False Alarm Effects in Early Warnings for Emergency Vehicles: Exploring Drivers' Move-Over Behavior.

OBJECTIVE: This study investigated drivers' move-over behavior when receiving an Emergency Vehicle Approaching (EVA) warning. Furthermore, the possible effects of false alarms, driver experience, and modality on move-over behavior were explored. BACKGROUND: EVA warnings are one solution to encourage drivers to move over for emergency vehicles in a safe and timely manner. EVA warnings are distributed based on the predicted path of the emergency vehicle causing a risk of false alarms. Previous EVA studies have suggested a difference between inexperienced and experienced drivers' move-over behavior. METHOD: A driving simulator study was conducted with 110 participants, whereof 54 inexperienced and 56 experienced drivers. They were approached by an emergency vehicle three times. A control group received no EVA warnings, whereas the experimental groups received either true or false warnings, auditory or visual, 15 seconds before the emergency vehicle overtook them. RESULTS: Drivers who received EVA warnings moved over more quickly for the emergency vehicle compared to the control group. Drivers moved over more quickly for each emergency vehicle interaction. False alarms impaired move-over behavior. No difference in driver behavior based on driver experience or modality was observed. CONCLUSION: EVA warnings positively affect drivers' move-over behavior. However, false alarms can decrease drivers' future willingness to comply with the warning. APPLICATION: The findings regarding measurements of delay can be used to optimize the design of future EVA systems. Moreover, this research should be used to further understand the effect of false alarms in in-car warnings.

Recommendations for Placement of Bleeding Control Kits in Public Spaces-A Simulation Study.

OBJECTIVE: Bleeding control measures performed by members of the public can prevent trauma deaths. Equipping public spaces with bleeding control kits facilitates these actions. We modeled a mass casualty incident to investigate the effects of public bleeding control kit location strategies. METHODS: We developed a computer simulation of a bomb exploding in a shopping mall. We used evidence and expert opinion to populate the model with parameters such as the number of casualties, the public's willingness to aid, and injury characteristics. Four alternative placement strategies of public bleeding control kits in the shopping mall were tested: co-located with automated external defibrillators (AEDs) separated by 90-second walking intervals, dispersed throughout the mall at 10 locations, located adjacent to 1 exit, located adjacent to 2 exits. RESULTS: Placing bleeding control kits at 2 locations co-located with AEDs resulted in the most victims surviving (18.2), followed by 10 kits dispersed evenly throughout the mall (18.0). One or 2 kit locations placed at the mall's main exits resulted in the fewest surviving victims (15.9 and 16.1, respectively). CONCLUSIONS: Co-locating bleeding control kits with AEDs at 90-second walking intervals results in the best casualty outcomes in a modeled mass casualty incident in a shopping mall.

What motivates and demotivates emergency response volunteers? A survey-based factor analysis study.

BACKGROUND: Organized volunteer initiatives can reduce response times and improve outcomes in emergencies such as cardiac arrests or fires. Retention of volunteers is important to maintain good coverage and capabilities. The current study explores factors underlying volunteers' motivation to continue as volunteers. METHODS: Data from 5347 active volunteers were collected through an online survey. An exploratory factor analysis was used to identify underlying factors that were then used in a regression analysis to predict intention to continue as a volunteer. Group differences based on, among others, number of alarms and prior professional experience in emergency response were explored. RESULTS: The results showed that the factors community, self-image, and competence were the strongest positive predictors for the motivation to continue, whereas alarm fatigue and negative experience were the strongest negative predictors. Volunteers with professional background had higher competence and lower Alarm fatigue. Volunteers from rural areas and small cities had higher community than those in large cities. CONCLUSIONS: Alarm fatigue can make it hard to retain volunteers, which could be addressed using improved dispatch algorithms. Support after dispatch is important to prevent negative experiences. Finally, increased competence, e.g. through education and training, can improve volunteer's motivation to continue.

The Effects of Stress on Tourniquet Application and CPR Performance in Layperson and Professional Civilian Populations.

