How well do you perform when the pressure is high? This is one of my favorite emergency medicine topics. Emergency personnel pride themselves on thriving under pressure. Doctors like to think of themselves as perfect, maybe even god-like. Combine the two, and you can imagine the ego of the average emergency physician. But underneath all that bravado, we are all human. We all experience stress, and we all respond to stress in distinctly human ways.
I like talking about performance under pressure precisely because we don’t talk about it. Because if stress is mentioned in an emergency medicine context, it is to say that we should “just handle it and get on with our jobs”. Because we all experience stress – pretty extreme stress – and yet it wasn’t mentioned once in my medical school or residency training.
We send people out into the wild just expecting them to cope. For the most part, we do cope. Some people develop great coping strategies. Unfortunately, others use maladaptive strategies, or don’t learn to cope at all, until it’s too late.
What follows are my relatively extensive notes on stress, how it affects us, and the various ways we might be able to effectively manage stress to ensure that we are performing at the extremely high level demanded of us.
What is stress?
This is a surprisingly difficult question to answer. There are many competing definitions of stress in the literature without a clear winner. (Driskell and Salas 2013) However, although a precise definition might be helpful for research, for emergency medicine I think the definition is less important. Emergency clinicians know exactly what stress is, even if we can’t specifically define it.
There is a general sense that stress is always bad, but as we will discover as we work through the literature, it doesn’t have to be. The stress response is an important physiologic phenomenon. Emotions are rarely just good or bad. We often consider fear to be inherently negative, but we need fear to help us avoid potentially dangerous situations. Happiness is considered inherently positive, but if we were happy all the time, we would never accomplish anything new. Stress is similar. Without a stress response our responses to emergencies would be lackadaisical and ineffective. Emotions are neither inherently harmful nor beneficial. Emotions become harmful when they are the wrong intensity, for the wrong duration, occur with the wrong frequency, or are the wrong type for a particular situation. (Gross 2015)
There are two types of stressors we that will commonly be faced with. Primary stressors are those which arise from the demands on the task in front of us, such as the blood obscuring our view of the airway. Secondary stressors are aspects of the situation that are unrelated to the challenge itself, like being afraid of failure, wanting to perform well in front of others, or generally feeling ill prepared. Primary stressors can help you step up your arousal to meet the challenge in front of you. Secondary stressors are more likely to impair performance because they are unpredictable, harder to control, and unrelated to the task at hand. (Whitelock and Asken 2012)
Stress is a transactional state. It is neither something external to you, nor a purely internal response. It is the result of the interaction between the individual and their environment. (Meichenbaum 1985) This is an essential concept, because it is the transactional nature of stress that makes the various cognitive techniques discussed below effective.
When coping with stress, we can break our responses in to two broad categories. Problem focused coping aims to manage negative emotions by addressing the underlying problem. Emotion focused coping aims to manage emotions directly without addressing the underlying problem. (Driskell and Salas 2013; LeBlanc 2009) Problem based coping strategies are ideal in controllable situations, whereas emotional based strategies are useful when stressors are brief and uncontrollable. To perform optimally under pressure, you will ideally be able to draw on both problem focused and emotion focused coping techniques.
The threat challenge assessment
Before we get into the various physiologic and psychologic effects of stress, it is important to note that an individual’s response to stress is heavily influenced by the person’s assessment of the situation. (Kowalski-Trakofler et al 2003; Driskell and Salas 2013) First, we assess the demands of the situation: what is required of us to achieve a goal. Next, we assess the resources, personal and environmental, that we have to achieve that goal. When resources are sufficient to deal with the demand, we frame the situation as a challenge, and a positive psychologic state of “eustress” ensues that supports optimal performance. When demands outweigh resources, we see a threat, and a negative psychologic state of “distress” results than can impair performance. This response is subjective and primary based on the individual’s perception of the demands and resources. Any factor that increases perceived demands or decreases perceived resources increases the likelihood of a distress response. (Weisinger and Pawliw-Fry 2015; LeBlanc 2009)
How does stress affect us?
There are a number of different physical manifestations of acute stress. We have all experienced the sweaty palms, rapid heart rate, and GI upset that can accompany stressful scenarios like oral exams or job interviews. At higher stress levels, tunnel vision can occur, potentially leading to decreased situational awareness and missed information. (Whitelock and Asken 2012; Grossman and Christensen 2004) Auditory exclusion or “tunnel hearing” can impair communication. (Whitelock and Asken 2012; Grossman and Christensen 2004) Perceptions of time can either speed up or slow down. (Whitelock and Asken 2012) Peripheral vasoconstriction results in impaired fine motor control and tremors can develop as the result of high sympathomimetic tone. (Grossman and Christensen 2004)
Of course, acute stress reactions are complex and occur in a myriad of situations. In a survey of police officers who had been involved in gunfights, 85% reported diminished hearing or auditory exclusion, but 16% reported sounds being intensified. (It adds to more than 100% because some officers experienced both at different times during the encounter.) Likewise, although 65% of officers experience time as slowing down, 16% experienced it as sped up. (Christensen 1997) The variety of possible responses make it hard to predict the response that any one individual will have in a given stressful situation. Likewise, it is difficult to extrapolate studies of stress from other fields into the realm of medicine.
The physiologic response to stress seems to be, at least in part, modulated by the threat-challenge assessment. A challenge state is associated with improved cardiac efficiency, dilation of peripheral vasculature, and low cortisol levels. A threat assessment, on the other hand, is associated with peripheral vasoconstriction, diminished cardiac output, and elevated cortisol levels. (Jamieson, Mendes, and Nock 2013)
The ways in which our thinking changes under stress are probably even more important in emergency medicine. There are four major steps at which stress can impair behaviour: it can impair perception of the problem, analysis of the problem, decision making, and motor action. (Whitelock and Asken 2012)
We all know about the “fight or flight response”, but there is actually a third common response to stress: freezing. (Whitelock and Asken 2012) Impaired concentration and slowed decision time are common under stress. (Whitelock and Asken 2012; LeBlanc 2009; Petrosoniak and Hicks 2013) Stress can also lead to more impulsive behaviours, resulting in “rescue fever”, where rescuers rush into unstable or unsafe scenarios. (Whitelock and Asken 2012)
Acute stress can result in a loss of situational awareness. (Petrosoniak and Hicks 2013; Driskell and Salas 2013) For this reason, among numerous others, stress has also been demonstrated to impair team performance. (Petrosoniak and Hicks 2013; LeBlanc 2009)
Selective attention is important mental process in the chaos of the resuscitation room. It is the process that allows us to focus on a single object, and to exclude others from our attention. Under pressure, attention is naturally focused on the locus of stress. Therefore, if the stress is intrinsic to the task being performed, attention will be focused on the problem at hand, and performance shouldn’t be adversely affected. However, if the stressors are external, such as loud noises, a screaming family, or disruptive team members, attention will be drawn away from the task at hand, and performance is likely to suffer. (LeBlanc 2009) Similarly, performance on divided attention tasks, or those that require integration of information from several sources (such as complicated medical resuscitation) generally suffers under pressure. (LeBlanc 2009)
Stress has a variety of impacts on memory. (Petrosoniak and Hicks 2013; Grossman and Christensen 2004) Working memory seems to be impaired in the context of a threat assessment, whereas a challenge assessment results in no impairment. (LeBlanc 2009) With regards to forming new memories, stress can either impair or enhance the process. When the stressor is directly related to the memory, memory improves. However, if the stressor is something peripheral to the thing to be remembered, memory seems to be impaired. (LeBlanc 2009) In terms of memory retrieval, stress is an impairment, but that impairment seems to be limited to individuals who assess the situation as a threat as opposed to a challenge. (LeBlanc 2009) Furthermore, stress has less of an impact on memory retrieval in individuals with a great deal of experience. (Driskell and Salas 2013)
The impacts of stress on decision making are somewhat complex, and I will explore them in a little more detail below. Generally, stress results in a greater reliance on heuristics and a reduced ability to analyze complex situations, with more classic errors in reasoning. (Petrosoniak and Hicks 2013; LeBlanc 2009; Driskell and Salas 2013) Decisions made under stress tend to favour lower risk or “more certain” options. (Driskell and Salas 2013) Stress can also result in tactical fixation: the failure to change strategy when needed. (Whitelock and Asken 2012; Driskell and Salas 2013)
One might ask whether these stress responses are only observed in the psychology lab, or whether they have impact in the real world. (On the other hand, if you have experienced extreme stress, that might seem like a silly question.) Grossman’s “On Combat” is full of real stories from soldiers and police officers that illustrate the occurrence of all of the above physiologic and psychological changes in real people under extreme stress. (Grossman and Christensen 2004) It is even commonly reported that, under extreme stress, people are physically incapable of the relatively simple task of dialing “911”. (Grossman and Christensen 2004) Although stress responses are variable and complex, I don’t think that there is any doubt that they play an important role in real world performance under pressure.
