Page 41 - Journal of Special Operations Medicine - Fall 2016

27cm surface that faces away from the limb; the 27cm the FDA as a pneumatic tourniquet. The device used in
surface has a bulb and tube. The Velcro type is Omni- this experiment was TPT2 model (parts number) 60062
tape, a version with hooks and loops together and not and had a stamped imprint of a date on the fabric of the
separated on opposing surfaces. outer cover. The model is a single-use device.

At the junction of the Y, the bladder and its extension are The TPT3 shares similar traits with the TPT2, as dis-
sewn to the nonpneumatic outer cover that is to overlay cussed, except that TPT3 is 3 inches wide and, in the
the inner cover. The black outer cover is 94cm long and models tested in this study, the TPT3 had a zip-tie that
is routed through two slits of a slider (a buckle with reinforced the tube connection to the pump, whereas the
three parallel bars and two slits between the bars) that is TPT2 did not have a zip-tie. The TPT3 weighs about
mobile along the length of the outer cover. The cylindri- 193g and costs about $69. The device used was TPT3
cal bar of the slider (the other two bars are squared at model number 60063 and had a stamped imprint of a
the edges) snaps into a receiver (hook) of matched size; date: 061515. The model is a single-use device.
the black hook is also connected at the junction of the
Y. The slider and receiver are made of a plastic-like com- This study intended that each device tested was normal
posite material. The running end of the outer cover is in structure and function. We also were interested in
pulled to remove remaining slack. Thus, the outer cover determining if the devices could withstand mechanical
adds circumferential tension atop the inner cover. After loading multiple times successively; if such use led to no
snapped and pulled through the slider, the running end wear and tear in the laboratory experiment, then fur-
of the outer cover has its Velcro surface folded over the ther development may be useful to change the current
bar to face the receiver end so that the outer cover can regulatory clearance from a single-use limitation to al-
be secured to itself; this self-adhering outer cover acts low multiple uses. Devices were examined throughout
like the self-adhering band of the standard issue wind- the experiment for structural and functional integrity to
lass-and-band tourniquet used in the US military forces identify potential wear or breakage, which would lead
in 2015. The tube and hand bulb are also overlaid by to device replacement.
the outer cover, but the tube length is enough for the
bulb to be outside and not under the outer cover. The The tourniquets were used by one person, a clinician-
pump is small and is flat on one side to lessen its storage scientist and tourniquet expert who has tourniquet
size. The release valve and its threads are metal. experience in trauma care; such experience included
clinical use of the EMT but not with the application of
The TPT2 was designed by two professional medical de- the two TPT models. The user self-trained previously
velopers who were US Army enlisted medics. The TPT2 with use of all three models. The TPT video was also
was delivered rolled up in a clear plastic wrapper with a viewed for additional instruction of use. Such training
paper copy of its 1-page IFU. As stowed, the TPT2 roll included reading the instructions for use, handling the
has the inner cover rolled exteriorly; the outer cover is device, and two practice uses for each tourniquet model
rolled within. The outer cover has a small, clear-plastic on the manikin before testing began. Additional prior
pin (in a 1-inch-long U-shaped clip) that holds the outer experience with the three tourniquet models included a
cover rolled so that when the TPT2 is opened initially, prior laboratory experiment with 10 uses of each model;
it unfurls only the inner cover while the outer cover the devices were not the same but similar to those used
stays rolled. After the inner cover is placed around the in the present study. There were 30 test iterations per
limb and is secured, the pin is grasped and removed so tourniquet model in the experiment; hence, the user
the outer cover unfurls by gravity. On the outer cover, made 90 iterations altogether for the experiment.
a date of manufacture is printed, and instructions and
corporate information are printed indelibly. A white la- The tourniquets were tested on a laboratory manikin
bel with “Time” printed on it is at the running end of designed to train users by providing feedback on user
the outer cover for the user to record the time of initial performance. In this experiment, the user had self-
application. The IFU only specify high and tight use on trained in use of the manikin and had worked with it of-
™
the most proximal portion of the limb; they do not men- ten for several years. The manikin was a HapMed Leg
tion any other place on the limb to put the device. Nor Tourniquet Trainer (leg number 000F; CHI Systems,
do they indicate if the TPT2 is designed for one-handed http://www.chisystems.com/); a simulated right-thigh
use: the drawings show a casualty having another per- with an above-knee amputation injury was the testing
son applying it in a two-handed fashion. The IFU state apparatus. 15–17 The medial hip had an embedded com-
that the TPT is a single-use device. puter and a smartphone-like touchpad. Software (ver-
sion 1.9; CHI Systems) integral to the manikin allowed
The TPT2 is made in the United States, weighs about it to stand alone and be operated by user input through
144g, and costs about $69. The TPT2 is registered with finger touch on the pad.

Evaluation of Pneumatic-Tourniquet Models 23