OBJECTIVE: The purpose of this study was to compare laypeople's and professional first responders' ability to perform tourniquet application and cardiopulmonary resuscitation (CPR) during calm and stressful circumstances. BACKGROUND: Life-threatening bleeding is a major cause of death that could be prevented by fast and appropriate first aid interventions. Therefore, laypeople are now being trained in bleeding control skills, transforming them from bystanders to immediate responders. However, critics have questioned whether laypeople are able to perform during more stressful conditions. METHOD: Twenty-four laypersons and 31 professional first responders were tested in two conditions: a calm classroom scenario and a stressful scenario consisting of paintball fire and physical exertion. Stress and workload were assessed along with task performance. RESULTS: The experimental manipulation was successful in terms of eliciting stress reactions. Tourniquet application performance did not decline in the stressful condition, but some aspects of CPR performance did for both groups. First responders experienced higher task engagement and lower distress, worry and workload than the laypeople in both the calm and stressful conditions. CONCLUSION: Stress did not affect first responders and laypeople differently in terms of performance effects. Stress should therefore not be considered a major obstacle for teaching bleeding control skills to laypeople. APPLICATION: Tourniquet application can be taught to laypeople in a short amount of time, and they can perform this skill during stress in controlled settings. Concerns about laypeople's ability to perform under stress should not exclude bleeding control skills from first aid courses for civilian laypeople.

The Untrained Public's Ability to Apply the Layperson Audiovisual Assist Tourniquet vs a Combat Application Tourniquet: A Randomized Controlled Trial.

BACKGROUND: Although the Stop the Bleed campaign's impact is encouraging, gaps remain. These gaps include rapid skill decay, a lack of easy-to-use tourniquets for the untrained public, and training barriers that prevent scalability. A team of academic and industry partners developed the Layperson Audiovisual Assist Tourniquet (LAVA TQ)-the first audiovisual-enabled tourniquet for public use. LAVA TQ addresses known tourniquet application challenges and is novel in its design and technology. STUDY DESIGN: This study is a prospective, randomized, superiority trial comparing the ability of the untrained public to apply LAVA TQ to a simulated leg vs their ability to apply a Combat Application Tourniquet (CAT). The study team enrolled participants in Boston, MA; Frederick, MD; and Linköping, Sweden in 2022. The primary outcome was the proportion of successful applications of each tourniquet. Secondary outcomes included: mean time to application, placement position, reasons for failed application, and comfort with the devices. RESULTS: Participants applied the novel LAVA TQ successfully 93% (n = 66 of 71) of the time compared with 22% (n = 16 of 73) success applying CAT (relative risk 4.24 [95% CI 2.74 to 6.57]; p < 0.001). Participants applied LAVA TQ faster (74.1 seconds) than CAT (126 seconds ; p < 0.001) and experienced a greater gain in comfort using LAVA TQ than CAT. CONCLUSIONS: The untrained public is 4 times more likely to apply LAVA TQ correctly than CAT. The public also applies LAVA TQ faster than CAT and has more favorable opinions about its usability. LAVA TQ's highly intuitive design and built-in audiovisual guidance solve known problems of layperson education and skill retention and could improve public bleeding control.

Laypeople perception and interpretation of simulated life-threatening bleeding: a controlled experimental study.

INTRODUCTION: First aid performed by immediate responders can be the difference between life and death in the case of trauma with massive bleeding. To develop effective training programs to teach bleeding control to laypersons, it is important to be aware of beliefs and misconceptions people hold on bleeding and severity of bleeding situations. METHOD: A controlled study was conducted in which 175 American college students viewed 78 video clips of simulated bleeding injuries. The volume of blood present (between 0 and 1900 ml), rate of blood flow, and victim gender were systematically varied within participants. Participants were asked to rate injury severity, indicate the appropriate first aid action, and estimate the amount of time until death for the victim. RESULTS: Though the Stop the Bleed® campaign recommends training laypeople to treat 165 ml of blood loss as life threatening, participants largely rated this volume of blood loss as minimal, mild, or moderate and estimated that the victim had just under one hour to live. Increased blood loss was associated with increased recommendations to use a tourniquet. However, in the 1900 ml conditions, participants still estimated that victims had around 22 minutes to live and approximately 15% recommended direct pressure as the intervention. Severity ratings and recommendations to use a tourniquet were also higher for the male victim than the female victim. CONCLUSIONS: Injury classification, intervention selection, and time to death-estimations revealed that training interventions should connect classifications of blood loss to appropriate action and focus on perceptions of how much time one has to respond to a bleeding. The study also revealed a gender related bias in terms of injury classification and first aid recommendations. Bleeding control training programs can be designed to address identified biases and misconceptions while building on existing knowledge and commonly used terminology.