Stress in medicine
I am not aware of any study categorizing the impacts of stress during live medical resuscitation. However, speaking with colleagues, it is clear that many of us have experienced phenomena similar to those reported by soldiers and police officers. Personally, I have experienced a degree of tunnel vision while performing time-sensitive procedures on dying patients. I have experienced auditory exclusion: not hearing the handover from paramedics because I was too focused on the scene in front of me. I have had trouble remembering the details of a horrible pediatric resuscitation as I tried to chart later. The study might not exist, but I think it’s clear that these stress responses are a daily occurrence in resuscitation rooms.
The Siddle and Grossman classification
The classification of physiologic responses to stress based on heart rate by Siddle and Grossman is frequently reproduced. (Grossman and Christensen 2004) The classification of various responses based on a specific heart rate is likely inaccurate, a point that Grossman specifically emphasizes. An individual’s heart rate and response to stress can vary significantly based training, physical fitness, and a variety of other factors. (Grossman and Christensen 2004) However, I think the schema is still helpful as an overview of the various physiologic responses to stress:
The key here is not the specifics about heart rate, but that our physiologic responses to stress follow a fairly consistent and predictable pattern. As stress increases, you first enter a phase of increased alertness and concentration. As stress mounts, fine motor skills, complex motor skills and reaction time improve, plateau, and then deteriorate. Fine motor skills will deteriorate before complex motor skills, which will, in turn, deteriorate before perceptual changes like tunnel vision, decreased hearing, and distorted time perception begin. (Grossman and Christensen 2004) We all experience some version of these physiologic changes. Have you ever had trouble writing legible notes after a particularly hectic resuscitation? That is probably the result of the peripheral vasoconstriction and catecholamine release that consistently degrades fine motor skill under pressure.
The ideal zone of performance will be different for different activities. Grossman is discussing military and police performance, where performance requires more gross motor skills, and suggests “condition red” is the optimal zone of performance. In medicine, with a higher reliance on fine motor skills, we might be be better in condition yellow. Grossman also emphasizes that, with training, you can expand the zones, meaning you should be able to tolerate higher levels of stress before performance diminishes. (Grossman and Christensen 2004)
For a little more on Grossman’s book, you can turn to EMCrit episode 118: EMCrit book club – On Combat by David Grossman
Performance under pressure
The research on how we perform under pressure is somewhat mixed. Some studies indicate impaired performance under pressure. (LeBlanc et al. 2005; Cumming and Harris 2001) Other have demonstrated improved performance. (LeBlanc et al. 2005; LeBlanc et al. 2008)
The Yerkes Dodson law suggests that for any activity there is an optimal level of arousal for peak performance. The common illustration is a simple curve that demonstrates that performance suffers both in states of high and low arousal. However, the original Yerkes Dodson data divided tasks into two groups, and for simple tasks like focused attention, there did not seem to be a significant drop off of performance at higher levels of arousal. (Diamond et al. 2007) The goal of training is to change the shape of this curve, such that optimal performance can be achieved over a wider range of conditions.
The exact mechanisms through which stressors result in changes in performance are debated. Clearly, there are some physiologic and hormonal changes at play. Stressors may also act as distractions that limit one’s available attention. (J. E. Driskell, Johnston, and Salas 2001) Another factor that determines one’s ability to deal with stress is prior experience with stress (this is one of the key tenets of stress inoculation therapy, discussed below). (Meicheribaum and Novaco 1985)
You can read more about this topic in Mike Lauria’s post “The Tao of Resuscitation Performance”
Thinking under pressure
Daniel Kahneman has popularized the concept of system 1 and system 2 thinking. System 1 represents intuitive, unconscious reasoning that relies on heuristics or mental shortcuts. It is quick and requires minimal effort. Consequently, it is the process used most frequently. However, because of its reliance on heuristics, system 1 is prone to bias and cognitive errors. System 2, on the other hand, represents conscious, analytic thought. It is slow, deliberative, and requires significant effort. It is generally thought to be less prone to errors. (Kahneman 2011)
In high pressure, critical situations, system 2 is likely to fail. System 2 is slow – slow to accept changing reality and slow to act. (Grossman and Christensen 2004) We know that we rely more heavily on heuristics under pressure. (LeBlanc 2009) This is often thought of as weakness, but it’s not clear that system 1 thinking is necessarily a weakness when employed by experts, especially in time critical scenarios. Intuition is one of our most powerful tools in a crisis. (LeBlanc 2009; Grossman and Christensen 2004)
Decision making definitely changes under pressure, but it is less clear if those changes degrade performance. The decisions made are generally simpler, but are often rational and make important use of experience. (Driskell and Salas 2013) In a classic laboratory experiment, subjects were required to run a computer simulated forest fire management task. Half of the subjects were placed under an external stress (loud noise). The problem solving strategies differed significantly between the groups, with the unstressed group relying on in-depth analytical analysis and the stressed group focusing only on the general outline of the problem. However, despite the differences in approach and different types of errors made, both groups performed the task equally well. (Dörner and Pfeifer 1993)
Under time pressure, people tend to adopt simpler forms of information processing, in which alternatives are not fully formed, and certain important cues or patterns are used to rapidly make a decision. In other words, people narrow their field of attention under stress. (Kowalski-Trakofler et al 2003) If this narrowing of attention results in important information being missed, performance would suffer. However, if the narrowing of attention allows the individual to ignore nonessential information and focus on only the most important cues, this could be an effective and efficient cognitive strategy. (Kowalski-Trakofler et al 2003) Furthermore, even if the decision making is technically inferior, it makes little sense to use a time consuming analytical strategy when faced with severe time pressure. (Driskell and Salas 2013)
A number of alternative decision strategies have been described in stressful scenarios. A lexicographic strategy simply looks at a single important dimension of the choice and picks the option with the best rating in that dimension. An elimination by aspects strategy involves evaluating all options on the most important dimension and rejecting options that fail to meet the desired criterion. The remaining options are then evaluated on the next most important dimension, until only one option remains. (Driskell and Salas 2013) Although these strategies are not the ideal logical strategy, they are quick, efficient, and may be good enough, when employed by experts, for the type of rapid decisions that are necessary in emergencies. Interestingly, the closer together two options are, the less important the decision making becomes. In other words, when there is a clear winner, the choice is often obvious, but when two choices are very similar, the outcome may not be significantly affected, and therefore the decision becomes less important. The ambiguity of the data in emergent scenarios may outweigh the advantages of any one option. (Driskell and Salas 2013)
Recognizing that the decision making done in complex, real world scenarios is different from that performed in psychology laboratories, naturalistic decision making is a theory based on empiric observation of real world experts decisions. (Driskell and Salas 2013) Recognition-primed decision making is one of the models that developed out of this research. Recognition-primed involves rapid pattern matching, followed by a brief mental simulation to determine if the initial option is a reasonable solution in this scenario. (Klein 2008) You can read more about naturalistic decision making on the International Clinician Educators blog.
