REDUCING FIRE GROUND INJURIES DUE TO HEAT STRESS. Leading Community Risk Reduction

Transcription

1 Reducing Fire Ground Injuries 1 REDUCING FIRE GROUND INJURIES DUE TO HEAT STRESS Leading Community Risk Reduction Reducing Fire Ground Injuries Due to Heat Stress at Hanover Park Fire Department Craig A. Haigh Hanover Park Fire Department, Hanover Park, Illinois November 2006

2 Appendix B Not Included. Please visit the Learning Resource Center on the Web at to learn how to obtain this report in its entirety through Interlibrary Loan.

3 Reducing Fire Ground Injuries 2 Certification Statement I hereby certify that this paper constitutes my own product, that where the language of others is set forth, quotation marks so indicate, and that appropriate credit is given where I have used the language, ideas, expressions or writings of another. Signed:

4 Reducing Fire Ground Injuries 3 Abstract The problem was the number of illnesses/injuries experienced by Hanover Park Fire Department which are attributable to heat stress. The purpose of this research was to investigate heat stress and assess methods to reduce its impact. Descriptive research was conducted using literature reviews and surveys to find: 1. Types of injuries/illnesses firefighters are incurring at structure fires or live fire trainings 2. Physical and physiological strains associated with heat stress 3. Methods that can be implemented to prepare firefighters for the physical demands of heat stress 4. Rehab programs other fire departments are using The results of the information gathered created recommendations for training, health screening/wellness programs, and standardized rehab policies.

5 Reducing Fire Ground Injuries 4 CONTENTS Abstract...3 List of Tables...5 Table of Figures...6 Introduction...7 Background and Significance...9 Literature Review...11 Procedures...23 Results...25 Discussion...33 Recommendations...35 References...37 Appendix A--REHABILITATION POLICY...39 Appendix B--FDIC REHABILITATION CLASS...48

6 Reducing Fire Ground Injuries 5 List of Tables Table 1 Number of Fires...9 Table 2--Wet Bulb Globe Temperature Index...16 Table 3--Injuries to Hanover Park Firefighters...25 Table 4--First-Aid Reports for Hanover Park Firefighters...26

7 Reducing Fire Ground Injuries 6 Table of Figures Figure 1 Possible Causes of Heart Attacks in Firefighters...14 Figure 2 Core Body Temperatures...19

8 Reducing Fire Ground Injuries 7 Introduction Firefighting by its very nature exposes firefighters to heat extremes and the products of combustion in the course of a day s work. Firefighters undergo a combination of physical and physiologic strains resulting from heavy muscular activity, working under conditions of emotional strain, hot and hostile work environments and heavy protective equipment. (Denise L. Smith & Craig A. Haigh, 2006) This protective equipment is designed to reduce the potential injuries caused by exposure to this environment. However, the protection garnered by these garments, including breathing apparatus, is offset by the great potential to produce high body core temperatures due to the reduced ability for the body to naturally eliminate internal heat via sweating and exhalation of heated respiratory gases. Protective equipment creates a microclimate inside the firefighters gear and next to their skin, thereby rapidly reaching a humidity of nearly 100 percent. This microclimate, coupled with temperatures inside a burning structure routinely reaching in excess of 800 F, quickly generates a variety of health problems including dehydration, cardiovascular strain and thermal strain. (Denise L. Smith & Craig A. Haigh, 2006) Hanover Park Fire Department has experienced a number of firefighter illnesses and injuries while operating on the fireground which can be attributed to the heat stress and strain associated with fire ground operations. The purpose of this research paper is to analyze heat stress and assess methods to reduce the number of illnesses and injuries caused by heat stress to Hanover Park Firefighters. This will be accomplished by focusing on methods to better prepare the firefighter to physically operate within heated environments. Research also focuses on the identification of best practices for managing the impact of heat stress on firefighters working an incident, including on-scene rehabilitation programs.

9 Reducing Fire Ground Injuries 8 Descriptive research methods are used to answer the following questions: 1. What types of injuries/illnesses have Hanover Park Firefighters incurred following a working structure fire or live fire training? 2. What are the physical and physiological strains associated with heat stress caused by fireground operations? 3. How can we better prepare firefighters for the physical demands of heat stress caused by fireground operations? 4. What rehab programs are other fire departments using?

