Kragh JF, Wright-Aldossari B, Aden JK, Dubick MA. 19(2). 41 - 47. (Journal Article)
Abstract
Background: To investigate questions about application of emergency tourniquets in very young children, we investigated practices of Combat Application Tourniquet (C-A-T) use on a simulated infant-sized limb to develop ways to improve readiness for caregiving. Methods: This study was conducted as investigations of C-A-Ts used by two individuals in deliberate practice. The practice setup simulating a limb of infants aged 3-5 months included a handrail (circumference, 5.25 in.). This setup needed a specific modification to the instructions for use to adhere the band between the clips. Each user performed 100 practices. Results: With accrual of experience, application time was shorter for each user, on average in a power law of practice, and more ease was associated when less time was taken to apply the tourniquet. The ease of use was associated with accrued experience through deliberate practice of a tourniquet user while under coached learning. A check of tourniquet fit on a 4.25-in. limb also entailed the modification used in the 5.25-in. limb. However, an additional modification of wrapping the band in a figure-8 pattern around the rod was needed because the rod and clip could not meet. The fit on a 3.25-in. limb was impracticable for a workaround. Tourniquet use was harder for smaller limbs (i.e., 4.25 in. and 3.25 in.). A map of tourniquet fit was sketched of which sized limbs were too big, too small, within the fit zone, or at its borders. Conclusion: C-A-Ts mechanically fit the simulated limbs of infants aged 3-5 months, and C-A-T use was practicably easy enough to allow experienced users to fit tourniquets to limbs well using a specific modification of the routine technique. The findings and knowledge generated in this study are available to inform researches and developments in best preparation practices for instructing first aid.
Keywords: Combat Application Tourniquet; limb tourniquet; Stop the Bleed; medical device; combat injury first aid; use instruction; resuscitation; emergency
Wall PL, Buising CM, Donovan S, McCarthy C, Smith K, Renner CH. 19(2). 48 - 56. (Journal Article)
Abstract
Background: Appropriate strap pressure before tightening-system use is an important aspect of nonelastic, limb tourniquet application. Methods: Using different two-handed techniques, the strap of the Generation 7 Combat Application Tourniquet (C-A-T7), Tactical Ratcheting Medical Tourniquet (Tac RMT), Tactical Mechanical Tourniquet (TMT), Parabelt, and Generation 3 SOF® Tactical Tourniquet-Wide (SOFTTW) was secured mid-thigh by 20 appliers blinded to pressure data and around a thigh-sized ballistic gel cylinder by gravity and 23.06kg. Results: Pulling only outward (90° to strap entering buckle) achieved the lowest secured pressures on thighs and gel. For appliers, the best holding location was above the buckle, and the best strap-pulling direction was tangential to the thigh or gel (0° to strap entering buckle). Preceding tangential pulling with outward pulling resulted in higher secured pressures on the gel but did not aid appliers. Appliers generally did not reach secured pressures achievable for their strength. Of 80 thigh applications per tourniquet, 77 C-A-T7, 41 Tac RMT, 35 TMT, 16 Parabelt, and 10 SOFTTW applications had secured pressures greater than 100mmHg. Conclusions: The default for best tourniquet strap-application technique is to hold above the buckle and pull the strap tangential to the limb at the buckle. Additionally, neither strength nor experience guarantees desirable strap pressures in the absence of pressure knowledge.
Keywords: tourniquet; hemorrhage; first aid; emergency treatment