There is a very large body of research that addresses decision making under stress, but the vast majority of these studies were performed in highly controlled psychology laboratories. How applicable these are to real world settings in general, and medical resuscitation in particular, is an open question. (Kowalski-Trakofler et al 2003) The case studies that examine decision making in real world crises generally conclude that decision making deteriorates under stress, but these conclusions must be tempered by the fact that information is often incomplete and even incorrect in times of crisis, which would make perfect decision making essentially impossible. (Driskell and Salas 2013)
All the research on decision making under stress is subject to significant assumptions. Either you examine the decision making itself and make assumptions about the best kind of decision making, or you examine outcomes. The problem with examining the decision making strategy itself is that there is considerable debate about the ideal decisions strategies. It isn’t clear that system 2 thinking is really better than system 1, especially in emergencies. The problem with examining outcomes is that decisions are not perfectly correlated with outcomes. Good decisions, for a variety of reasons, can still result in bad outcomes and vice versa (resulting in hindsight bias).
For now, I think the best we can do is acknowledge that decision making patterns change under stress. It is probably not appropriate to try to force slow, methodological type 2 thinking on fast paced medical resuscitations, but recognizing our reliance on heuristics, we might want to build in checklists or cognitive stop points that allow us to think about our thinking, when there is time.
For more about decision making in the resuscitation room, make sure to review Scott Weingart’s talk on OODA loops.
The optimal zone or “flow”
Watch any sport long enough and you will inevitably hear about an athlete who is “in the zone”. If you have worked in emergency medicine long enough, I am sure you have a sense of what this means. You are running a resuscitation and everything just clicks. Your thinking is perfectly clear, time appears to slow down, everything is working, and the job just seems fun.
For any activity, there is a balance between your skill, resources and the demands being placed on you. If the demands outstrip resources, we see anxiety and poor performance. When skill or confidence significantly outstrip demands, we see boredom that could also degrade performance. Somewhere in between, there is a zone that leads to optimal performance. The level of difficulty is high enough that it demands your entire attention, but not so high that is begins to impair your cognitive abilities. Performance in this Goldilocks zone is often referred to as being in a “flow state”. (Whitelock and Asken 2012; Herzog and Deuster 2014)
In emergency medicine, we generally aren’t worried about low challenge states (although it is important to have cognitive tools to harness your quasi-ADHD as you drift into the boredom area of this graph). In general, when we are talking about performance, we are talking about extremely challenging situations. Looking at the graph gives us some hints as to how to handle this. We can and should focus on ensuring we are as skilled as possible. The degree of challenge seems like it would be out of our control, but in fact, it is our subjective interpretation of the challenge that really matters. We can learn cognitive tools that help regulate our sense of challenge, and therefore bring ourselves back into “the zone”. (Herzog and Deuster 2014)
You can hear more about flow from one of the real experts, Chris Hicks, in his SMACC talk “Into the Deep – Pushing the limits of human performance for resuscitation teams”.
The concept of “flow” was originally described by Mihaly Csikszentmihalyi. You can watch his TED talk on the topic below:
Impaired performance in stressful, high-acuity scenarios has been reported in medical students, paramedics, and staff surgeons. (LeBlanc et al. 2005; Leblanc et al. 2012; Piquette et al. 2014; Harvey et al. 2011; Arora et al. 2010; Krage et al. 2014) For example, in one study, emergency medicine and surgery residents were evaluated in both a high stress and a low stress trauma simulation. In the high stress scenario the patient was sicker, was a young pregnant female (for emotional stress), involved a compatriot paramedic who questioned the residents’ decisions, and had higher ambient noise levels. Cortisol levels were measured and were higher in the high stress scenario, indicating physiologic differences. Scores of resident performance, using a previously validated score, were lower in the high stress scenario. This is a believable study that demonstrates impaired performance in a stressful scenario, but there are significant limitations: it takes place in a simulated environment and studies learners rather than experts. (Harvey et al. 2011) In other studies, performance was not seen to deteriorate despite higher reported stress levels. (LeBlanc and Bandiera 2007; Bjørshol et al. 2011) With regards to how stress impacts the performance of expert clinicians in the resuscitation room, the evidence simply doesn’t provide us with a good answer.
Emergency medicine is an inherently stressful pursuit. In other professions, the optimal approach might be to redesign activities to minimize stress, thus maximizing performance. To the extent that we can manage stressors, such as ensuring the correct equipment is always available and trying to manage bed block, we absolutely should, but for the most part, we will never be able to separate emergency medicine from intense performance pressure. Therefore, we need strategies to help us manage stress and ensure that we can perform optimally under pressure.
Watching our peers perform at incredibly high levels under stress, it can seem like some people are just naturals. It is easy to get the impression that these individuals simply have some skill that you don’t. Although we may have different starting points, stress management – like all other skills – can be learned. You can get better. (If you have never read Mindset by Carol Dweck
Before the stressor: Stress preparation
High level musicians and athletes have been using stress preparation techniques with great success for a long time. However, it is obvious that these techniques don’t stand alone. Michael Jordan doesn’t sink a free throw just because of his breathing technique. First, he learned the proper shooting technique, then practiced it thousands of times. But with a game on the line, breathing was one component of ensuring that he was able to manage stress and reproduce the shooting technique he had spent his life perfecting. Similarly, these stress management techniques will not make you a great resuscitationist. You must first master the craft; put in your time practicing. These techniques are to ensure that you are able to perform at the very high level you are capable of, even in the worst situations.
Much like you have to practice your technical skills, the skills discussed here also require practice. You can’t expect to step into a horrible resuscitation and use tactical breathing or centering techniques for the first time. They just won’t work for you. They require practice so they will be available to you when you need them.
