BY P. ALEXANDER DERCHAK AND DARRELL MENDENHALL
Firefighters routinely face severe hazards on-duty and during training exercises. But the single biggest health risk for firefighters isn’t trauma, asphyxiation, or burns. It’s heart attack, often as a result of extreme levels of physical exertion, heat stress, and exposure to toxic substances. In fact, cardiovascular problems alone account for nearly half of all firefighter deaths and injuries, according to a 10-year study published by the United States Fire Administration (USFA).1 Those percentages held even in 2004, when nearly half of all firefighter deaths were attributed to nontraumatic injuries such as heart attacks and strokes.2
The USFA also issued a Special Report that documented an increase in training-related injuries by nearly 21 percent to almost 7,000 injuries between 1987 and 2001.3 Many of these deaths and injuries were attributed to poor physical fitness, with heart attacks being the leading cause of death in training-related incidents.
The risk of heart attack-known medically as myocardial infarction-increases as the firefighter population ages. In 2004, for example, 52 was the average age of firefighters who died from heart attack or stroke. (2) In addition, the job itself generates its own particular risks because it involves long periods of inactivity, followed by abrupt, unpredictable demands for intense exertion and focus. Other factors that exacerbate the risk of heart attack include being overweight, high cholesterol levels, cigarette smoking, lack of regular physical exercise, a family history of heart disease, hypertension, and diabetes. So, what can be done to address the risk and potentially reduce the number of injuries and deaths?
ADDRESSING FIRE SERVICE HEALTH AND SAFETY
The fire service is actively addressing firefighter health and safety needs on many fronts through multiple associations, agencies, foundations, and councils. In 1997, the International Association of Firefighters (IAFF), the International Association of Fire Chiefs (IAFC), and 10 large metropolitan departments across the United States and Canada assembled to form the Fire Service Joint Labor Management Wellness-Fitness Task Force. The mission of the task force is to improve the health and safety of the fire service across North America. To this end, the task force has developed and introduced three major programs: (1) The Fire Service Joint Labor Management Wellness/Fitness Initiative, (2) The Candidate Physical Abilities Test, and (3) The Fire Service Peer Fitness Trainer Certification program.
 1. Photos courtesy of VivoMetrics Government Services. |
In 2004, the National Volunteer Fire Council (NVFC) launched its Heart Healthy Firefighter program. This program is designed to educate firefighters and the communities they serve about the risk of heart attacks and other heart-related dangers inherent in firefighting. Their goal is to reduce heart-related on-duty deaths 25 percent by the year 2008. Additionally, in 2004, the NVFC teamed up with FEMA to develop the new “Health and Wellness Guide for the Volunteer Fire Service.” In 2005, the NVFC also introduced the “Fired Up for Fitness Challenge.” This online interactive program allows firefighters to log on and record their physical activity to earn points and compete for prizes.
In March 2004, the National Fallen Firefighters Foundation, in cooperation with the United States Fire Administration (USFA), hosted a two-day National Firefighter Life Safety Summit. The Summit’s purpose was to produce an agenda of initiatives that would help to achieve the Summit’s objectives of reducing line-of-duty deaths by 25 percent in five years and 50 percent within 10 years. Sixteen initiatives were developed and presented as a means to accomplish these objectives
The National Fire Protection Agency (NFPA) has published many standards directly addressing firefighter health and safety, particularly NFPA 1500, Standard on Fire Department Occupational Safety and Health Program; NFPA 1582, Standard on Medical Requirements for Firefighters and Information for Fire Department Physicians; and NFPA 1583, Standard on Health-Related Fitness Programs for Firefighters.
All of these efforts are valuable and no doubt contribute to the improved health and fitness of firefighters. But the fact remains that heart attack is still the Number 1 risk to firefighters while on-duty and during training exercises. However, new technology is now making it possible to better understand the unique physical demands of firefighting, the training that it requires, and the need to continuously monitor various physiologic parameters of firefighters to help ensure their safety.
LIFESHIRT® SYSTEM
Recent advances in technology, computing, and wireless communications have come together to provide a tool that will greatly increase the understanding of the physiologic demands of fighting fires. A leader in the field of ambulatory (i.e., highly portable) monitoring is VivoMetrics Government Services, Inc., a California-based company that markets the LifeShirt System. The LifeShirt is a miniaturized, ambulatory version of an exercise physiology laboratory that uses a respiratory measurement technology currently used in more than 1,000 hospitals worldwide. The LifeShirt System is able to bring this sophisticated, monitoring technology directly into the field, right to the people who put their lives on the line.
Before entering a high-risk fire or training situation, and even before suiting up with protective or other turnout gear, a firefighter puts on a simple vest that fits underneath other clothing like an undershirt, close to the skin. Connected to the vest are three easy-to-apply heart rate electrodes that are pressed onto the skin of the chest area. The front of the vest is zipped up so that it fits snugly. A push of a button activates the small recording and transmission device also attached to the vest. That’s it-the firefighter is ready to go. Other clothing and necessary gear are then layered on top as needed (photos 1, 2).
From the firefighter’s standpoint, using the LifeShirt System is easy-it’s lightweight and unobtrusive. Most users forget they are wearing it. The complexity of the system is actually engineered into the product in terms of its sensor arrays, wireless transmission hardware, and processing software.
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Here’s how the technology works: The LifeShirt collects data through sensors built into the LifeShirt. They gather continuous, key physiological data, such as heart rate, respiration, activity, and posture. In addition, arterial oxygen saturation, skin temperature, and core body temperature can also be monitored. These data are recorded to a flash card for subsequent analysis and can be transmitted over a wireless system to a remote monitoring station or command center (investigational use only, wireless transmission system is pending Food and Drug Administration clearance). The wireless monitoring station displays a second-by-second picture of each firefighter’s physiologic response to the work of fighting fires, live and in real time.