10 Reducing Fire Ground Injuries 9 Background and Significance The Hanover Park Fire Department is a municipal organization providing emergency services to the Village of Hanover Park and the Hanover Park Fire Protection District (formerly known as the Ontarioville Fire Protection District). Prior to 2000, the organization was governed by a fire protection district board and levied property tax for provision of services; however, in July 2000, the district was absorbed by the Village of Hanover Park whereby all assets including personnel were transferred to municipal control. The Village is located in the western suburbs of the Chicago metro area with the department serving a population base of 40,000 residents. The department is an active participant with both MABAS (Mutual Aid Box Alarm System) Divisions II and XII and responds to more than 2,600 emergency calls annually. Due to MABAS agreements for auto aid response, it is important to note that the population base served by Hanover Park companies on a first alarm basis exceeds 120,000 people. A five-year average shows Hanover Park companies responding to 73 working fires annually (this includes auto and mutual aid response). Table 1 Number of Fires Year Number of Fires

11 Reducing Fire Ground Injuries 10 During this same time period, fifty (50) firefighters filed accident reports for injuries or illnesses that occurred while operating at the scene of an emergency incident, during training, and for medical exposures. These accident s generated 22,649 hours of work comp sick leave due to the injury. In the 78-year history of Hanover Park Fire Department, only one line-of-duty cardiac event resulted in a myocardial infarction. The firefighter was left with limited cardiac output necessitating his retirement with a full disability pension. This event in 1998 led fire administration to increase the available physical fitness equipment but failed to develop a comprehensive health and wellness program. Hanover Park Fire Department has been blessed to have never experienced a line-of-duty death. Information obtained through research for this project will help educate firefighters on the physical and physiological demands of firefighting and help determine appropriate methods for reducing fire ground illnesses and injuries caused by heat stress, including best practices for the development of on-scene rehabilitation and medical monitoring protocols. This research relates to the USFA goal of reducing the loss of life from fire to firefighters. It also links to the Leading Community Risk Reduction class through its assessment and identification of a problem and then taking action to correct this problem through education and engineered practices.

12 Reducing Fire Ground Injuries 11 Literature Review The review of literature for this project focused on the findings of research conducted on heat stress and the associated physical and physiologic response of the human body. Fire Service trade journal articles were reviewed as well as published materials from exercise and sports medicine scientists, immunologists and psychologists, and researchers from the United States Military, the British Royal Navy, the Zimbabwe Army, and the Singapore Armed Forces. In general, very little information currently exists specifically related to the effects of heat stress in firefighters. Much is known about the physical and physiological effects of exercise in heated environments, but little focus has been applied to fire suppression activities while working in thermal-resistant protective equipment. Much of the existing scientifically-based material comes from the University of Illinois Fire Service Institute where Denise L. Smith, PhD, has been conducting on-going studies since the early 1990s. Additionally, the City of Chicago commissioned a study in 1991 through the University of Wisconsin Milwaukee looking specifically at the relationship between heart rate and oxygen consumption to determine the energy expenditure requirements of physically demanding tasks. During the Falklands War, the British Royal Navy investigated the effectiveness of hand and forearm immersion in water as a technique for reducing heat stress in shipboard firefighters, and the Workplace Safety and Insurance Board of Ontario conducted a study on the heat stress of wearing firefighting protective clothing. These studies, coupled with research from exercise physiologists, can assist us in understanding the detrimental effects of exercise in heated environments by painting a clearer picture of the body s response.