It is essential to prepare your tools. Much like a mechanic must take time to keep his tools in optimal shape, so must medical personnel maintain their key tools: their minds and bodies. Exercise and adequate sleep are essential. (Grossman and Christensen 2004) Trying to address personal stressors like relationship issues before coming to work is difficult but important. Similarly, we must be aware of the effects of substance use, whether alcohol, caffeine, or drugs, on our overall health and performance. (Whitelock and Asken 2012)
Stress inoculation training (aka stress exposure training)
Stress inoculation is a form of cognitive behavioural therapy that involves three steps. The first step is education or cognitive preparation, focusing on understanding the physiologic and psychological impacts of stress. The second step is skill acquisition and rehearsal, focusing on developing and practicing arousal control or stress reduction techniques. The skills learned are cognitive restructuring techniques aimed at controlling negative thoughts and relaxation techniques aimed at increasing control over the physiologic responses to stress. (Both problem based and emotion based coping mechanisms). The final phase is application of these skills in real world or simulated environments, with reflection and feedback. (Petrosoniak and Hicks 2013; Meicheribaum and Novaco 1985; Whitelock and Asken 2012; LeBlanc 2009; Saunders et al. 1996)
Although there are numerous well described stress reduction techniques (described further below), one point that is frequently emphasized in stress inoculation therapy is the need to draw on personal experience and expertise. (Meicheribaum and Novaco 1985; Meichenbaum 1985) The idea is to think through one’s most stressful encounters and consider the things that one did or could have done to manage the stress. In emergency medicine, we have the tremendous benefit of colleagues with a wealth of experience in managing stress. I would also try to draw on their expertise. Furthermore, no single coping strategy is universally effective. The object of stress inoculation training is to equip individuals with a variety of coping strategies that can be mixed and matched. (Meichenbaum 1985)
It should also be emphasized that learning to manage stress is a separate task from learning the skills of resuscitation. In can be confusing and counterproductive to introduce stress into sessions where clinical skills are supposed to be learned. Remember, stress can impair memory. Ideally, clinical skills are mastered first, and then stress management is taught as a separate skill. (Driskell and Salas 2013)
In a number of fields outside of medicine, stress inoculation therapy has been demonstrated to reduce the subjective sensation as well as objective markers of anxiety, decreased performance anxiety, and enhance performance under stress. (Driskell and Salas 2013; Gaab et al. 2006; Gaab et al. 2003; Hammerfald et al. 2006; Meichenbaum 1985; Saunders et al. 1996) Stress inoculation training appears to have value even after a limited number of training sessions, and the education seems to be generalizable to novel settings. (Petrosoniak and Hicks 2013; J. E. Driskell, Johnston, and Salas 2001; Grossman and Christensen 2004) Stress inoculation training has also be successful with a variety of different instructors, from trained psychologists to lay personnel after brief training sessions. (Meichenbaum 1985; Driskell and Salas 2013)
Stress inoculation training has been demonstrated to help reduce stress and improve performance in a number of professions, including police, military, athletes, teachers, and nurses. (Meichenbaum 1985) When lay people underwent stress inoculation training in addition to normal CPR training, they were more likely to use their skill is a test setting and performed more accurately. (Whitelock and Asken 2012) These studies are promising, and stress inoculation seems to generalize well, but if should be noted that there has not yet been any research demonstrating benefit of stress inoculation training in medicine.
A note about evidence: social science research often has weaker methodology than we are used to in medicine, but because stress exposure training started as a clinical intervention, the methods here are stronger. (Driskell and Salas 2013) One review, in which 85% of included studies were randomized trials, found that 67% of published trials reported statistically significant improvements in performance with stress exposure training. (Driskell and Salas 2013)
The goal of stress inoculation training is not to eliminate stress. No single stress management technique has been shown to be universally effective. The goal is to learn the nature of stress then develop and practice a variety of skills to draw on when necessary. (Meichenbaum 1985)
For an eye-opening and insightful firsthand account of how stress exposure training is done in the military, read “Stress Inoculation Training” by Mike Lauria
“Mindfulness is the skill of being deliberately attentive to one’s experience as it unfolds – without superimposition of our usual commentary and conceptualizing.” (Ludwig 2008) Studies have indicated that mindfulness can improve our ability to control focus and attention. (Deuster and Schoomaker 2015) Mindfulness has also been shown to improve working memory, and in particular, it may counter the impairment of working memory caused by stress. (Deuster and Schoomaker 2015) Mindfulness is also an effective tool in emotional self-regulation, as one learns to observes their emotional experiences without immediately reacting to or trying to change them. (Deuster and Schoomaker 2015)
The majority of our thoughts and emotions occur without our being actively aware of them. We often react automatically, without being fully aware of the emotional, social, and cognitive factors impacting our current state. There are almost as many definitions of mindfulness as there are articles, but for me the essence is simply promoting an active awareness of one’s body and thoughts. The only caveat is to approach that awareness non-judgmentally.
For example, through mindfulness, you might become aware of a tightness in your muscles that you recognize as indicating that you are becoming frustrated with a team member during resuscitation. Being non-judgemental means recognizing those sensations as normal responses to a normal human emotion that is neither good nor bad. The key to mindfulness in resuscitation is learning to recognize those sensations, acknowledge them, but then put them aside so you can focus on what is truly important to you: saving the patient. Putting these thoughts aside takes practice, but can also be helped by a number of the techniques discussed below, such as tactical breathing, self talk, and cognitive re-framing.
You can learn more about mindfulness meditation in Scott Weingart’s SMACC talk “Kettlebells for the Brain”
Although mindfulness is often spoken of as if it were a panacea of sorts, there is still a great deal we don’t know (like many of the topics discussed here). Is mindfulness equally effective for all people? Are there harms of mindfulness practice? How much training is required and what should that training look like?
Being mindful of attention
Concentration is not automatic. It takes a lot of energy to concentrate, and our ability to concentrate can become significantly impaired under stress. (Whitelock and Asken 2012; Grossman and Christensen 2004) Attention can be broad or narrow. In emergency resuscitation, we frequently require both kinds of attention. Broad awareness or situational awareness is essential for leading a resuscitation. However, when performing a specific skill like intubation we often require a much more narrow scope of focus. (Whitelock and Asken 2012)
We can probably improve our concentration skills through training. This is really the entire basis of mindfulness meditation strategies, but if meditation scares you, just focus on your concentration skills. Pick a small subject to focus on. It could be an external subject, like a laryngoscope blade, or it could be part of you, like your hand and the sensation of the laryngoscope as you hold it. Just focus on that subject. Take in all the details. Try to notice as many attribute as possible: the weight, the temperature, the size, the solidity. If you are focusing on your hand, pay attention to the feeling of the skin, the muscle tension, any pulsations you can feel. Practice maintaining this focus for as long as possible. If other thoughts come into your head, that is okay, because the key to improving focus is practicing bringing your attention back to the object after those distractions. As you improve, the exercise can be made more difficult by adding distractions, like music or TV in the background. You can also practice shifting your focus from narrow to broad and back again, by trying to focus only on the object to the exclusion of everything else for 30 seconds, and then shifting your attention broadly to everything in the room for 30 seconds, and then repeating. (Whitelock and Asken 2012) With time, this type of exercise should help you focus your attention where you need it in the resuscitation room, and to quickly switch back and forth from the broad situational awareness required to lead a resuscitation to the very narrow focus required to complete a procedure.
Jason Brooks talking about focus:
Overlearning is continuing to practice a skill after one is already competent. (LeBlanc 2009; Driskell and Salas 2013) One of the major benefits of overlearning is that once a skill is overlearned, it can be automated and therefore requires less concentration and working memory, potentially improving performance under pressure. (Whitelock and Asken 2012; Driskell and Salas 2013) Overlearning can also simplify more complex tasks, and simple tasks are less likely to be impaired under stressful conditions. (LeBlanc 2009; Driskell and Salas 2013) Overlearning might also create “muscle memory”, such that extensively practiced motor skills can still be relied upon under extreme stress. This has been demonstrated in police officers handling firearms and using handcuffs in “code red” even when other motor skills have deteriorated. (Grossman and Christensen 2004) Presumably, medical skills like vascular access would similarly benefit from overlearning. Finally, overlearning can increase one’s sense of control when performing a task. (LeBlanc 2009)
The major drawback of overlearning is that it may limit one’s flexibility when responding to complex and changing conditions; one’s response may be to stick too rigidly with the skill that has been overlearned. (LeBlanc 2009) There are many examples of people identically replicating training drills under extreme stress. My favorite is the story of a police officer who overlearned the technique of disarming a subject with a gun at close range. Every chance he got he would have his partner point a gun at him, snatch it away, and then hand it back to repeat the process. One day when responding to an armed robbery he came face to face with a suspect who had a gun pointed directly at the officer. The officer immediately snatched the gun away and successfully disarmed the suspect, but the next move he had overlearned through extensive practice wasn’t as smooth: he immediately handed the gun back to the suspect like he had so many times with his partner. Luckily, the suspect was so surprised that the officer managed to disarm him again, but the lesson is clear: you have to “practice like you play”, or make your practice sessions as close to real life as possible. (Grossman and Christensen 2004)
Overlearning should not be applied to all skills. You want to select skills that are likely to be universally adaptive as compared to those which may require more flexibility. You also want to avoid overlearning different possible responses to the same stimuli, as it could make deciding between the two option difficult under stress. (Driskell and Salas 2013) For example, I have applied the concept of overlearning to my surgical approach to a cricothyroidotomy, so it could be confusing to also attempt to overlearn a catheter based technique.