Mechanical Assessment of Tissue Properties During Tourniquet Application.

INTRODUCTION: Successful 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. METHOD: Six 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. RESULTS: The 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). CONCLUSIONS: Simulation 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.

Visual estimates of blood loss by medical laypeople: Effects of blood loss volume, victim gender, and perspective.

A severe hemorrhage can result in death within minutes, before professional first responders have time to arrive. Thus, intervention by bystanders, who may lack medical training, may be necessary to save a victim's life in situations with bleeding injuries. Proper intervention requires that bystanders accurately assess the severity of the injury and respond appropriately. As many bystanders lack tools and training, they are limited in terms of the information they can use in their evaluative process. In hemorrhage situations, visible blood loss may serve as a dominant cue to action. Therefore, understanding how medically untrained bystanders (i.e., laypeople) perceive hemorrhage is important. The purpose of the current study was to investigate the ability of laypeople to visually assess blood loss and to examine factors that may impact accuracy and the classification of injury severity. A total of 125 laypeople watched 78 short videos each of individuals experiencing a hemorrhage. Victim gender, volume of blood lost, and camera perspective were systematically manipulated in the videos. The results revealed that laypeople overestimated small volumes of blood loss (from 50 to 200 ml), and underestimated larger volumes (from 400 to 1900 ml). Larger volumes of blood loss were associated with larger estimation errors. Further, blood loss was underestimated more for female victims than male victims and their hemorrhages were less likely to be classified as life-threatening. These results have implications for training and intervention design.

Operationalising resilience for disaster medicine practitioners: capability development through training, simulation and reflection.

Resilience has in recent decades been introduced as a term describing a new perspective within the domains of disaster management and safety management. Several theoretical interpretations and definitions of the essence of resilience have been proposed, but less work has described how to operationalise resilience and implement the concept within organisations. This case study describes the implementation of a set of general resilience management guidelines for critical infrastructure within a Swedish Regional Medical Command and Control Team. The case study demonstrates how domain-independent guidelines can be contextualised and introduced at an operational level, through a comprehensive capability development programme. It also demonstrates how a set of conceptual and reflective tools consisting of educational, training and exercise sessions of increasing complexity and realism can be used to move from high-level guidelines to practice. The experience from the case study demonstrates the value of combining (1) developmental learning of practitioners' cognitive skills through resilience-oriented reflection and interaction with dynamic complex open-ended problems; (2) contextualisation of generic guidelines as a basis for operational methodological support in the operational environment; and (3) the use of simulation-based training as part of a capability development programme with increasing complexity and realism across mixed educational, training and exercise sessions. As an actual example of a resilience implementation effort in a disaster medicine management organisation, the study contributes to the body of knowledge regarding how to implement the concept of resilience in operational practice.

Defining a Research Agenda for Layperson Prehospital Hemorrhage Control: A Consensus Statement.

Importance: Trauma is the leading cause of death for US individuals younger than 45 years, and uncontrolled hemorrhage is a major cause of trauma mortality. The US military's medical advancements in the field of prehospital hemorrhage control have reduced battlefield mortality by 44%. However, despite support from many national health care organizations, no integrated approach to research has been made regarding implementation, epidemiology, education, and logistics of prehospital hemorrhage control by layperson immediate responders in the civilian sector. Objective: To create a national research agenda to help guide future work for prehospital hemorrhage control by laypersons. Evidence Review: The 2-day, in-person, National Stop the Bleed (STB) Research Consensus Conference was conducted on February 27 to 28, 2019, to identify and achieve consensus on research gaps. Participants included (1) subject matter experts, (2) professional society-designated leaders, (3) representatives from the federal government, and (4) representatives from private foundations. Before the conference, participants were provided a scoping review on layperson prehospital hemorrhage control. A 3-round modified Delphi consensus process was conducted to determine high-priority research questions. The top items, with median rating of 8 or more on a Likert scale of 1 to 9 points, were identified and became part of the national STB research agenda. Findings: Forty-five participants attended the conference. In round 1, participants submitted 487 research questions. After deduplication and sorting, 162 questions remained across 5 a priori-defined themes. Two subsequent rounds of rating generated consensus on 113 high-priority, 27 uncertain-priority, and 22 low-priority questions. The final prioritized research agenda included the top 24 questions, including 8 for epidemiology and effectiveness, 4 for materials, 9 for education, 2 for global health, and 1 for health policy. Conclusions and Relevance: The National STB Research Consensus Conference identified and prioritized a national research agenda to support laypersons in reducing preventable deaths due to life-threatening hemorrhage. Investigators and funding agencies can use this agenda to guide their future work and funding priorities.

