Page 57 - JSOM Fall 2020

FIGURE 2 Pressures and coefficients of variation.

(A) (B)

(C) (D)

On all panels, data points represent per subject data in triplicate and share the same symbols. On panels A–C, the y-axis has pressures (mmHg),
and the x-axis has each subject’s data grouped by single arm pull (kg). On panel D, the y-axis has coefficients of variation for pressures, and the
x-axis has the type of application. (A) Secured pressures. Combined thigh versus arm, P < .0001. (B) Occlusion pressures. Combined thigh versus
arm, P < .0001. (C) Completion pressures. (D) Coefficients of variation with bars showing medians and interquartile ranges.
During the research applications, 90° redirect buckle reorien- The easiest method of releasing each tourniquet application
tation occurred twice: once during a third application (thigh was via disengaging the hook-and-loop to hook-and-loop
up) by an applier who pulled 18.14kg and once during a fifth strap surfaces from each other. Resetting the ratcheting buckle
application (thigh down) by an applier who pulled 31.75kg. to the start point on the ladder took some effort. The space
In both instances, the redirect buckle was repositioned in the between the black portion of the ratcheting buckle and red,
sleeve before the next application, and the tourniquet was used “lift to open,” release lever of the ratcheting buckle (Figure
without incidence for the remaining applications. Additionally, 1) is small enough that we could not slip the end of a Sharpie
the redirect buckle was slightly repositioned in the sleeve after a marker into the space to hold the release position while reset-
third application (thigh up) by an applier who pulled 18.14kg. ting the ratcheting buckle. This restricted releasing to requir-
The remaining uses were without redirect buckle reorientation. ing holding the releasing lever up with a finger; the problems
with this were that larger fingers would not fit, and for fingers
During seven applications (three thigh down, three thigh up, that fit, the process was physically uncomfortable (only the
and one arm), some hook-and-loop to hook-and-loop strap fingertip fits, and releasing and resetting the ratcheting buckle
interaction occurred during the strap pulling to the secured requires significant pressure application).
pressure. This is an expected occasional issue with any tour-
niquet using a hook-and-loop covered strap. Six of the seven Discussion
involved applications had somewhat lower secured pressures
than the other same set pulls (thigh down, thigh up, arm) of The key findings are the OMNA Marine Tourniquet is effec-
the same applier. tive (540 of 540 applications reached occlusion and comple-
tion) and can be self-applied effectively including one-handed
Most appliers found advancing the ratcheting buckle during arm application (180 of 180 one-handed applications). Addition-
applications to be a bit awkward. All appliers were successful ally, adult appliers can regularly achieve secured pressures
at advancing the ratcheting buckle despite any awkwardness. >150mmHg (376 of 453 applications, 89 of 93 of which were

OMNA Marine Tourniquet Self-Application | 55