures were actu-
Needed ally higher than measured. Some strengths were placements on
Standard human thighs; combination of controlled force applications
Deviation Estimated (Phase 1 thighs and models and Phase 2 models) and human
(mmHg) for Power Desired applier variability (Phase 2 and 3); investigation of possible
a Tourniquet Minimum to Rule In
Applier for Detectable or Out a effects on secured, occlusion, and completion pressures; and
Secured Pressure Pressure Statistically use of several different tourniquet designs.
and for a Difference Significant Estimated
Recipient Thigh Created by Difference with Number
for Occlusion Clothing State Two-Tailed of Subjects Conclusions
Pressure* (mmHg) p = .05 Required
Secured Pressure To avoid missing proximal injuries, guidelines for emergency-use
limb tourniquet applications in conditions other than Care Un-
32.8 10 0.80 193 der Fire should still recommend placement on bare skin rather
3
0.65 145 than over clothing. However, applications over clothing with
0.50 121 fabric pliability and coefficients of friction similar to scrubs
15 0.80 69 and Army uniform pants are unlikely to result in or need pres-
0.65 52 sures that are significantly different from applications on skin.
0.50 40 Surface to tourniquet interactions affect the ease of strap slid-
20 0.80 37 ing, so concern should still exist as to whether applications
0.65 28 over clothing are dislodged in a distal direction more easily
0.50 21 than applications on skin.
25 0.80 24 Acknowledgments
0.65 18 We thank the undergraduates of the Drake University Trauma
0.50 14 Research Team for all their help carrying out the experiments.
Occlusion Pressure
28.1 10 0.80 170 Disclosures
0.65 137 None of the authors have any financial relationships relevant
0.50 104 to this article to disclose, and there was no outside funding.
15 0.80 59
0.65 45 Author Contributions
PW and CB developed the concept and contributed to all as-
0.50 34 pects of the project. EH and HS contributed to design; the
20 0.80 32 acquisition, analysis, and interpretation of data; and the draft-
0.65 24 ing and revising of the article. CHR contributed to design,
0.50 18 the analysis and interpretation of data, and the drafting and
25 0.80 21 revising of the article. All authors had final approval of the
0.65 16 manuscript.
0.50 12
*Secured pressure standard deviations are an average for the C-A-T7, References
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