Implementing Physiological Monitoring in the Fire Service

How will physiological monitoring systems affect command decision-making?

By Dennis C. Wood and Edward J. Dadosky
Published Wednesday, December 26, 2012 | From the February 2013 Issue of FireRescue

According to the U.S. Fire Administration, 46.5% of firefighter fatalities from 2007–2011 were as a result of heart attacks (http://apps.usfa.fema.gov/firefighter-fatalities/fatalityData/statistics). Excerpts from several line-of-duty death (LODD) reports include accounts such as:

  • “Complained to fellow firefighters that he didn’t feel well.”
  • “Fell ill where he was discovered a short time later.”
  • “Fellow firefighters discovered him unconscious in the firehouse.”

In short, many of these firefighters had no idea that they were experiencing a cardiac emergency; they may also have been unaware of underlying factors that contributed to their cardiac-related death.

What if we never had to read about another firefighter death during or after a training exercise that was due to overexertion, leading to a heart attack or stroke? At structure fires, what if firefighters’ vital signs could be remotely and reliably monitored via a minimally invasive garment to be worn under fire gear that would track body temperature, respirations, blood pressure and heart rate—a system designed to alert a third-party monitor to a potential medical emergency for that firefighter? How many firefighter LODDs could such technology prevent every year?

This is not science fiction. Physiological monitoring systems for emergency responders are becoming a reality; several prototypes have been fielded (see sidebar). In the future, incident commanders (ICs) will be able to monitor the physiological health and safety of their personnel in real time.

Physiological monitoring of firefighters will provide a significant improvement in situational awareness on the emergency scene. We will be able to see an objective measure of the firefighters’ health status; in turn, we will be able to intervene for those personnel who may be in distress—even if they do not yet know it, or deny it. Yet this technology will also bring significant challenges. If ICs are going to be prepared to implement this technology as it becomes widely available, fire service leaders must begin to discuss now how it will affect command decision-making in all aspects of fire service operations.

Red, Yellow, Green
In simplest terms, it may be easy to think of physiological monitoring using a “stop light” approach. Rather than overwhelming the IC at the command post with raw data, each firefighter would use the system during everyday activities to establish a baseline, or non-exertion status. From this baseline, the system calculates “how much is too much” for the firefighter, and these levels are programmed into the system so as to alert the IC.

A firefighter operating in the “green” is functioning as a baseline or non-exertion status. They can safely operate in that capacity almost indefinitely. This status is expected during routine station activities or administrative duties.

A firefighter working at a high exertion level would be demonstrated by a “yellow” status. This is the status where our personnel can function, burdened with appropriate protective clothing and significant physical tasks, for a short period of time—usually, the duration of an SCBA cylinder.

A firefighter operating in the “red,” or alarm, level is experiencing a physiological stress that should not be exceeded or maintained, or perhaps even evidence of potentially life-threatening physiological parameters.

How It Might Work
Let’s look at a few examples of how physiological monitoring would work in typical fire service scenarios.

Training
At a department’s burn building, dozens of fire trainees are performing physically intense tasks such as forcible entry, advancing fire lines, victim rescue and building ventilation. Every firefighter participating in the training wears a physiological monitoring garment. They each have a pre-established, customized medical baseline customized (e.g., maximum heart rate of 150, maximum blood pressure of 150/90).

A qualified medical professional (i.e., paramedic) monitors the firefighters. While one group of trainees is inside the burn building, advancing a hoseline up the stairs, one of the firefighters exhibits physiological indicators that place him in the “red” zone specific to his baseline. The paramedic monitoring that firefighter—positioned outside the burn building and monitoring via computer—immediately notifies the IC, who subsequently orders the crew out of the building and the firefighter is placed into rehab. If necessary, the training is stopped all together.

Structure Fire
The 9-1-1 call center receives a call for a fire in a single-family residence with possible victim trapped. As a result, 20–30 firefighters are dispatched from several stations. All on-duty firefighters are already wearing their physiological monitoring garments. Upon arrival, the IC establishes an electronic command post that includes data feeds demonstrating the statuses of all firefighters. Of course, the IC has many duties, so it’s likely that true monitoring will have to wait for later-arriving medical/physiological monitoring personnel.

