Kragh JF, Aden JK, Dubick MA. 20(3). 44 - 51. (Journal Article)
Abstract
Background: Given little data to assess guidelines, we sought a way to exchange one type of intervention, field tourniquet use, for another, use of a pressure dressing. The study purpose was to test performance of controlling simulated bleeding with a stepwise procedure of tourniquet conversion. Methods: An experiment was designed to assess 15 tests of a caregiver making tourniquet-dressing conversions. Tests were divided into trials: tourniquet use and its conversion. In laboratory conditions, the tourniquet trial was care under gunfire; then, the conversion trial was emergency healthcare. A HapMed Leg Tourniquet Trainer simulated a limb amputation. An investigator provided healthcare. Results: Mean (± standard deviation [SD]) test time and blood loss were 9 ± 3.6 minutes and 334 ± 353.9mL, respectively. The first test took 17 minutes. By test number, times decreased; the last six took ≤7 minutes. All tourniquet trials controlled bleeding. Mean (±SD) tourniquet pressure and blood loss were 222 ± 18.0mmHg and 146 ± 40.9mL, respectively. Bleeding remained uncontrolled in one conversion. Initial attempts to wrap a dressing were effective in 73% of tries (n = 11 of 15). Four of 15 wrap attempts (27%) were repeated to troubleshoot bleeding recurrence, and the first three tests required a repetition. Mean (±SD) dressing pressures and blood losses were 141 ± 17.6mmHg and 188 ± 327.4mL, respectively. Unsatisfactory conversion trials had a dressing pressure <137mmHg. Dressings and wraps hid the wound to impair assessment of bleeding. Conclusions: In testing a method of converting a limb tourniquet to a pressure dressing, the caregiver performed faster with experience accrual. The tourniquet results were uniformly good, but conversion results were worse and more varied. Simulating conversion was disappointing on a manikin and indicated that its redesign might be needed to suit this method. The procedural method constituted a start for further development.
Keywords: bleeding control and prevention; bandage; dressing, emergency; skill; tourniquet
Hingtgen E, Wall PL, Buising CM. 20(3). 52 - 61. (Journal Article)
Abstract
Background: The OMNA Marine Tourniquet is a 5.1cm-wide, simple redirect buckle, hoop-and-loop secured, ratcheting tourniquet designed for storage and use in marine environments. This study evaluated self-application effectiveness and pressures. Methods: Triplicate secured, occlusion, and completion pressures were measured during 60 subjects pulling down or up thigh applications and nondominant, single-handed arm applications. Arm pressure measurements required circumferences =30cm. Results: Thirty-one subjects had arm circumferences ≥30cm. All 540 applications were effective; 376 of 453 applications had known secured pressures >150mmHg (89 of 93 arm). Thigh down versus up pulling directions were not different (secured, occlusion, and completion pressures and ladder tooth advances). Occlusion pressures were 348mmHg (275-521mmHg) for combined thighs and 285mmHg (211-372mmHg) for arms. Completion pressures were 414mmHg (320-588mmHg) for combined thighs and 344mmHg (261-404mmHg) for arms. Correlations between secured pressures and occlusion ladder tooth advances (clicks) were r2 = 0.44 for combined thighs and 0.68 for arms. Correlations between occlusion pressures and occlusion clicks were poor (r2 = 0.24, P < .0001 for combined thighs and r2 = 0.027, P = .38 for arms). Conclusions: The OMNA Marine Tourniquet can be self-applied effectively, including one-handed applications. Occlusion and completion pressures are similar to reported 3.8cm-wide Ratcheting Medical Tourniquet pressures.
Keywords: tourniquet; hemorrhage; first aid; emergency treatment