UNDERLYING SENSOR TECHNOLOGY
The respiratory sensors in the LifeShirt System are wires woven into elastic bands that stretch across the firefighter’s chest and abdomen when the vest is zipped up. As the firefighter breathes in and out, the bands expand and contract to give continuous respiratory measures essential to monitoring overall health and physiologic status. This technology is called “respiratory inductive plethysmography (RIP).”
Accelerometers embedded in the shirt detect level of activity and determine whether the firefighter’s body is upright, at a prone or tilted angle, or lying flat. Heart rate electrodes provide basic ECG measures, which, with the respiratory measures and accelerometers also embedded in the shirt, provide a complete data set on the cardiopulmonary response to the work of firefighting.
MONITORING FIRST RESPONDERS AND
MILITARY PERSONNEL DURING TRAINING
The LifeShirt System has been used by Elk River, Minnesota, and Fairfield, Connecticut, firefighters and haz-mat workers to monitor life signs during training exercises. In each case, the LifeShirt was worn under fire retardant clothing and Level A haz-mat gear to wirelessly transmit key vital signs to incident command centers (photo 3).
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During the Fairfield haz-mat simulation exercise, an 18-wheel tanker truck was lying on its side to simulate a toxic chemical spill. Haz-mat team members wearing LifeShirts cordoned off the area, set up a decontamination center, and dispatched a crew suited in Level A gear to spray foam on the truck to contain toxic vapors. The team then dragged 200-pound mannequins to the “decon” station, where team members in Level B suits cleaned them and performed life-saving techniques. In Elk River, a donated house was set afire, and trainees wearing LifeShirts made multiple entries to knock down the fire. As part of both exercises, commanders monitored their team’s life signs from a remote command truck and noted critical changes.
The LifeShirt’s respiratory sensors have been integrated into the United States Army Research Institute of Environmental Medicine’s (USARIEM) Warfighter Physiological Status Monitor-Initial Capability (WPSM-IC) Program. The WPSM-IC, with its respiratory sensors, will be worn by soldiers in testing and training scenarios, and there are plans to harden the system and deploy it in combat operations. This will enable army medics to remotely assess soldier’s health status and begin triage for medical attention as needed.
The LifeShirt System has also been used by the Walter Reed Army Institute of Research, the U.S. Air Force Institute of Technology, and the Fire Department of New York to address various needs of first responders.
NEW RESEARCH PROJECT IN DEVELOPMENT
The availability of a wearable physiological monitor like the LifeShirt makes it possible to collect a detailed data set describing the responses of firefighters to training and real firefighting. Up to now, what happens inside the turnout gear in training and real fire situations has not been studied, but an important research study is about to get underway.
The Indianapolis (IN) Fire Department (IFD) has long been a leader in the area of firefighter health and safety. It has had a wellness program in place for its firefighters since 1986 that includes a comprehensive annual medical examination and fitness evaluation in which approximately 90 percent of the firefighters participate. The local union has been a strong advocate of this program throughout.
Public Safety Medical Services (www. publicsafetymed.com) is a private occupational medicine clinic located in Indianapolis and Cincinnati that provides services exclusively to fire, police, and sheriff’s departments. Public Safety Medical Services is the medical provider for the IFD as well as more than 180 other departments throughout Indiana and Ohio.
The IFD and other surrounding township departments and Public Safety Medical Services have formed a coalition with researchers from the University of Indianapolis, Indiana University/Purdue University at Indianapolis, and VivoMetrics Government Services to launch a Firefighter Physiologic Surveillance Research Project. “Being able to gain a better understanding of the unique physical demands that firefighters must endure on a daily basis could have a significant impact on our ability to better prepare our firefighters for, and protect them from, the hazards of our occupation,” says IFD Chief James Greeson.
The purpose of this study is to obtain a better understanding of real-time firefighter physiology that will result in improved intervention and training programs and contribute to a reduced incidence of cardiac-related deaths in the fire service. This research project will consist of three distinct phases:
Phase 1: Gather continuous, detailed cardiopulmonary physiologic data during live fireground operations and simulated training operations to describe the normal range of physiologic responses and potentially identify response characteristics that may warn of an impending negative health event such as heat injury or myocardial infarction. Identify criteria for proactive intervention, rehabilitation, and reentry to fireground operations.
Phase 2: Analyze data to determine minimal physical fitness characteristics and an ideal physical conditioning program for optimal performance on the fireground.
Phase 3: Develop, implement, and test physical conditioning programs for firefighters.
“Being able to capture and evaluate physiologic data while firefighters perform live fireground or other emergency operations will help us to better understand the true unique physical demands of our occupation and, subsequently, better prepare our brothers and sisters to meet those demands and protect them from the risks of adverse physical outcomes,” according to Mike Reeves, IAFF Local 416 president.
In another article, we will present and discuss data collected at the FDIC held in Indianapolis April 11-16, 2005. Firefighters there volunteered to wear the LifeShirt System while participating in the flashover simulations and firefighter safety and survival drills during the Hands-On Training (H.O.T.) classes. We also will discuss in more depth the Firefighter Physiologic Surveillance Research Project.
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The combination of research and firefighting expertise provided by PSMS and the data collection capabilities now available present an opportunity to advance the understanding of the physiologic stresses faced by firefighters. This advance will make it possible to train and manage firefighters to better ensure their safety and improve their ability to get the job done. ■
Endnotes
1. “Firefighter Fatality Retrospective Study,” United States Fire Administration, April 2002.
2. “Firefighter Fatality Figures Show 107 On-Duty Deaths in 2004,” press release, United States Fire Administration, January 5, 2005.
3. “Trends and Hazards in Firefighter Training,” United States Fire Administration, May 2003.