Mental practice (aka performance enhancing imagery)
Performance can be improved through practice, training, and experience. Once a response has been learned, it no longer requires the same higher order cognition. This allows you to more rapidly choose among prelearned responses. (Leach 2004) Real life experience or simulated education are excellent ways to prepare for high stress scenarios, but are time consuming and often impractical. Mental practice is just like physical practice, except that it occurs entirely within your mind. It involves visualizing, in as much detail as possible, each step of the skill to be practiced.
Multiple studies, of mixed quality, seem to indicate a benefit of mental practice in sports and music. (Weinberg 2008; Driskell, Copper, and Moran 1994) In medicine, mental practice has been shown to enhance surgical and procedural skills. (Arora et al. 2011; Komesu et al. 2009; Sanders et al. 2004; Sanders et al. 2008) More recently, mental practice was also shown to improve performance in team based trauma resuscitation simulations. (Lorello et al. 2016)
However, not surprisingly, considering the many possible interpretations of mental practice and the breadth of medicine, there are also studies that show no benefit. (Hayter et al. 2013) Furthermore, mental practice is probably less effective than actual physical practice. (Driskell, Copper, and Moran 1994)
Effectiveness is probably increased when the practiced skill is visualized carefully, correctly, incorporating all the senses, and in real time. (Herzog and Deuster 2014) Much like physical practice, lazy or sloppy mental practice is unlikely to translate into improved performance. The accurate visualization required for mental rehearsal means that at least some real world experience of physical practice is required before mental practice can be employed. (Whitelock and Asken 2012)
In addition to physical skills, mental practice can probably also be used to help train your emotional responses. Have you ever had a bad encounter while working, got angry, and said something that you later regretted? Take a moment to recreate that moment in your head. In real time, recreate the conversation. Now feel the physical changes that accompany your anger. Are your muscles tight? Your heart racing? Try to experience everything about the scene, right down to the smells in the room. Now that you can recognize the anger developing, picture yourself responding as you wish you had acted rather than as you actually did. Envision yourself taking a few deep breaths. Try to see things from the other side. Is this person really a jerk, or are they just scared or tired or struggling with their divorce? Envision yourself pausing to breath and think before you respond. If you mentally rehearse both the sensations of anger and your planned response, you are much more likely to recognize when you are becoming angry, and respond in a way that that fits with your professional ideals.
Locus of control
A feeling of control is essential for managing stress performing optimally. (Driskell and Salas 2013) Unfortunately, emergency medicine is incredibly unpredictable, so control is not always possible. However, there are many ways you can improve your sense of control. If your department doesn’t stock the right equipment or have the right protocols, don’t feel helpless, get involved. Taking control of your working environment can go a long way towards mitigating the stress of managing critically ill patients
The importance of feeling in control is also an important consideration for team leaders. As physicians, decisions in resuscitation generally rest with us. This can seem stressful, but it is also important to consider the perspectives of other team members. Feeling like you don’t have a voice is incredibly stressful. Participation in decision making gives people the sense that they are in control, and therefore significantly decreases perceived stress. (Driskell and Salas 2013) In stressful resuscitations, it is a good idea to involve the entire team in decision making, both because you benefit from others’ experience, but also because it helps the team manage stress. (It is also worth keeping in mind that stress is subjective, and resuscitations that seem routine to you might be incredibly stressful for the newly graduated nurse in the room. Look after your team.)
Having a plan of action limits indecision. You will take more time to make a decision when you have more options available to you. In basic psychology lab experiments, William Hick demonstrated that when the number of possible responses to a stimulus increased from one to two, reaction time slowed by 58%. (Hick 1952) Hick’s law describes the increased decision time based on increasing number of options.(Grossman and Christensen 2004) How accurately this rule applies to the more complex decisions we make in medicine, and how that balances with the potential negative consequences of artificially decreasing options is not clear. However, I think this concept can be extrapolated to the resuscitation room. We know that there are decisions that are hard for physicians to make, like the decision to proceed with a cricothyroidotomy. Adding complexity to that decision by making yourself decide between a surgical and needle based approach will likely prolong time to action under extreme stress. Therefore, for time critical interventions like a cricothyroidotomy, I think it is important to choose just a single technique, and drill that technique (both physically and mentally) until it becomes automatic, so that you won’t stumble with the decision under pressure.
The 2% rule: Take a moment to consider and envision how you would manage rare complications
One topic that I find fascinating, but I have not seen addressed at all in medicine, is ergonomics. For example, in aeronautics, there is great deal of literature comparing status displays and command displays. A status display always provides information, such as altitude. A command display, on the other hand, gives you instructions in response that information: “Pull up! Pull up!” (Driskell and Salas 2013) Imagine if our pulse oximeters, rather than just displaying a number, could instruct us: “Stop laryngoscopy, insert LMA”.
Stress preparation: evidence in medicine
Wetzel et al performed a randomized control trial in which surgeons were randomized to a fairly involved (but not complicated) stress management training program or control. (See the figure below for an overview of their stress management program). The surgeons in the intervention group demonstrated improved teamwork, coping skills, and physiological markers of stress in a simulated difficult surgery. (Wetzel et al. 2011)
Optimal Performance: In the moment
There are a massive number of different ways that humans regulate their emotions, before, during, and after emotional incidents. You can punch a pillow. You can exercise. You can vent to your friends. You can take a nap. You can bite your lip or fingernails. You can focus on your breathing. You can ignore the situation altogether, or walk away, or quit. (Gross 2015) Our goal is to find the strategies that are effective and appropriate for managing our emotions in a clinical environment.
In emergency medicine, the primary focus is almost always going to be on decreasing arousal. We are constantly overloaded with stressors, which combined with the high acuity of our patients, rarely allow us to be overly relaxed. However, even in emergency medicine, there will be times that we will need to increase our arousal. Maybe you are working a night shift at a small hospital where you can actually sleep at times and you are paged out of a deep sleep. You might be fatigued at the end of a long shift, or just lack energy right from the start, or feel bored. In these states of low arousal, how can we ensure that we perform optimally when a critically ill patient is suddenly dropped in our laps?
One option, if you have time, is physical warm up. (Whitelock and Asken 2012) Prior to a night shift, when I know I will be fatigued, I always try to get a little bit of exercise in. At 4 am, if I feel myself fatiguing, I might go jog up and down the stairs for 5 minutes. Even just a few jumping jacks might help.
Cue words or images can help you focus on the situation at hand. Simply telling yourself “focus”, “think”, or “let’s go”, can help increase your level of arousal. Similarly, picturing yourself in the midst of an emergency situation can definitely get your heart rate up. Self efficacy statements, like “I’m feeling good”, “I’m ready”, or “I’ve got this” can also boost confidence. (Whitelock and Asken 2012)
Finally, music is a great example of a tool that can get you into the right mindset. You will often see high level athletes with headphones on immediately prior to their event for just this reason. Some high tempo music can increase your arousal when you are feeling a bit slow. (Whitelock and Asken 2012)
Arousal Control Techniques
A number of techniques have been described to try to control arousal. Meditation, self-hypnosis, biofeedback, progressive muscle relaxation, and relaxation imagery have all been described as ways of curtailing the body’s physiologic reactions to stress. (Whitelock and Asken 2012)
Consider the autonomic system’s response to stress: your heart races, your blood pressure rises, you sweat. Try to control any of those features right now. Feel your pulse and then consciously slow it down. Make yourself stop sweating on demand. It’s just not possible.
