Pressure Responses of Tourniquet Practice Models to Calibrated Force Applications

Tourniquet training sometimes involves models, and a certification process is expected to use something other than human limbs; therefore, investigating model- and limb-pressure responses to force application is important.

Pressure response to force was collected for a 3.8cm-wide nonelastic strap and a 10.1cm-wide elastic strap placed over 14 objects. Each object was suspended; an inflated neonatal blood pressure cuff was placed atop the object with the strap over the bladder; and strap ends were connected below with 4.54kg weights attached at 20-second intervals to 27.24kg.

Pressure-response curves differed by strap, thigh aspect (medial, lateral, ventral, dorsal; n = 2 subjects; p < .0001); subject (medial thigh; n = 3 subjects; p < .0001); and object (thighs; small and large pool noodles ± central metal rod, foam yoga roller, coffee can, 20% ballistic gel cylinder [Gel; Clear Ballistics; clearballistics.com] with central metal tubing, rolled pair of 5mm yoga mats ± central metal rod, hemorrhage-control training thigh [Z-Medica], sand-filled training manikin limb [Drumm Emergency Solutions]; p < .0001). Compliance, circumference, support techniques, and surface interactions, especially with the 10.1cm-wide elastic strap, affected pressure responses: smaller circumference, lower compliance, and lower surface coefficient of friction were associated with higher pressure/force applied.

Different objects have different pressure-response curves. This may be important to acquisition and retention of limb tourniquet skills and is important for systems for certifying tourniquets.