A truck company crew proceeds to the roof and is cutting a ventilation hole in conjunction with interior operations when a safety officer is alerted to the fact one of the truck company’s firefighters is operating in the red status. At this point, the IC has several options:

  • The crewmember may be in distress or need assistance. An accountability check on that person might be appropriate, or the unit officer should be directed to check on them.
  • The task might be overly physical. The unit officer should consider crewmember rotation. The IC can also consider unit rotation, or assigning additional crews.
  • The crew or crewmember might be ordered to report to EMS or rehab for medical evaluation and monitoring.

The drawbacks to “pulling” crewmembers are clear: When medical monitors begin pulling firefighters out of the fire for personal safety, other firefighters may also have to retreat to assist “at-risk” members ordered to the rehab area, or because they will no longer be able to safely operate interior. This can delay fire attack and other operations. If not skillfully and somewhat judiciously handled, it’s not difficult to imagine fire scenes where firefighters don’t know who is staying or going—creating an even more chaotic and unsafe situation.  

Hazmat Incident
Your hazmat response team is on the scene of an anhydrous ammonia leak at an industrial food storage facility. Several people from the facility are reported missing. A crew of four personnel has already had their pre-entry physicals completed by their physiological monitoring system. All are in a “green status” and are preparing to enter.

The benefits of physiological monitoring in a hazmat situation are significant. In the era after the Tokyo sarin attack, many departments have attempted to address the rescue of viable patients from chemical contaminants. This mindset is contrary to traditional hazmat tactical doctrine: isolate the area and ensure others are not exposed. However, several efforts to establish “quick dress” options have emerged. How can you maintain regulatory requirements without pre-entry medical monitoring?

The answer could lie in real-time continuous physiological monitoring. If you know the baseline health status of the hazmat responder when they arrive on the scene, the additional time and effort to perform this task is reduced, if not eliminated. In essence, it makes every hazmat scene a quick-dress situation.

Medical monitoring during a hazmat situation can also provide the IC with the necessary information to establish a formalized crew cycling process, providing specific information on how many resources are needed in reserve based on the physical demands being placed on crews working.

If you’re wondering whether a cold storage processing facility (or other large building) could pose challenges to the telemetry system signal strength, you’re not alone. Such challenges are being taken into consideration in the development of monitoring and tracking systems.

Rehab
Crews have been working an incident for more than 45 minutes and are being rotated through rehab. A single EMS unit has been as assigned to rehab on this incident, which has 34 personnel operating. This bottleneck leads to undue delays in establishing baseline vital signs, so by the time vital sign measures are established, the 20-minute rehab period has been exceeded. This limits the effectiveness of the rehab operation and also reduces the perceived benefit to the group of responders. The IC is trying to establish a crew rotation with available resources, but it proves difficult based on the bottleneck in rehab.

Physiological monitoring allows the crews rotating into rehab to be monitored for both the “need” for rehab and for the completeness of rehab. It does not remove the EMS component form the rehab process—assessment and history-taking is still needed—but the challenging issue of taking a set of initial rehab vital signs in a timely manner is significantly reduced. In addition, recorded medical data can be tracked via the monitoring devices, which could help with record-keeping and reconstructing cases in which injuries and/or medical events occur.

The need for rehab can be better understood as well. If all four members of a suppression crew are operating in the “yellow” for longer than a prescribed period of time, that gives us an objective basis to assign personnel to rehab, rather than an arbitrary time, which does not account for level of effort. Theoretically, rehab could be directed after an estimation of the number of calories consumed, rather than a set amount of time.