13 Reducing Fire Ground Injuries 12 Loring Rowell, Chairman of the University of Washington Department of Physiology/Biophysics writes: Probably the greatest stress ever imposed on the human cardiovascular system is the combination of exercise and hyperthermia. Together these stresses can present lifethreatening challenges, especially in highly motivated athletes who drive themselves to extremes in hot environments. (Rowell, 1986) Although Dr. Rowell is speaking of highly motivated endurance athletes, his quote could just as easily apply to firefighters. Ross, McBride, and Tracy (Ross, 2004) report that heat stress occurs when the body s internal core temperature rises above its normal level. It is a result of internal, metabolic heat buildup (from wearing bunker gear) and external stress from environmental factors while wearing personal protective equipment. Heat stress can be induced by any number of factors but most commonly high ambient air temperatures; high humidity; physically demanding work; and the type, style, and breathability of protective equipment. A firefighter s fitness level, body composition and psychological disposition are all contributing factors as well. Studies conducted at the University of Illinois Fire Service Institute discuss the relationship between heat stress and stroke volume. Firefighters working in protective equipment inside heated environments force their cardiovascular and body systems to compete for blood flow. The metabolically active muscle groups require oxygen carried by the blood to support the heavy muscular work, while the skin works to shunt blood away from the core for cooling in order to maintain the thermoregulatory system of the body. The vital organs of the brain and heart also require blood flow in order to sustain consciousness and vegetative functions. These cardiovascular demands are exacerbated by the tremendous fluid loss caused

14 Reducing Fire Ground Injuries 13 from profuse sweating and vasodilatation. The studies indicate that the hearts stroke volume (the amount of blood pumped with each beat of the heart) is substantially decreased during firefighting which is most likely caused from a combination of decreased venous return (caused by pooling of blood in the working muscles of the extremities) and profuse sweating which reduces the blood s plasma level. In addition to the reduced plasma level, Fibrinogen, a factor in blood clotting, is increased during firefighting. This increase elevates the risk of the body developing a clot within the circulatory system. Although this study does not show a definitive link to fireground cardiac incidents, it does identify potential areas of concern. (Smith, 2001) According to reports from the United States Fire Administration and National Fire Protection Association approximately 45 percent of line-of-duty deaths occur annually from heart attacks. (Fahy, 2004) (United States Fire, 2002) Dr. Denise Smith stated in an interview with the author that although most of these deaths can be related to long-term disease progression; it is likely however that the stress associated with firefighting can and does serve as the trigger for many cardiac related events. (Denise L. Smith, personal communication, February 8, 2006)

15 Reducing Fire Ground Injuries 14 Figure 1 Possible Causes of Heart Attacks in Firefighters Simplified Schematic of Possible Causes of Heart Attack in Firefighters Profuse Sweating Increased Body Temperature Activation of Sympathetic Nervous System Decreased Plasma Levels Altered Electrolytes Increased Blood Viscosity Changes in Heart Rate & Blood Pressure Circulatory Shock Arrhythmias Clot Formation Plaque Disruption Heart Attack The Chicago Fire Department commissioned a study in 1991 looking at oxygen consumption during fire suppression. Ten male firefighters were tested to determine their oxygen consumption and heart rates while performing simulated fire suppression drills. The men were initially tested on a treadmill to determine rate and consumption, and then moved to the simulated suppression activity where a marked reduction in oxygen consumption was noted compared to the elevated heart rate. The findings indicated that the heart rate energy expenditure as compared to oxygen consumption is not straightforward and hard to predict in fire suppression settings. Based on the findings of this study, researchers believe that firefighters develop over time a higher relative intensity work threshold (acclimation) compared to non-firefighters as it relates to required fire suppression tactics. In essence, the experienced firefighter figures out

16 Reducing Fire Ground Injuries 15 how to accomplish the required tasks with the least amount of physical exertion required. This is believed to be a learned muscle memory practice used to minimize the physical difficulty of the job and the associated heat stress. (Sothmann, 1991) Bodil Nielsen of the University of Copenhagen, Denmark agrees that repeated exposures to hot environments leads to acclimation and the delayed onset of fatigue. He goes on to say that the physical signs of heat stress continue to be present, yet somewhat slowed and reduced. The subjects do not feel as fatigued because the mind is tricked into believing that these conditions are routine. (Nielsen, 1994) Dr. Robert Glatz, Retired Medical Director of the King (NC) Fire Department presented the following as part of a firefighter safety and survival course at the 1998 Stokes County Fire School. (Glatz, 1998) Glatz recommended that firefighters engage in a regular physical training regiment since frequent exercise increases water and blood plasma levels by 10%-12%. Muscles cells contain 75% water while fat cells contain 25% water. In addition fat insulates the body there-by eliminating the body s ability to cool. Continued aerobic physical training will increase the efficiency and effectiveness of the body s cooling systems, reduce body fat, allow the firefighter to carry more water, sweat less, achieve greater cooling, and lose less salt thereby allowing faster re-hydration & recovery. He also suggested a carbohydrate-rich diet since carbohydrates give us the energy to work and sweat. A 60% carbohydrate rich diet (fruits, vegetables, breads, cereals, grains, rice and pastas) will increase the firefighter s ability to store energy and water. Finally, he recommends acclimation to working in heat. He suggests that if you are required to work in turnout gear, you need to train in turnout gear. This issue of acclimation has been readily studied as it relates to athletes competing in heated environments, workers who are subject to extreme temperatures (both heat and cold), and