Under stress, breathing tends to become quick and shallow. Unlike a rapid heart rate or sweating, breathing is the one manifestation of the autonomic nervous system that we can actually take control over. (Grossman and Christensen 2004) There are a number of described performance or tactical breathing techniques to manage stress and arousal. One example is the ‘square breathing’ technique, where you inhale slowly over 4 seconds, hold for 4 seconds, exhale slowly over 4 seconds, and then pause for 4 second before starting again. (Whitelock and Asken 2012)
The importance of breathing isn’t exactly novel information. Breathing for performance and relaxation is taught in almost every discipline. Breathing is central to yoga and meditation. It is used by musicians, athletes, and martial artists. It is an essential tool in competitive marksmanship. We even tell our anxious patients, or those in pain, to take some nice deep breaths. We just seem to overlook its value when it comes to our own performance.
Ideally, breathing techniques are combined with the other strategies discussed below, such as self talk. As you slowly exhale, say to yourself, “I’ve got this. Just focus on … “
Of course, like everything discussed here, there is still a lot to learn. There is reasonable evidence that breathing works to control stress, but the specifics are lacking. Is there an ideal pattern to breathing? How many cycles are required? Does it have similar effects for everyone? What are the downsides? (Grossman and Christensen 2004)
How you think shapes how you see the world.
Self talk or self instruction has been shown to influence one’s appraisal of stress, attention, and physiologic reactions to stressors. (Meichenbaum 1977; Meicheribaum and Novaco 1985) Self talk is a major component of most stress inoculation programs. It can be used as a mechanism to assess the demands of a situation and plan for stressors; to control negative thoughts and images; to acknowledge, use, or relabel the sensation of arousal; or to “psych” oneself up. (Meichenbaum 1985)
Self talk can be either positive or negative. Obviously, for managing pressure and optimizing performance we want to focus on increasing positive self talk while minimizing negative. (Whitelock and Asken 2012)
There are a number of topics that self talk can focus on, but only self talk that is positive and focused on the specific task at hand will be truly helpful. “I’ve got this” or “I can do this” are positive statements that can help with motivation, but are not ideal because they do not help you act. “I know how to do this. Focus. Uvula, epiglottis, cords, pass the tube” is a better example of self talk because it is both positive and goal directed. (Whitelock and Asken 2012)
We are all very familiar with negative self talk. Self doubt is part of being human. Imagine you are working single coverage in a small town hospital and a school bus rolled over at high speed with multiple pediatric trauma casualties all arriving in your department at the same time. It would be pretty natural to say to oneself: “This is too many patients. I’ve never trained for this. I can’t handle this. We don’t have enough people. We just aren’t prepared.” The idea of positive, constructive self talk is to change that inner dialogue to something more like: “OK, I’ve got this. One at a time. Rapid assessment, airway maneuver, triage, then next patient.” (Whitelock and Asken 2012)
It is very hard to get yourself not to focus on something. Try it: for the next minute, don’t think about your left hand. It just doesn’t work. This is why good golfers don’t focus on avoiding the water, but instead just focus on the center of the fairway. Similarly, if you are performing a cricothyroidotomy, don’t tell yourself to “ignore the blood”. Instead, tell yourself “feel the membrane”. (Whitelock and Asken 2012)
A topic I think of as related to self talk, but with a longer time scale, is personal affirmations. Affirmations are positive, truthful statements that we make about ourselves to ourselves. They are not boasts, just statements about our skills and abilities. We don’t all have the same skills, but we all bring some amazing skills to the table. The point of affirmations are to recognize the unique qualities and skills that you bring to the table. They give you a positive identity anchor when you are doubting yourself or wondering why you chose this line of work. (Whitelock and Asken 2012) Some research has demonstrated that affirmations may reduce the physiological impacts of stressful situations and have the ability to change behaviours.
I did not feel prepared for my first solo shifts after residency. Walking towards the hospital, I could feel my heart rate increase and the perspiration start. What if I made a horrible mistake? The worry put me in a bad mental state starting my shifts and the stress would just build from there. Without knowing any of the terminology, I found myself practicing self talk and focusing on personal affirmations. Walking up to the hospital, I would tell myself, “OK Justin, You can do this. You have worked hard and you know what you are doing. You are going to make sure you have a truly positive influence in 10 people’s lives today and that will be a good shift. You are going to concentrate so that you don’t make any mistakes and you aren’t a negative influence in anyone’s life”. It sounds really corny, but talking to myself on the way through the hospital door really gave me the confidence to get through those shifts.
Focus or cue words
This is a technique for regaining focus in stressful, chaotic situations. The idea is to have a few key cues that guide you through the scenario. If you find yourself getting lost, you use these cues to get you back on track. (Whitelock and Asken 2012) My favorite example of this technique is the way that Rich Levitan teaches challenging airways. When you are lost, unable to identify landmarks, and feel the stress rising, Dr. Levitan suggests a series of simple cues to guide you: “find the uvula… now that I am midline, find the epiglottis…”
Cognitive reframing or reappraisal
Cognitive reframing is modifying your appraisal of a situation in order to alter its emotional impact. (Gross 2015) Cognitive reappraisal is a centerpiece of cognitive behavioral therapy. (Jamieson et al 2013) A common example in emergency medicine might be reminding yourself, in the middle of a bad resuscitation, that the patient isn’t you or a family member, to lessen the emotional impact of the scenario.(Kross and Ayduk 2011) Likewise, before interviewing for a new job (or residency position) you might remind yourself: “this interview isn’t do or die; I have other options, and it will be a great experience and chance to meet people, no matter what the outcome.” Or in a multi-trauma scenario, simply reminding yourself: “although this feels overwhelming, I am well trained and I know I can handle this situation if I stick to my training.”
Another form of cognitive reframing, which has been demonstrated to aid performance, is to acknowledge the physiologic changes of stress (the racing heart and sweaty palms), but rather than viewing them as a hindrance or distraction, reframing them as a beneficial sign that your body is operating a peak levels. (Jamieson et al 2013; Jamieson et al 2012) Therefore, reframing can be used to either decrease physiologic arousal or as a way to accept the heightened arousal and use it to optimize performance. (Jamieson et al 2013)
There is a fair amount of evidence that, when used to down regulate negative emotions, this kind of cognitive change does actually decrease the subjective experience of negative emotions. (Feinberg et al. 2012; Gross 2015) Objective changes, such as decreased activation of the sympathetic nervous system and amygdala, and improved cardiac function have also been noted. (Jamieson et al 2013; Jamieson et al 2012; Gross 1998) It may also improve performance, such as memory and performance on exams. (Jamieson et al. 2010; Jamieson et al2013) These effects may be long lived, as positive effects were seen on exam scores even when the exam was taken 1-3 months after the education session on cognitive reappraisal. (Jamieson et al. 2010)
The effectiveness of cognitive reframing is a reminder that stress is transactional. Stress is neither an external aggravation nor an internal response, but an interaction between your thoughts and the environment. Unfortunately, our cognitive appraisals can also work against us. Many people inadvertently increase stress though negative appraisals, such as “I can’t do this”. This can produce a negative feedback loop, in which you project negativity (for example, uncertainty or anger) into the situation, which makes the situation worse, further increasing your stress. Learning to break this cycle and develop positive appraisals is essential. (Meichenbaum 1985)
Simon Sinek on reinterpreting nervousness as excitement:
Dealing with negative thoughts
Negative thoughts are going to happen. It’s just part of being human. Some people will experience more than others, but having a strategy to deal with negative thoughts is essential. First, you need to break the cycle. If you are alone, you could actually say loudly “stop it!” In groups, this is probably best left as internal monologue, but a firm “stop it” will, at least temporarily, stop the bad thoughts. Next, you have to realize that it is almost impossible to directly suppress thoughts. (Wegner 1989) (Again, try to not think about your left hand right now.) However, distraction or refocusing works well. So the command “stop it” should be followed by something different than the negative thoughts, like “back to it” or “reassess the ABCs”.
