Wall PL, Buising CM, Hingtgen E, White A, Jensen J. 21(1). 11 - 17. (Journal Article)
Abstract
Background: Limb position changes are likely during transport from injury location to definitive care. This study investigated passive limb position change effects on tourniquet pressure and occlusion. Methods: Triplicate buddy-applied OMNA® Marine Tourniquet applications to Doppler-based occlusion were done to sitting and laying supine mid-thigh (n=5) and sitting mid-arm (n=3). Tourniqueted limb positions were bent/straight/bent and straight/bent/straight (randomized first position order, 5 seconds/position, pressure every 0.1 second, two-way repeated measures ANOVA). Results: Sitting thigh occlusion pressures leg bent were higher than straight (median, minimum-maximum; 328, 307-403mmHg versus 312, 295-387mmHg, p = .013). In each recipient, the pressure change for each position change for each limb had p < .003. In each recipient, when sitting, leg bent to straight increased pressure (326, 276-415mmHg to 371, 308-427mmHg bent first and 275, 233-354mmHg to 311, 241-353mmHg straight first), and straight to bent decreased pressure (371, 308-427mmHg to 301, 262-388mmHg bent first and 312, 265-395mmHg to 275, 233-354mmHg straight first). When laying, position changes from leg bent first resulted in pressure changes in each recipient but not in the same directions in each recipient. From laying leg straight first, in each recipient changing to bent increased the pressure (295, 210-366mmHg to 328, 255-376mmHg) and to straight decreased the pressure (328, 255-376 mmHg to 259, 210-333 mmHg). Sitting arm bent occlusion pressures were lower than straight (230, 228-252mmHg versus 256, 250-287mmHg, p = .026). Arm position changes resulted in pressure changes in each recipient but not in the same directions in each recipient. Changes in pressure trace character (presence or absence of rhythmically pulsatile traces) and Doppler-based occlusion were consistent with limb position-induced changes in tourniquet pressure (each p ≤ .001 leg, p = .071 arm traces, and p = .188 arm occlusion). Conclusions: Passive limb position changes can cause significant changes in tourniquet pressure. Therefore, tourniquet adequacy should be reassessed after any limb position change.
Keywords: tourniquet; hemorrhage; first aid; emergency treatment
Bailey RA, Simon EM, Kreiner A, Powers D, Baker L, Giles C, Sweet R, Rush SC. 21(1). 44 - 48. (Journal Article)
Abstract
Uncontrolled hemorrhage secondary to unstable pelvic fractures is a preventable cause of prehospital death in the military and civilian sectors. Because the mortality rate associated with unstable pelvic ring injuries exceeds 50%, the use of external compression devices for associated hemorrhage control is paramount. During mass casualty incidents and in austere settings, the need for multiple external compression devices may arise. In assessing the efficacy of these devices, the magnitude of applied force has been offered as a surrogate measure of pubic symphysis diastasis reduction and subsequent hemostasis. This study offers a sensor-circuit assessment of applied force for a convenience sample of pelvic compression devices. The SAM® (structural aluminum malleable) Pelvic Sling II (SAM Medical) and improvised compression devices, including a SAM Splint tightened by a Combat Application Tourniquet® (C-A-T; North American Rescue) and a SAM® Splint tightened by a cravat, as well as two joined cravats and a standard-issue military belt, were assessed in male and female subjects. As hypothesized, compressive forces applied to the pelvis did not vary significantly based on device operator, subject sex, and subject body fat percentage. The use of the military belt as an improvised method to obtain pelvic stabilization is not advised.
Keywords: pelvic ring fractures; pelvic injuries; commercial pelvic compression devices; improvised pelvic compression devices; mass casualty incidents