17 Reducing Fire Ground Injuries 16 most notably, with soldiers who are required to perform within the most extreme of conditions. The Singapore Armed Forces Soldier Performance Centre, through repeated study of soldiers working in hot environments, concluded that acclimation can be produced in terms of core body temperature and sweat loss. Heart rate acclimation necessitates cardiovascular training, but when coupled with training in a heated environment, the soldiers perform better and longer with less detrimental effects due to heat stress. (Lin, 1997) The United States Military agrees; however, heat stress studies ongoing since 1950 have established that acclimation, cardiovascular fitness and hydration only go so far in the prevention of the effects of detrimental heat stress. Studies have demonstrated that heat illness rates are reduced by restricting the physical activity and dress of soldiers when the wet bulb globe temperature index (WBGT) exceeds 80 F. The military defines the WBGT as a weighted temperature index that takes into account air temperature, air movement, humidity and radiant heat exchange. This index was originally developed to predict sweat rates thereby predicting soldier heat stress. (Kark, 1996) For the last several decades military command policy has established a standard manner in which non-combat physical activity has been modified based on the WBGT. Table 2--Wet Bulb Globe Temperature Index WBGT Levels Physical Activity Modification F Green Flag Exercise continues with caution F Yellow Flag Strenuous exercise suspended for first phase recruits F Red Flag Strenuous exercise suspended for all recruits 90 F Black Flag Suspension of all out door physical activity

18 Reducing Fire Ground Injuries 17 This modification has significantly reduced heat stress injuries. (Kark, 1996) However, during combat situations, usage of the WBGT system is not practical and systems of rehabilitation and fluid replacement become a necessity. Couple this with the need for chemical protective equipment as exhibited in the first Gulf War, and the heat stress issues faced by the military begins to approach the fire service situation. In these situations, the military has instituted protocol for cooling with ice water in the field as well as rehydration. If transport for medical care is required, treatment with rapid IV fluids is initiated including close monitoring of vital signs and continued cooling while being transported to a medical care facility or field hospital. The Zimbabwe Army Health/Environmental Medicine Unit in cooperation with the Department of Anatomy and Physiology at the University of Dundee, United Kingdom, conducted research on the benefits of consuming water alone or a dextrose with electrolytes drink. Results showed the critical need for continued fluid replacement during periods of exercise/work in hot conditions and better achievement of whole body water and electrolyte balance when electrolyte-containing drinks are ingested. Test subjects also reported a delay in the feeling of fatigue with the utilization of electrolyte containing drinks. (Mudambo, 1997) The NFPA 1584 (Recommended Practice on the Rehabilitation of Members Operating at the Incident Scene and Training Exercises 2003 Edition) standard recommends that firefighters consume a 50/50 mix of water and an electrolyte-containing sports drink 1 hour into the incident and additional electrolyte-containing drinks after every 2-3 bottles of water throughout the life of the incident. (NFPA 1584., 2003) Sports drinks work well to replace lost electrolytes, but care must by taken to ensure that their concentrations and osmolarity is less than 350 mosm/liter. Beverages with too high an osmolarity may actually draw fluids out of the cells in an effort to