Perhaps the most difficult part of dealing with negative thoughts is noticing that they are happening. Negative thoughts are generally automatic. They occur rapidly and seemingly “out of the blue”. As a result, when they are noticed, they may not be recognized as fallible thoughts, but instead seem like incontrovertible facts. Think about your daily work. How often do thoughts like “GOMER”, or “this patient is just too old to survive”, or “why are we doing this?” pop into your head? Sometimes they just feel like the truths of emergency medicine, but really they represent an internal, subjective dialogue this is actively shaping your attitude, actions, and stress. This is why “thought catching” or trying to actively monitor one’s thoughts is an essential part of most stress inoculation programs. (Meichenbaum 1985) When you notice these thoughts, try asking yourself: is this automatic thought a valid fact, or just a manifestation of my current frustration?
One clue that you may be experiencing maladaptive automatic thoughts is the use of absolute words. Words like “never”, “must”, and “always” – as in “these patients never survive” – are hints that your thinking is flawed. Similarly, over-generalization and black and white terms are frequently found in faulty, automatic thinking. The goal is to rephrase. “Never” becomes “rarely”; “always” becomes “often”; “I must” becomes “I want”; “I need” becomes “I prefer”; “I can never” becomes “in the past I have been unable to”; and “I can’t” becomes “I find it difficult to”.
Replace “if” with “when”
A powerful example of cognitive reframing is replacing “if” with “when”. Knowing that you will perform a cricothyroidotomy IF you encounter a can’t intubate, can’t oxygenate situation is fine, but allows for a sense of denial that might slow your recognition that you are actually in that state. On the other hand, stating that you will cut the neck WHEN this intubation fails, conveys greater certainty, and mentally prepares you to take the next step. (Whitelock and Asken 2012)
A lot of the above is summarized in Mike Lauria’s mnemonic – Beat The Stress Fool – which stands for:
- Breath (tactical breathing)
- Talk (self talk)
- See (visualization)
- Focus (or any keyword to bring yourself back into the present)
You can hear him talk about this in this talk “Cognitive paths through chaos”:
Another note on the importance of practice
All of these optimal performance techniques require you to have underlying medical skills if they are going to help. Telling yourself “I can do this” won’t help you if you actually can’t do it. Positive self talk won’t get you through an awake intubation if you don’t understand and haven’t practiced the technique. Practice, both physical and mental, is essential before any of these techniques can help.
Stress impairs working memory. Therefore, the more we can do to offload our working memory the better we are likely to perform.
All the hard work for cognitive offloading really has to be done ahead of time. There are a number of different strategies. The classic, although relatively simplistic example is the large poster of the ACLS algorithms that is often taped to the a resuscitation room wall so it doesn’t have to be memorized. Checklists, although often denigrated in emergency medicine, are an excellent method to offload non-essential thinking. Standardization is a related and important concept. Having a standard approach and standard set of equipment eliminates guess work under pressure. Having the same difficult airway cart, with the same equipment, in the ED, ICU and OR means that you will easily be able to find the same equipment no matter where you are. You won’t waste cognitive work searching for tools or trying to think of an acceptable alternative to what you are used to. Finally, pre-made decision points or triggers help lighten the decision making load. If you know that after 2 failed looks with a laryngoscope you are always going to insert an LMA, you don’t have to think about it in the moment, you will just do it.
Cognitive stop points
Recognizing that we rely more heavily on rapid decision making strategies and heuristics under pressure, cognitive stop points are times in a resuscitation specifically designed for you to slow down, step back, and consider your reasoning. Ideally, they occur at moments when you have the time to think, but also when the decisions being made are more complex. For example, in the first 15 minutes with a patient in septic shock, almost everyone is going to get the same management: large fluid boluses, antibiotics, and norepinephrine. However, if the blood pressure remains low after fluid and a reasonable dose of a vasopressor, that should trigger some thought. This patient is more complex than the average septic shock patient. Are you missing an alternative diagnosis, like anaphylaxis? Is the patient on chronic steroids and requiring a stress dose?
In my mind, there are two major types of cognitive stop points. Natural cognitive stop points occur at naturally occurring breaks in resuscitation, such as when the patient is being packaged up to go to CT. These are excellent times to slow down and really think about your thinking. Intuitive stop points are harder to identify, but probably more important. These should occur when a resuscitation is just not progressing like you expect. There isn’t a set trigger, but the failure of the patient to respond to usual treatments should result in a change in thinking. Before forging ahead, you must consider whether this failure to respond is because of an earlier failure in decision making (misdiagnosis).
Optimal Performance: After the event
The immediate aftermath (adrenaline dump or parasympathetic backlash)
How do you feel when you walk out of a stressful resuscitation? Personally, I feel like sh**. I am utterly drained. Even the smallest task seems mountainous.
After an experience of extreme stress, in which the sympathetic nervous system has been in overdrive and your system has been flooded with stress hormones, there will be a let down; a withdrawal from the sympathetic arousal. This is what Grossman refers to as the parasympathetic backlash. (Grossman and Christensen 2004) The parasympathetic backlash is what makes getting back to work immediately after a resuscitation so difficult. It is what makes us let our guard down, so that after an extremely stressful intubation, we forget about post-intubation sedation or other ongoing aspects of resuscitation.
So how should we deal with this backlash? The most important step, like much of what is discussed here, is simply to acknowledge that it exists. We are human, and this will be a period of vulnerability. Next, you need to regain situational awareness. In the military, as well as in martial arts, after any victory or accomplished goal, you are trained to perform an immediate 360 degree sweep of your surroundings. (Grossman and Christensen 2004) I think this applies in medicine as well. After any stressful intervention, your immediate first step should be to repeat the primary survey. It is hard to remember of all the things you might need to do for these patients, so this is an excellent time to use a checklist. A post intubation checklist, a pre-CT checklist, or a pre-transfer checklist are all excellent tools that will help your mind through a period of vulnerability. Finally, if at all possible, admit that you are human and take a brief break. Take some deep breaths, drink some water, have a snack, and just sit down for 5 or 10 minutes.
Sometimes, you will have a massive release of adrenaline but not have the opportunity to use it. It might be a paramedic patch informing you about a sick neonate on the way, only to find out 5 minutes later they bypassed to another hospital. Or, you might have a confrontation with a consultant, only to get hung up on, so that nothing is resolved. Whatever the cause, the result is that you are left with an excess of adrenaline without any need for it. You cannot perform at a high level in this state. You have to find some way to burn off the excess adrenaline.
There are a number of options. Exercise is often recommended, but difficult to do in the middle of a shift. I know there are departments that have a punching bag in a back room, and that is a great way to release some excess energy. Tactical breathing can help, as can meditation. Finally, sometimes you just need to take some time. Taking 10 minutes to walk away from the department, drink some water, and have a snack can make all the difference in bringing you back to your baseline.
Although there are probably more technical definitions, I like this simple definition: “a debriefing is any discussion after an event that helps the participants come to terms with it, and learn from it.” (Grossman and Christensen 2004, pg 303) When phrased that way, you can’t ignore the value of a debrief. We all need learn and we all need to cope.
When a patient dies, our first instinct is often, “what a waste”. A waste of a life lost too early, but also a waste of our time, resources, and emotions. We lost. But these deaths should not be looked at as a waste. They are a time to learn. What went wrong? What went right? What can we do better in the future?