Opportunities & Challenges
The greatest opportunity in physiological monitoring technology lies in its very motivation: to prevent firefighter LODDs. This can be accomplished in several ways:

  • Full-time physiological monitoring will establish baseline fitness levels and deviations from this baseline will identify potential illness.
  • Supra-maximal exertion in responders can be identified in real time, allowing for appropriate intervention and rehab that in turn prevents cardiac emergencies.
  • Real-time cardiac arrhythmias and ectopy can be identified immediately, allowing for appropriate response
  • Personnel can be rotated based on exertion rather than arbitrary time periods.
  • High-stress and hazard situations can be identified. This will allow for improved resource allocations and staffing parameters.
  • Improved awareness and understanding of health parameters can drive improvements of health, wellness and fitness in the responder population.

Eventually, physiological monitoring will be incorporated with other technologies such as accountability, firefighter tracking and PASS alarms; this will further enhance its usefulness.
On the surface, what department wouldn’t want to be first in line for this latest advance in personal protective equipment? When we dig deeper, however, it becomes clear that we need to be prepared for the significant challenges such technology represents, while at the same time preparing our personnel to be open-minded and willing to accept the change.

Cost
Most obvious is the cost factor: Who can afford to field a system that can achieve all of the above goals? Although manufacturers are working hard to make such systems practical and affordable, remember that the cost of integrating any new technology is not just the hardware, but communications and training as well.

Although cost comes first to mind, it may also be the easiest to overcome. Most new technology follows a pattern: When first introduced, it is prohibitively expensive for most departments, but over time it becomes more and more affordable. Think of all the technological “game changers” that have been introduced to the fire service—centrifugal pumps, SCBA, portable radios, thermal imagers, etc.  

Staffing
Throughout history, progress brings unintended consequences. Eli Whitney’s invention of the cotton gin was responsible for a boom in cotton production in the United States, the unintended negative impact of which was the proliferation of slavery to keep pace with the increased demand for cotton. Conversely, as the ability to physiologically monitor individual firefighters becomes reality, how much of an increase in staffing and what level of expertise would be necessary during training or emergency scenarios to adequately monitor each individual firefighter? The fire service must determine how to incorporate physiological monitoring without the need for a huge staffing investment. Work cycles and crewmember rotation will become even more important, as we focus on rotating out members who are nearing the red zone, while taking advantage of those who are still in the green zone who are ready (physiologically) to rotate in. 

One thing is clear: Medical monitoring does require dedicated personnel. Expecting personnel assigned to other areas to absorb monitoring as an addition to their current responsibilities fast becomes a slippery slope, especially if the RIT or medics are forced to abandon their monitor posts to perform their primary duties.

Determining what qualifies as an emergency
Physiological monitoring will also need to prove its reliability before we can expect widespread acceptance. Do the physiological parameters provide an accurate picture of illness compared to the to the perception illness? In other words, does a “red light” status equal real distress in a responder?

Related to this, is monitoring as simple as having just any firefighter stare at a computer screen and alert the safety officer that a firefighter’s pulse rate exceeded their target heart rate by 10%? Or, is there a duty to have an adequately trained paramedic or medical professional capable of identifying emergent health danger signs, but not so overzealous as to disrupt training and operations because someone took one too many breaths?

The legal maxim “hard cases make bad law” has some relevance here. It’s fair to say that unless a reasonable balance between safety and practicality is identified (and supported by a jurisdiction’s legal counsel), an over-abundance of health/safety alerts may be ignored for individual firefighters, similarly to a chronically malfunctioning fire alarm.

Take, for example, a training evolution where several dozen firefighters are working hard, practicing advancing hoselines and roof ventilation. These activities elicit significant physical activity, especially at the height of each task. During such evolutions, any number of firefighters may naturally drift into the “red,” or alert, status, and according to procedure, should be relieved of duty until coming back down into a “green” or acceptable physiological range.

Assume that the medical monitor stopped the training evolution the first few times the limits are exceeded. As firefighters naturally become more fatigued during this arduous training, it’s not hard to imagine increasingly frequent drill stops/starts with the medical monitor beginning to feel a little like the boy who cried wolf. After a while, the medical monitor may feel pressured or become complacent, “ignoring” the system alarms because nothing “bad” has happened thus far, and also sense a growing pressure from drill participants to use “good judgment”, a.k.a., quit bothering us with the procedural alarms, and only stop the drill when a “serious” alarm comes through.