19 Reducing Fire Ground Injuries 18 make it less concentrated, hence the NFPA recommendation of mixing the drinks 50/50 with water. (Verfuss, 2004) Typically, once a firefighter departs from a heated environment, their protective clothing is removed and the body is allowed to cool through evaporation. (Ross, 2004) However, the British Royal Navy conducted testing during the Falklands War with firefighters wearing protective equipment while exposed to heated environments; then hand and forearm immersion was used to lower core body temperatures. By immersing the hands in water between 50 F and 86 F, a significant lowering of core temperature was noted within 10 minutes. (Ross, 2004) The Royal Navy continued their research on hand and forearm immersion with much success during the Persian Gulf operations where soldiers wearing chemical protective clothing were cooled using hand immersion to prevent heat stress injuries. (House, 1997) The DefenCe Research and Development Canada (DRDC) Study evaluated similar data to the Chicago study and the Royal Navy study in an attempt to determine work limits for firefighters wearing protective clothing, to establish hydration strategies and to evaluate cooling strategies including passive cooling, misting fans and forearm immersion. Using this information, the group hoped to develop standards for how long a firefighter could and should work as well as measurable standards indicating when they are ready for release from rehab and available for another strenuous assignment. Suspecting that body core temperature and heart rate would be good indicators of overall physical condition, these two factors were evaluated. It was discovered that heart rate is not a useful method to assess recovery during rehab since heart rate rapidly returns to near normal levels, making the firefighter feel much better, yet core body temperatures still remained high. In fact, without active cooling methods (forearm immersion or misting fans), core temperatures continued to rise over a 30-minute rest period even with a

20 Reducing Fire Ground Injuries 19 marked decrease in heart rate. (McLellan, September 2003) This finding is consistent with Dr. Smith s research at the Illinois Fire Service Institute where she discovered that core temperatures continue to rise even after firefighters have been removed from the heated environment, protective clothing removed and placed in an air conditioned ambulance in a semi-fowlers position on an ambulance cot. (Smith, 2006) Figure 2 Core Body Temperatures 39 Core Body Temperatures after 10 Minute Recovery Trectal P re Trial 1 Trial 2 Trial 3 10 min rec Also in agreement, Dr. Smith suggests pushing fluids during the periods of rest (changing an SCBA cylinder, waiting for a new job assignment, etc.) and within the rehab sectors. (Smith, 2006) The DefenCe Research indicates a 20 percent performance improvement following fluid replacement as compared to no fluid intake while resting or in rehab. (McLellan, September 2003) It was also conclusively identified that rehab times are different for all firefighters based on individual age, sex, physical condition, psychological health, body make-up, environmental conditions, and the given emergency situation. Therefore, it is impossible to establish a set rest period encompassing all firefighters in every situation. Based on this, rehab sectors must include rehydration, cooling and medical monitoring. (Denise L. Smith, personal communication, February 8, 2006)

21 Reducing Fire Ground Injuries 20 In addition to the loss of circulating volume due to dehydration causing a decreased stroke volume and increased viscosity of the blood, the elevated core temperatures decrease the body s ability to process information and make rational decisions. A study conducted by the Human Sciences Laboratory, Transvaal and Orange Free State Chamber of Mines in Johannesburg, South Africa, looked at heat reactions of male and female Caucasians working in heated environments. Subjects were tested using a stair machine at a rate of 12 steps per minute to ensure a standardized continuous work rate of 1,560 ft lb/min. The tests were conducted in a climatic controlled tent at F for 4-hours per day over an 11-day period. Male test subjects were dressed in shorts and female subjects in bikini type clothing. Subject s core temperatures were measured using rectal probes and the testing was stopped when rectal temperatures exceeded 104 F or when the subject became giddy or exhibited signs of exhaustion or distress due to headache or abdominal pain. Researchers discovered that heart rates and rectal temperatures rose to very high levels much more rapidly in the females and that they produced considerably less sweat in the first hour of the tests than their male counterparts. However, the sweat rates became much closer in the second and subsequent hours. Important is that both sexes were psychologically affected showing signs of marked aggression and irritability and loss of their usual social inhibitions. One man had hysterical manifestations and several of the females broke down and wept. Most subjects complained of epigastric/precordial pain, tingling of the extremities, difficulty in breathing, swallowing, throbbing headaches and giddiness. (Wundham, 1964) Additional research on cognitive function within heated conditions (104 F) shows that simple reaction time and accuracy significantly deteriorates as the core temperature increases. (Razmjou & Kjellberg, 1992) A study conducted by the Department of Psychological Sciences/Center for Human Sciences, Defense Research Agency in Farnborough, Hampshire,

