Violent attacks and related mass casualty events continue to occur, with recent headline incidents such as the Las Vegas Route 91 Harvest Festival shooting, Republican congressional baseball team practice, terror attacks in London and Paris, and the unfortunate reoccurrence of school shootings in the United States. These events underscore the need for first responders to provide immediate lifesaving measures to those injured, especially to stop hemorrhage, and save lives.¹ Although fire departments are exploring ways to enter the warm zone and provide medical care, law enforcement must be the provider of the initial trauma medical care in the field until emergency medical service personnel arrive or the environment is deemed safe for other emergency personnel to enter.

Background to the Research Study

HonorHealth is a Magnet-recognized five-hospital network and medical provider in the greater Scottsdale-Phoenix, Arizona, metropolitan area that encompasses two level one trauma centers. HonorHealth operates a unique Military Partnership Program and Simulation Training Center that provides realistic medical training to members of all branches of the U.S. military, as well as first responders, with a specific focus on battlefield and trauma medicine. Since December 2015, the HonorHealth Military Partnership Simulation Training Center has focused on training law enforcement first responders in hemorrhage control through the proper application of a tourniquet and related field trauma medical response, similar to combat medicine for the military.

As part of this training mission, the HonorHealth Military Partnership Program and Simulation Training Center conducted a quantitative research study to obtain empirical data regarding the physiological effects and responses (blood pressure and heart rate) of sworn police officers who participated in training scenarios that involved responding to an active shooter incident or officer-involved shooting and administering emergency medical care through the field application of a tourniquet to a severely injured officer (high-fidelity human simulator) who has a gunshot wound.

As an initial component of the research, voluntary participants completed a questionnaire survey that included questions about their age, tenure, fitness level, military service, wartime setting deployment, prior medical experience, and prior tourniquet training and related confidence level. Resting blood pressure and heart rate were also recorded during this classroom portion of the training.

The simulation scenario portion involved response to an active shooter scene staged in a convenience store or drug store with simunitions, live actors, and a downed officer (high-fidelity human simulator hemorrhaging from a gunshot wound to the leg). At the end of the live scenario, which lasted about four minutes, participants immediately had their blood pressure and heart rate taken for comparison to their resting rates. In addition, about 25 percent of the participants were fitted with a live heart monitor to wear during the duration of the scenario. Data analysis and results of the physiological effects on the officers in regard to heart rate and blood pressure were released in various publications, including the November 2016 Police Chief and Force Science News #312, as well as in presentations given at the 2016 Arizona Emergency Medical Systems Odyssey Conference and the 2016 Southwest Trauma and Acute Care Symposium.² 

Research Study Data Analysis on Time to Tourniquet Application

Detailed analysis was focused on the time to tourniquet placement as captured in seconds. Time to tourniquet application was measured by a start time beginning at a white line painted on the ground that was approximately six feet from the downed officer and the end time was captured with the successful application of the tourniquet as recorded by the sensors within the high-fidelity human simulator. The participants’ tenures, ages, and fitness levels were compared with the participants’ time to tourniquet.

 Research Results

Descriptive Results of Time to Tourniquet Sample and Empirical Data

The 236 total participants (all sworn Scottsdale Police Officers) encompassed the following demographics:

• 89 percent male
• 11 percent female
• 62 percent 21–40 years old
• 38 percent 41–60 years old
• 70 percent with15 years or less experience
• 28 percent with military experience
• 14 percent with experience being deployed in a war-type setting

Time to Tourniquet Results

Overall Results

Among the total participant population, the mean time for tourniquet application was 42 seconds. When diving deeper into the results, factors related to fitness level, age, and tenure were looked at in relation to the time to tourniquet application. These results gave the average time to tourniquet across three distinct age groups of 21–30, 31–40, and 41 or older, and five tenure groups of 1–5, 6–10, 11–15, 16–20, and 21 or more years of experience.

Factored by Age

The average time to tourniquet in relation to fitness levels and age relayed statistical significance. When examining the empirical data, the time to tourniquet for officers between 21 and 40 years of age with no regular exercise averaged approximately 42 seconds, compared to approximately 34 seconds for officers in the same age group who participated in fitness activities four or more times per week. The ratio of the reduction in time to tourniquet application for officers with higher fitness levels was closely correlated for the other two age groups of officers (31–40 and 41+), as shown in Figure 1.

Factored by Tenure

The average time to tourniquet in relation to fitness levels and tenure also relayed statistical significance. When examining the empirical data, the time to tourniquet for officers with between one and five years of tenure with no regular exercise averaged approximately 43 seconds, compared with a time of approximately 36 seconds for officers of similar tenure who participated in fitness activities four or more times per week. This ratio of the reduction in time to tourniquet application for officers with higher fitness levels was closely correlated for the other four groups of officers sorted by tenure (6–10, 11–15, 16–20, and 20+) as shown in Figure 2.

Conclusion and Items for Consideration

It is clear from the research data that the addition of trauma medicine to an officer’s responsibilities in the field during high-stress situations causes physiological stressors when examining heart rate in relation to tourniquet application.³ The empirical data from this research continues to be examined; however, this latest area of examination demonstrates to a degree of statistical significance that physical exercise four or more times per week when compared with no regular exercise increases police officer performance by reducing the time to tourniquet. When examining total population data, the overall mean time of 42 seconds already allows for the possibility of significant blood loss by the wounded individual. Therefore, it is crucial for agencies to understand what the time difference of 8–10 seconds could be to saving lives. In addition, when examining Figures 1 and 2, it is interesting to note that older or longer tenured officers with high levels of fitness had times close to those of younger officers who do not exercise. Law enforcement leaders must recognize the importance of fitness in relation to successful implementation of medical trauma medicine and the timely application of a tourniquet in the field to save lives.

Notes:

¹ Lenworth M. Jacobs, Jr. “The Hartford Consensus III: Implementation of Bleeding Control,” Bulletin of the American College of Surgeons 100, no. 7 (July 2015).

² Todd Larson and Sarah Hubbard, “Physiological Effects on Police Officers Performing Field Trauma Medicine and Tourniquet Application,” The Police Chief 83, no. 11 (November 2016), 52–56; “Tourniquet Responsibility Brings Extra Stress Load, New Study Finds,” posted by Jesse James Jessup, Force Science News 312; Meg Bergeson and Todd Larson, “Tourniquet Use in the Pre-Hospital Setting” (presentation, Arizona Emergency Medical Systems Odyssey Conference, 2016); Denise Filley and Karen Lewandowski, “The Physiological Stress Response of Law Enforcement During Field Application of Emergency Medical Care” (presentation, Southwest Trauma and Acute Care Symposium, Scottsdale, Arizona, November 11, 2016).

³ Larson and Hubbard, “Physiological Effects on Police Officers Performing Field Trauma Medicine and Tourniquet Application”; “Tourniquet Responsibility Brings Extra Stress Load, New Study Finds”; Bergeson and Larson, “Tourniquet Use in the Pre-Hospital Setting.”