Preliminary Investigation of Civilian Clinician Perspectives & Just-in-Time Guidance for Tourniquet Use to "Stop the Bleed".

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.

Fixation Differences in Visual Search of Accident Scenes by Novices and Expert Emergency Responders.

OBJECTIVE: We sought to investigate whether expert-novice differences in visual search behavior found in other domains also apply to accident scenes and the emergency response domain. BACKGROUND: Emergency service professionals typically arrive at accidents only after being dispatched when a civilian witness has called an emergency dispatch number. Differences in visual search behavior between the civilian witness (usually a novice in terms of emergency response) and the professional first responders (experts at emergency response) could thus result in the experts being given insufficient or erroneous information, which would lead them to arrive unprepared for the actual situation. METHOD: A between-subjects, controlled eye-tracking experiment with 20 novices and 17 experts (rescue and ambulance service personnel) was conducted to explore expert-novice differences in visual search of accident and control images. RESULTS: The results showed that the experts spent more time looking at task-relevant areas of the accident images than novices did, as predicted by the information reduction hypothesis. The longer time was due to longer fixation durations rather than a larger fixation count. CONCLUSION: Expert-novice differences in visual search are present in the emergency domain. Given that this domain is essential to saving lives and also relies heavily on novices as the first link in the chain of response, such differences deserve further exploration. APPLICATION: Visual search behavior from experts can be used for training purposes. Eye-tracking studies of novices can be used to inform the design of emergency dispatch interviews.

Short simulation exercises to improve emergency department nurses' self-efficacy for initial disaster management: Controlled before and after study.

INTRODUCTION: Head nurses at emergency departments often assume responsibility for managing the initial response to a major incident, and to create surge capacity. Training is essential to enable these nurses to perform an effective disaster response. Evaluating the effects of such training is however complicated as real skill only can be demonstrated during a real major incident. Self-efficacy has been proposed as an alternative measure of training effectiveness. PURPOSE: The aim of this study was to examine if short, small-scale computer-based simulation exercises could improve head emergency nurses' general and specific self-efficacy and initial incident management skills. METHOD: A within-group pretest-posttest design was used to examine 13 head nurses' general and specific self-efficacy before and after an intervention consisting of three short computer based simulation exercises during a 1-h session. Management skills were assessed using the computer simulation tool DigEmergo. RESULTS: The exercises increased the head nurses' general self-efficacy but not their specific self-efficacy. After completing the first two exercises they also exhibited improved management skills as indicated by shorter time to treatment for both trauma and in-hospital patients. CONCLUSION: This study indicates that short computer based simulation exercises provide opportunities for head nurses to improve management skills and increase their general self-efficacy.

Effects of a retention interval and refresher session on intracorporeal suturing and knot tying skill and mental workload.

BACKGROUND: The effects of refraining from practice for different intervals on laparoscopic suturing and mental workload was assessed with a secondary task developed by the authors. We expected the inability to practice to produce a decrease in performance on the suturing, knot tying, and secondary task and skills to rebound after a single refresher session. METHODS: In total, 22 surgical assistant and premedical students trained to Fundamentals of Laparoscopic Surgery proficiency in intracorporeal suturing and knot tying were assessed on that task using a secondary task. Participants refrained from practicing any Fundamentals of Laparoscopic Surgery tasks for 1 or 5 months. At the time of their return, they were assessed immediately on suturing and knot tying with the secondary task, practiced suturing and knot tying for 40 minutes, and then were reassessed. RESULTS: The mean suture times from the initial reassessment were greater than the proficiency times but returned to proficiency levels after one practice session, F(2, 40) = 14.5, P < .001, partial η2 = .420. Secondary task scores mirrored the results of suturing time, F(2, 40) = 6.128, P < .005, partial η2 = .235, and were moderated by retention interval. CONCLUSION: When participants who reached proficiency in suturing and knot tying were reassessed after either 1or 5 months without practice, their performance times increased by 35% and secondary task scores decreased by 30%. These deficits, however, were nearly reversed after a single refresher session.

