Human performance under extreme stress: The EMS connection

How to best manage our high-stress, time-compressed working conditions to control fight-or-flight response


The call comes in at 0130. Tones drop and give that oh-so-familiar sledgehammer-to-chest feeling. Motor vehicle crash, driver trapped.

As you attempt to get out of bed and don your footwear, you struggle to remember the location. The early morning mental fog has set in, and the details are slipping from the forefront of your mind as quickly as you place them there.

On arrival, the driver’s head is visible outside the shattered driver’s door window glass. The patient was partially ejected when the vehicle rolled. No seatbelt, lots of blood, not conscious, barely breathing.

Stress is the relationship between three elements: perceived demand, perceived ability to cope, and the perception of the importance of being able to cope with the demand.
Stress is the relationship between three elements: perceived demand, perceived ability to cope, and the perception of the importance of being able to cope with the demand. (Photo/Marc Vasconcellos, The Enterprise)

The scene is dark. No auxiliary lighting has not been set up yet. Only the asynchronous red and white LED flashes from our own vehicles let our eyes see the situation before us. The vehicle is on its top, and light smoke is coming from the engine compartment. The driver is laying face down on the pavement with head and shoulders visible out the window, but their foot is wrapped up in the break pedal, making extrication necessary.

The driver is finally freed and moved into my ambulance. The overhead lights show the horrific nature of the injuries. The patient is struggling to breathe with so much blood blocking the airway. I try to move their jaw to open the mouth, but it feels unnatural and moves in many directions at once, obviously broken. I ask for suction, but I don’t know who is there with me. No response so I ask again.

Off to my left I see the entire airway kit being dumped out in a frenzied search for the item.

I am having difficulty focusing on anything but the patient in front of me. When I finally find the suction unit, I repeatedly drop the wrapped catheter and tubing attempting to assemble the system. This is taking too much time. I have to intubate this person!

The real world disconnect

In my years of educating paramedic students in the nuances of airway management, certain themes tend to appear in their questioning: “What do I do if …? What happens when …? What if the patient has …?”

While perfectly sound logic and quite normal to explore scenarios that cause concern, what troubles me is the commonality of the descriptions of their clinical and field experience in terms of airway emergencies. The students often described the actions of a skilled provider using terms such as “a difficult airway” or “really tough tube.”

I began to wonder, are most field intubations difficult? This seems unlikely even with difficulties attributed to work in unimproved locations. Is something else going on here? Why would so many practitioners describe similar events?

I believe it all comes back to how we manage our stress response.

What is the normal response to stress?

An explanation applicable to emergency services posits that stress is the relationship between three elements: perceived demand, perceived ability to cope, and the perception of the importance of being able to cope with the demand. In other words, what is my assignment, can I handle this, what happens if I don’t handle this. This definition does not explain how the body will adjust accomplish a task. For this we must dive into the physiologic, starting with the endocrine system.

When the brain reacts to a stimulus, it sends signals to various glands to secrete hormones. These hormones cause the body to react in ways that are either advantageous to accomplishing a task or improving chances of survival. One such gland is the adrenal gland, which is the home of adrenaline. Another name for this hormone is epinephrine, and if you have ever taken ACLS, you know what it will do to the heart and blood vessels.

Here’s a simple example to explain the operation of the system: I am walking in the woods and a bear jumps out in front of me. My brain recognizes a threat and sends a signal to the adrenal gland to release adrenaline. The result is pumping nutrient- and oxygen-rich blood to large muscle groups, so I can either run away or prepare to repel an attack. This is also known as a fight-or-flight response. It should be noted that not all hormonal signals are to run or fight. Others cause changes in the brain that improve attention, focus and fine motor skill. These are useful in performing well on a math test or tying a series of knots.

The Evaluative Reflex is what the brain uses to determine what system should be activated. Is it time to work or is there a threat to my survival? In the NASA report “Stress, Cognition, and Human Performance: A Literature Review and Conceptual Framework,” Mark Stall concludes “that humans are spring-loaded to evaluate the environment and that this evaluation likely takes place subcortically, prior to any conscious awareness of emotion or higher-order cognition occurring.” This is a big deal. If our brain is functioning at a level before our conscious thought, then the environment we operate in will play a huge role in the outcome or our responses.

What are our working conditions?

Our profession is unique. We venture into non-secured and unimproved locations immediately after the normal order is broken. Buildings are not supposed to collapse, nor houses burn. Vehicles and aircraft are not supposed to crash. People are not supposed to be swept away in flood water, nor should winds uproot trees. We all know that these things do in fact happen – and serve as a key reason we have jobs. Bad things happen, and we are hard-wired to go put the world back together again.

We perform very technical work under time constraints. Most of the skills used in EMS require hand-eye coordination, tactile sense and spatial awareness. We would not use the same amount of physical effort to start an IV line as we would to force open a door of a vehicle. Our brains have learned to anticipate how much effort each skill will require and to incorporate a large amount of concentration to the completion of tasks. High-order functioning is used in problem-solving. Drug dose calculations, interpretation of vital signs and ECG information all demand a generous portion of the brain’s ability. We devote immense amounts of energy to facilitating this level of concentration, as we know the gravity of the result. The consequence of improperly administering a medication can be severe. Misinterpreting information or misdiagnosing a patient can be lethal.

