Page 61 - JSOM Fall 2020

FIGURE 6 Occlusion pressures versus circumference correlations.

(A) (B)

On all panels, data points represent means of the triplicates; the y-axis has occlusion pressures (mmHg), and the x-axis has limb circumferences
(cm). (A) Combined thigh occlusion pressures versus circumference, r = 0.24 with P < .0001. (B) Arm occlusion pressures versus circumference,
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r = 0.027 with P = .38.
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TABLE 2 Thigh Occlusion Pressures With Different Tourniquets
Occlusion Pressure (mmHg)
Tourniquet Minimum 5th Percentile 25th Percentile Median 75th Percentile 95th Percentile Maximum
OMNA Marine Tourniquet 275 289 337 348 380 451 521
(n = 60)
Tactical RMT (n = 15) 264 264 302 315 352 383 383
SOFTT-W 3 (n = 15) 284 284 325 350 387 447 447
C-A-T7 (n = 15)* 344 344 389 403 483 624 624
Completion Pressure (mmHg)
OMNA Marine Tourniquet 320 349 392 414 456 523 588
(n = 60)
Tactical RMT (n = 14) 319 319 350 365 385 448 448
SOFTT-W 3 (n = 12) 241 241 307 371 449 599 599
C-A-T7 (n = 10)* 447 447 503 558 694 851 851
All applications were mid-thigh on bare skin with subjects sitting in a chair, the thigh parallel to the floor with the lower leg at a 90° angle, and
instruction to maintain the thigh in a relaxed state. Values are from the means of triplicates.
Tactical RMT, Tactical Ratcheting Medical Tourniquet; SOFTT-W 3, Generation 3 SOF Tactical Tourniquet–Wide; C-A-T7, Generation 7
®
Combat Application Tourniquet
*C-A-T7 pressures are higher than each other tourniquet (P < .0001).
Sources: Tactical RMT, SOFTT-W3, and C-A-T7 data from reference 16 is used with permission from Journal of Special Operations Medicine;
Clothing effects on limb tourniquet application. Authors; Wall P, Buising C, Hingtgen E, Smith H, Renner CH; J. Spec Oper Med. 2020 Summer;
20(2):83–94.

needing to hold the tourniquet against sliding also allows the As noted, there were statistically significant but not impressive
redirect buckle to behave as a moving pulley for a mechani- correlations between secured pressures and clicks to occlusion
cal advantage benefit over a completely stationary redirect (a and very weak correlations between occlusion pressures and
redirect that is prevented from moving in concert with tissue clicks. Essentially, the number of clicks needed to reach occlu-
compression). The slightly tacky section is not of sufficient sion can be used as an indicator of the quality of the secured
length to negatively influence pulling the strap through the re- pressure achieved during an application, but a set number of
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direct buckle. We found this design feature (a short distance clicks absolutely should not be suggested as likely to indicate
of slight tackiness) highly advantageous in our laboratory set- an occlusive application.
ting that, because of the use of the pressure measuring sys-
tem, included initial positioning of the tourniquet on the limb Within a given subject, the median occlusion pressure coeffi-
by a researcher. How or whether the design feature would cient of variation was 7.7% (thigh) and 7.0% (arm). This is an
translate to an application advantage in other settings is of indicator of the combination of the consistency of the pressure
interest. at which occlusion occurred in each subject, the resolution of

OMNA Marine Tourniquet Self-Application | 59