Jonson, Carl‐Oscar

ABSTRACTIntroductionSuccessful tourniquet application increases survival rate of exsanguinating extremity hemorrhage victims. Tactile feedback during tourniquet application training should reflect human tissue properties in order to increase success in the field. This study aims to understand the mechanical properties of a human limb during tourniquet application.MethodSix cadaveric extremities—three uppers and three lowers—were tested from three body mass index groups: low (<19) healthy (19-24), and overweight (>24). Each specimen donned with a tourniquet and mounted to a servo-hydraulic testing machine, which enabled controlled tightening of the tourniquet while recording the tourniquet tension force and strap displacement. A thin-film pressure sensor placed between the specimen and the tourniquet recorded contact pressure. Each limb was tested with the tourniquet applied at two different sites resulting in testing at the upper arm, forearm, thigh, and shank.ResultsThe load displacement curves during radial compression were found to be nonlinear overall, with identifiable linear regions. Average contact pressure under the tourniquet strap at 200N and 300N of tension force was 126.3 (σ = 41.2) mm Hg and 205.3 (σ = 75.3) mm Hg, respectively. There were no significant differences in tissue stiffness or contact pressure at 300N of tension force between limb (upper vs. lower) or body mass index. At 200N of tension, the upper limb had significantly higher contact pressure than the lower limb (P = 0.040). Relative radial compression was significantly different between upper (16.74, σ = 4.16%) and lower (10.15, σ = 2.25%) extremities at 200N tension (P = 0.005).ConclusionsSimulation of tissue compression during tourniquet application may be achieved with a material exhibiting elastic properties to mimic the force-displacement behavior seen in cadaveric tissue or with different layers of material. Different trainers for underweight, healthy, and overweight limbs may not be needed. Separate tourniquet training fixtures should be created for the upper and lower extremities.

The purpose of this panel will be to discuss current research and challenges relating to the work of first and immediate responders. The main discussion of the panel will have panelist challenge human factors researchers to consider new directions of research addressing current capability and knowledge gaps faced by the first and immediate responder communities.

Abstract Objective The American College of Surgeons (ACS) encourages clinicians to provide training to laypeople on tourniquet application. It is unclear whether clinicians are confident in their abilities and equipped with adequate knowledge, skills, and resources. This study aimed to determine surgical trainee knowledge and attitudes regarding tourniquet application and compare the effectiveness of instructions. Methods Thirty surgical trainees performed a tourniquet application simulation using a Combat Application Tourniquet and one of the three instructions sets developed by ACS, Department of Homeland Security, and the tourniquet manufacturer. Participants reported tourniquet knowledge, attitudes, and confidence and discussed the instructions. One instruction set was updated and compared to the original set with 20 new trainees. Results Participants with ACS instructions passed the greatest number of steps (p < 0.01) and completed the task significantly faster compared to those with manufacturer instructions (p < 0.01). Participants (80%) reported favorable views toward tourniquets but 30–60% did not align with to ACS tourniquet guidelines. Focus group participants suggested revisions to the ACS instructions. Comparing the original and revised version of these instructions resulted in no significant improvements. Conclusions ACS instructions provide guidance; however, improvements to tourniquet instruction are needed for success in controlling exsanguinating hemorrhage.

The Stop The Bleed initiative was developed by the Department of Homeland Security to educate lay providers in bleeding reduction strategies. The current study evaluated: (1)three tourniquet instructions using a simulated tourniquet task and (2)participant confidence levels in tourniquet use and lay provider training. Thirty participants with limited clinical experience applied a tourniquet to a simulated limb using one of three instruction sets. Twelve of these participants (40%) participated in a tourniquet training session and focus group to discuss each instruction set. Participants preferred the most simple and pictoral instruction set, and identified opportunities for improvement in each set. Participant confidence in tourniquet use increased significantly following the task and the focus group. After the focus group, participant confidence in instructing lay providers on proper tourniquet use significantly increased. Adding key steps, contextual pictures, and indicators of success to instructions could support lay providers stop the bleed in life-threatening situations.