22 Reducing Fire Ground Injuries 21 UK determined that the neural conduction velocity decreases as the temperature rises causing a marked reduction in memory and accuracy of assigned tasks. (Frim, 1994) In addition to cognitive function disorders, the body responds chemically to heat stress in a variety of negative ways. Blood tests of firefighters participating in live fire evolutions as part of the Illinois Fire Service Institute s ongoing study indicates the body experiences several negative effects. Platelet levels increase as does Fibrinogen, and when coupled with reduced plasma levels, the risk of blood clots increase. Especially telling is the fact that Antithrombin III, a protein that helps prevent and regulate blood clotting, is also elevated post evolution. Sodium levels decrease due to the massive dehydration and glucose levels often reduce to levels seen in clinical hypoglycemia. This hypoglycemic or near hypoglycemic state may also contribute to the reduced cognitive function, but this has not yet been specifically studied. Cortisol, a hormone produced by the adrenal gland important for function of the immune system, glucose regulation, vascular tone and bone metabolism and is secreted during periods of stress is also elevated. Cortisol levels post evolution routinely are elevated 100% above pre-activity levels. Additionally a decrease in the bodies immune cells are seen including an increase in leukocyte or white blood cell levels. (Smith, 2006) In order to mitigate or minimize the detrimental affects of heat stress an effective rehabilitation sector is a required fireground tactic. Fire departments need to develop policies that include rest, hydration, active cooling and fueling for operating personnel. (Ross, 2004) Additionally, policies need to be established for medical monitoring including standing medical orders to assist medial personnel assigned to the rehab sector determine the conditions of firefighters. These medical assessments as well as the time in/time out, the amount of fluid

23 Reducing Fire Ground Injuries 22 ingested, types of cooling procedures used as well as nourishment needs to all be tracked. It is recommended that this documentation be maintained as part of the department s permanent records regarding the incident. (Denise L. Smith & Craig A. Haigh, 2006) In summary, the reviewed literature clearly identifies the physical and physiological impact of heat on the human body. This information paints a convincing picture of the negative influences of heat stress and the need to aggressively mitigate its effects. Additionally, this review clarified how little information currently exists that specifically studies the impact on the human body of firefighting. Continued scientific based research is needed in order to fully understand the impact of heat stress on firefighters.

24 Reducing Fire Ground Injuries 23 Procedures The procedures used to derive this applied research project focused on: (1) whether common strains, sprains and falls are related to heat stress events, (2) are Hanover Park firefighters sustaining injuries from heat stress? To answer these questions a comprehensive review of all fire department injury reports, resulting from structure fires or live fire training, was conducted dating back to July of This date was selected based on the availability and completeness of records following the merger of the fire protection district and the municipality. The total number of accidents was calculated, and then broken down into 15 categories. The physical and physiological strains associated with heat stress were identified through the literature review: 1. Core body temperate 2. Hydration levels 3. Blood pressure and pulse rate 4. Rate of perceived exertion 5. Level of consciousness Next, I analyzed current conditions and practices to identify ways to better prepare firefighters for the physical demands of fireground operations. 1. What is our current physical fitness program? 2. Do we have established dietary suggestions to promote good nutrition? 3. Are we utilizing the most appropriate kind of protective equipment to minimize heat stress? If so, is it in good repair? 4. What is the current health status of each employee?

25 Reducing Fire Ground Injuries 24 Finally, I evaluated rehabilitation practices. Did a current rehab policy exist within our department? If so, did it include: 1. Rehydration 2. Body cooling and protection from climate 3. Medical monitoring 4. Rest and recovery period 5. Member accountability How strongly do the firefighters in general embrace the rehab program? Do they believe rehab is needed--that it subsequently reduces line of duty injuries? Meetings were held with each Hanover Park shift to discuss rehab and the beliefs and attitudes of the firefighters. Firefighters were asked the following questions: 1. Do you believe that rehab is an important part of incident management? 2. If so, at what alarm level should a formal rehab sector be established? 3. What components are needed as part of a rehab sector? 4. Does the heat stress associated with firefighting lead to heart attacks? An Illinois Fire Service Institute Library ListServe Survey was conducted as well as a NFA TRADE Survey asking information regarding fire departments rehab practices including copies of their standard operating guidelines. They were also asked to provide insight into stumbling blocks that prohibited the effective use of rehab sectors. Sixteen departments representing thirteen states responded.