What happens when our brain activates the wrong system?

Let’s turn back to the evaluative reflex. The brain is assessing threat recognition at a subconscious level. The primary stressor in our line of work is emotional. The mind wants to accomplish a task, perceives we can cope, and understands the importance of the task.

We begin to have a problem when the plan doesn’t match our perceived notion of how this should work. Further complicating matters is a subconscious response to a perceived environmental threat. If we see a mangled human, somewhere in our primitive mind is a belief that we, somehow, will also be mangled. Further, if the brain is reacting to a threat, it will do so by activation of the adrenal gland to give you the ability to run or fight. Big muscle groups are now in play, fine motor control is degraded, and vision narrows to focus on the threat. This has been referred to as tunnel vision.

To bring it all together, the nature of the environment we work in, if left unchecked, will cause your brain to react to the same threat that placed your patient into harm’s way. This is not a rational read, one that occurs in a lower-functioning level of thought of which you most likely are not aware. Further, the brain will focus on the issue causing the stress/threat, resulting in tunnel vision.

Attempting to fight through it, forcing your brain to function in a higher capacity is difficult, if not impossible. When big muscle groups are engaged, fine motor control is vastly reduced. Haven’t you ever wondered why the back of an ambulance looks like a mess after a serious run? Have you ever observed a partner respond to a request for a piece of equipment or dose of medication with dropping the item, throwing it or having difficulty with packaging that, at any other time, would be no problem at all?

How to manage stressful situations

There are several strategies we can employ to manage high-stress situations.

If the cause of the issue is a perceived loss of control of the environment in the face of a threat, then that answer is straightforward. We train. In EMS, we train on a multitude of subjects but often in a manner that allows us to either check a box as a requirement or finish simply “to say we did it.” This does us and our patients a great disservice.

Conduct realistic training: Stress inoculation is a concept that hypothesizes that the negative response to stressful situations can be mitigated through repeated, albeit small, exposures to the stressful event. Two things need to be identified for this to work:

  1. The provider being trained must be anticipated to perform in a threatening environment.
  2. The environmental condition should be replicated as much as possible. By creating a realistic simulation of a stressful event, the brain begins to gain experience with resolution of the event.

With experience, the provider develops coping strategies to solve the problem. These experiences, in turn, develop a mental map for the brain to follow. If effective, the subconscious will no longer deem the situation a threat.

Translated for emergency services: Train like we fight. While high-fidelity simulation is the gold standard of stress inoculation, it is also cost-prohibitive. However, we can use the tool we have been given as children, our mind’s ability to imagine. No, I am not asking you to play pretend, but I am pointing out the simple fact that your brain will use your past experiences to fill in gaps when environmental information is not available. It is the same reason that kids are afraid of the dark and haunted houses are scary.

With that in mind, I propose the following: Reduce visual input when training, and substitute audio input. Try performing common skills in the dark, or with a simple head lamp. Add in audio of radio traffic or common sounds from a working scene. These simple actions trick the brain into feeling similar threats we would experience in real life while ensuring a reduced risk environment. Stress inoculation can still be performed with some ingenuity and creativity of the trainer.

Remember the key to this method of training is to provide enough realistic experiences that the mind does not deem the situation a threat. Educators should plan training events to consist of several evolutions to provide enough experiences for a mental map to be created. The map will allow the mind to follow a script of actions to follow. To simplify, following a mental script of action reduces stress by limiting unknown variables to a situation. More mental capacity can therefore be utilized for higher-level functioning.

Help your teammates: A second action we can take is to watch out for our teammates. Due to our varying experience levels, plus outside life stressors, providers on the same scene will show differing reactions. Be aware of this, be patient, be calm, and provide tasks that are easily performed. There should be no shame in asking for help or offering a respite. We all have been there, and if you haven’t, just wait; it’s coming to a scene when you least expect it. Further, the nature of our work is quite extraordinary. Understand that, at times, your environment may overwhelm what your mind was designed to handle.

These issues can be mitigated by putting in time and effort in the form of realistic training evolutions. Allowing your brain the ability to develop a mental script for operating in unknown environments not only builds confidence, it also changes the way your brain and endocrine system will respond to perceived threats. Further, the chance of successful outcome to operational goals can be increased if team members plan for the physiological limitations of human cognition under stress. We can anticipate these issues during training evolutions and work a process for stress-management into our response plan.

Note: I would like to thank Mark Staal whose work at NASA, including “Stress, Cognition, and Human Performance,” was essential to my understanding of this topic.


Read next:

Read next:

The most effective ways to combat stress

Comparing stress levels and coping mechanisms, from alcohol to exercise and peer support in first responders


About the author

Michael Montgomery is a 20-year veteran of a central Ohio fire department where he serves as a firefighter/paramedic and the organization’s head of community paramedicine. He holds numerous technical certifications, including EMS Educator, Public Safety Diver, Rope Rescue Technician and Swift Water Rescue Technician. He is also trained as an IAFF peer supporter, with training in crisis intervention teams (CIT) and critical stress incident management with law enforcement. Montgomery is licensed as a registered nurse with over 15 years of experience in orthopedics, emergency and flight.

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