Workload differences across command levels and emergency response organizations during a major joint training exercise.

OBJECTIVE: This study reports on an initial test using a validated workload measurement method, the NASA Task Load Index (TLX), as an indicator of joint emergency exercise effectiveness. Prior research on emergency exercises indicates that exercises must be challenging, ie, result in high workload, to be effective. However, this is often problematic with some participants being underloaded and some overloaded. The NASA TLX was used to test for differences in workload between commanders and subordinates and among three different emergency response organizations during a joint emergency exercise. DESIGN: Questionnaire-based evaluation with professional emergency responders. SETTING: The study was performed in conjunction with a large-scale interorganizational joint emergency exercise in Sweden. PARTICIPANTS: A total of 20 participants from the rescue services, 12 from the emergency medical services, and 12 from the police participated in the study (N=44). Ten participants had a command-level role during the exercise and the remaining 34 were subordinates. MAIN OUTCOME MEASURE(S): The main outcome measures were the workload subscales of the NASA TLX: mental demands, physical demands, temporal demands, performance, effort, and frustration. RESULTS: The results showed that the organizations experienced different levels of workload, that the commanders experienced a higher workload than the subordinates, and that two out of three organizations fell below the twenty-fifth percentile of average workload scores compiled from 237 prior studies. CONCLUSIONS: The results support the notion that the NASA TLX could be a useful complementary tool to evaluate exercise designs and outcomes. This should be further explored and verified in additional studies.

Intracorporeal suturing: Transfer from Fundamentals of Laparoscopic Surgery to cadavers results in substantial increase in mental workload.

INTRODUCTION: A spatial secondary task developed by the authors was used to measure the mental workload of the participant when transferring suturing skills from a box simulator to more realistic surgical conditions using a fresh cadaver. We hypothesized that laparoscopic suturing on genuine bowel would be more challenging than on the Fundamentals of Laparoscopic Surgery (FLS)-simulated bowel as reflected in differences on both suturing and secondary task scores. METHODS: We trained 14 surgical assistant students to FLS proficiency in intracorporeal suturing. Participants practiced suturing on the FLS box for 30 minutes and then were tested on both the FLS box and the bowel of a fresh cadaver using the spatial, secondary dual-task conditions developed by the authors. RESULTS: Suturing times increased by >333% when moving from the FLS platform to the cadaver F(1,13) = 44.04, P < .001. The increased completion times were accompanied by a 70% decrease in secondary task scores, F(1,13) = 21.21, P < .001. CONCLUSION: The mental workload associated with intracorporeal suturing increases dramatically when trainees transfer from the FLS platform to human tissue under more realistic conditions of suturing. The increase in mental workload is indexed by both an increase in suturing times and a decrease in the ability to attend to the secondary task.

Cognitive design of a digital desk for the emergency room setting.

Digital desk technology has a still mainly unexplored potential to support the everyday work of collaborating clinicians. This paper presents ER Desk - a digital desk that was designed to specifically support a team of healthcare professionals working in an emergency room setting. The underlying design requirements were elicited in a comprehensive distributed cognition study of paper-based practices in an emergency room of a middle-sized Swedish hospital. We present the user interface and visualization requirements for digital desks for small clinical emergency room teams. Moreover, we discuss key design issues more generally with a focus on supporting team awareness, cognition, and collaborative routines of healthcare personnel working in clinical environments such as emergency rooms and intensive care units.

Spatial judgments in the horizontal and vertical planes from different vantage points.

Todorovic (2008 Perception 37 106-125) reported that there are systematic errors in the perception of 3-D space when viewing 2-D linear perspective drawings depending on the observer's vantage point. Because these findings were restricted to the horizontal plane, the current study was designed to determine the nature of these errors in the vertical plane. Participants viewed an image containing multiple colonnades aligned on parallel converging lines receding to a vanishing point. They were asked to judge where, in the physical room, the next column should be placed. The results support Todorovic in that systematic deviations in the spatial judgments depended on vantage point for both the horizontal and vertical planes. However, there are also marked differences between the two planes. While judgments in both planes failed to compensate adequately for the vantage-point shift, the vertical plane induced greater distortions of the stimulus image itself within each vantage point.