A medical monitor at emergency incidents would likely feel even more pressure to less stringently monitor firefighters; they might rationalize that “I let the firefighter continue working because we almost had the fire out, which saved even more lives.” This respective logic could serve as an excuse as to why the monitor failed to pull someone off of a job who was exhibiting warning signs/symptoms according to the physiological monitoring system. 

Many other challenging, but realistic situations can be hypothesized that run counter to the purpose of physiological monitoring, whether during training or exercises.

Culture
Perhaps the biggest sticking point to physiological monitoring is the culture of the fire service itself. Can technology override the noble and heroic motivations of a responder? How do you disqualify a responder, and in turn the whole unit, while rescue operations are ongoing?

Privacy will also be a concern. Firefighters may regard monitoring as another instance of “big brother”; labor unions may argue that such technology creates the potential for discrimination, or endangers firefighter jobs. Firefighters could even try to subvert the system to avoid being reassigned or required to undergo medical care.

The goal of physiological monitoring is simple: to prevent firefighter injuries and LODDs from heart attacks and strokes. But departments should be prepared for the challenges and potential pitfalls of knowing what they previously did not, and could not, know prior to the advent of personalized physiological monitoring technology.  

A Final Word
Physiological monitoring is coming to an incident command post near you soon. There are still several hurdles in the way, but several of the best and brightest fire service leaders are interacting with exercise scientists and bioengineers to see it to reality. When it does, we must be ready to integrate it into our operations. And that requires thinking through how it will affect every facet of the fire service, from legal issues to training to incident response. To the men and women on the front line, whose very lives hang in the balance, we owe nothing less.

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The wireless pulse oximeter is a component of an integrated system developed by researchers in WPI’s Precision Personnel Location (PPL) team--technology that is designed to locate and track firefighters inside buildings, and to also continuously monitor their vital signs. Photo courtesy WPI
This image shows a proposed Incident Commander Display screen showing the location and tracks of the firefighters inside a building along with their physiological information. The firefighter icons are green, yellow, or red. Red indicates a firefighter is in potential trouble due to vital signs being outside acceptable limits or due to non-movement of the firefighter. Some of the physiological information being displayed is the heart rate, respiration rate, skin temperature, and oxygen saturation level. Photo courtesy WPI
Worcester Polytechnic Institute (WPI) electrical and computer engineering graduate student David Hubelbank tests a wireless pulse oximeter designed to monitor blood oxygen saturation, pulse, respiration rate, and skin temperature while the wearer is engaged in strenuous physical activity. The current prototype is held against the forehead by a strap, but may ultimately be integrated into the firefighter’s helmet. Photo courtesy WPI


Implementing Physiological Monitoring in the Fire Service

How will physiological monitoring systems affect command decision-making?
The wireless pulse oximeter is a component of an integrated system developed by researchers in WPI’s Precision Personnel Location (PPL) team--technology that is designed to locate and track firefighters inside buildings, and to also continuously monitor their vital signs. Photo courtesy WPI


This image shows a proposed Incident Commander Display screen showing the location and tracks of the firefighters inside a building along with their physiological information. The firefighter icons are green, yellow, or red. Red indicates a firefighter is in potential trouble due to vital signs being outside acceptable limits or due to non-movement of the firefighter. Some of the physiological information being displayed is the heart rate, respiration rate, skin temperature, and oxygen saturation level. Photo courtesy WPI


Worcester Polytechnic Institute (WPI) electrical and computer engineering graduate student David Hubelbank tests a wireless pulse oximeter designed to monitor blood oxygen saturation, pulse, respiration rate, and skin temperature while the wearer is engaged in strenuous physical activity. The current prototype is held against the forehead by a strap, but may ultimately be integrated into the firefighter’s helmet. Photo courtesy WPI

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