Other fields recognize the problems of poor or faulty memory under extreme stress and use the debrief as a method to clarify events. (Grossman and Christensen 2004) In medicine, we generally just expect the doctor to remember things and chart perfectly. This is a mistake. We work in teams for a reason. Talk to your nurses. Review the resuscitation documentation. Use everyone’s help to accurately chart.
More importantly, the debrief is an important time to check in with our team. We are all human, and the natural response to stress and tragedy is guilt. (Grossman and Christensen 2004) Currently, we go our separate ways and all lie in our beds sleepless as the events replay again and again in our minds. We are lost in the land of “what if”. But voicing your pain can help. Discussing your concerns can be a path out of the land of “what if”. “Pain shared is pain divided”. (Holmes et al. 2009; Grossman and Christensen 2004)
Some guiding principles for debriefing: (Grossman and Christensen 2004)
- Individuals should not be forced to participate. Explain that it is voluntary, but also explain why it is important.
- It must be done at the right time by the right person. A quick debrief immediately after an event is appropriate, but it should not significantly interfere with clinical responsibilities, and it should never keep someone from getting home to their loved ones. The debrief should be led by an insider: someone who understands the situation and is trusted is ideal.
- The place is important. Ideally, you want to be removed from the environment that the stressor took place in.
- Debriefing should not stand alone. It should be offered in the context of ongoing psychological support.
The debrief should normalize reactions. Immediately after an experience, you might experience nausea, upset stomach, dizziness, trembling, sweats, chills, or the need to use the bathroom. You might have sleep disturbances or nightmares. Later, you might find yourself preoccupied with the incident, replaying it over and over in your mind. You might doubt your ability. You might feel angry, sad, vulnerable, self-conscious, or scared. You might be happy that you survived while others didn’t. That might make you feel guilty. Or you might not experience any of that. Some people have all of these symptoms, while others have none. Whatever your reaction, what is important is understanding that it is perfectly normal. (Grossman and Christensen 2004)
A key component of the debrief should be to focus on separating the memory of an event from the sensation of sympathetic nervous system arousal. Talking about the event will invariably bring up negative emotions. When the symptoms arise, use tactical breathing to work through it. (Grossman and Christensen 2004)
Although our culture revolves around coffee, don’t offer or drink coffee. It will make all the post-stress adrenergic symptoms worse, and contribute to sleep difficulties later. (Grossman and Christensen 2004)
Coping after stress
Emergency medicine has one of the highest levels of burnout in medicine. PTSD is far too common among paramedics (and probably just not talked about as much among nurses and doctors). How we cope with horrendous situations is a very important topic, but unfortunately one that I am under qualified to talk about.
There are a number of factors that have been shown to promote resilience. Positive supports systems, attention to clinician well-being, and active coping mechanisms are important. People who have access to psychological support in demanding situations are healthier. (LeBlanc 2009) Cognitive behavioural therapy can bolster the ability to engage others for help, as well as improving optimism, faith, and self-care. Self care activities might include exercise, expressive writing, and mindfulness based stress reduction. (Mealer et al. 2014) Unfortunately, these interventions are complex, and it isn’t clear that they are always effective. (Mealer et al. 2014)
I am fascinated by the work that indicates that playing tetris, by interfering with the visuospatial pathways used in flashbacks, can decrease PTSD. (Holmes et al. 2009) (Note of bias: I love Tetris, and used to play so much that at one point I held the Canada wide high score after the Nintendo Wii came out).
This is a very underwhelming summary of an incredibly important topic. I hope to address that at some point. If you have some expertise in the aftermath of stress and have any advice you think would be helpful to emergency personnel, feel free to drop me a line.
Team performance is obviously an essential aspect of performance under pressure in the resuscitation room. Individual performance can only go so far. The literature on team performance probably warrants its own post, but I will provide a very brief overview here.
The literature on team performance tends to focus on a few key domains. The ability of teams to adjust to changing demands is covered by theories of team adaptation and self-regulation. Task cohesion, the degree to which members of a team work together to achieve a common goal, is an important factor in optimal team performance. (Carron et al. 2002) Team communication in stressful scenarios focuses on the idea of shared mental models and common ground. Leadership research examines the roles of leaders and the social dynamics of teams. (Salas et al 2007)
Stress impairs team performance in a number of ways. Under stress, individual priorities are often given precedence over those of the team. The narrowing of perception of team members caused by stress limits their ability to identify social cues. (Driskell and Salas 2013) Teams lose perspective. (Salas et al 2007; Driskell et al 1999; Flowerdew et al. 2012) This loss of perspective is usually accompanied by a decrease in explicit communication among team members. Interestingly, although team leaders actually become more open to input from team members in high stress environments, team members are less likely to provide input under stress. (Salas et al 2007)
Under stress, attention is focused on perceived high-priority items, to the exclusion of those perceived to be lower priority. One explanation for the deterioration of team performance under stress is that teamwork behaviours such as coordination and communication are perceived to be lower priority. Therefore, teamwork under pressure could potentially be strengthened with training programs that illustrate and emphasize the importance of teamwork in crisis situations. (Driskell et al 1999; LeBlanc 2009)
We have one major factor against when it comes to team performance in emergency medicine: constantly changing team members. By the nature of our schedules, and the number of different individuals who make up our teams, we almost never have exactly the same team in resuscitation room. This is somewhat crazy in such a high stakes environment. Imagine a sports team in the playoffs putting out a different starting lineup for every game. The coach would be fired. But this is simply our reality. That being said, even great teams must have depth and will have to withstand injuries. Training the weakest member of your team, so that you can perform at a high level no matter what the substitution, is essential.
It is pretty clear that team dynamics and function change under stress, but the ultimate impact of that change on real world performance is less clear. For example, the change from explicit communication to implicit might help team maintain performance under time pressures. (Kowalski-Trakofler et al 2003)
Shared mental models
A mental model is a cognitive construct that allows a person to “predict and explain the behaviour of the world around them among others and to construct expectations for what is likely to occur next”. (Petrosoniak and Hicks 2013) Optimal team behaviour occurs when team members can predict each others’ needs instead of having to talk about them; in other words, when team members have a shared mental model. (Petrosoniak and Hicks 2013; LeBlanc 2009)
Traditional team communication focuses on clarity, using team’s members names, and closed loop communication. However, this still requires explicit communication. Training in interdisciplinary teams and cross-training (training in other teams members’ positions to gain a better understanding of each team member’s role) could increase shared mental models and allow a shift from explicit to more implicit communication. (Petrosoniak and Hicks 2013)
Important factors for high performance teams from (Salas et al 2007)
- Leadership matters: a team leader can improve performance by exhibiting behaviours that promote teamwork such as coordination and cooperation.
- Team members must have clear roles and responsibilities: this allows teams members to have accurate expectations of their team mates’ actions and needs during high stress scenarios.
- Shared understanding of task and objectives (task cohesion) is important
- Good teams make a habit of performing both a pre-brief and a debrief.
- Team emotional affects matter
- Clinical expertise is necessary, but not sufficient. Cooperation, communication, and coordination skills matter.
- Teams must have clear visions
- Learning from mistakes, self-correction and adaptability are the hallmarks of high performances teams.
That was a long, eclectic dump of information. It was meant primarily as a reference – a place for me to keep my notes. It wasn’t designed to have a single, clear take home message. However, if there is just one takeaway point it is this: we are all human. We can’t escape it. Stress is part of our jobs, and stress has significant impacts on how we perform. In emergency medicine, we will never eliminate that stress. Therefore, it is essential that we practice a number of the tools discussed here to ensure that we are always able to perform at our best, even under extreme pressure.
Other FOAMed Resources
There is a full list of references below, but many of them are lengthy, technical, difficult reads. Here is a short list of resources that I found easy to read and I think provide a great introduction to the issues discussed here.
LeBlanc, Vicki R. 2009. “The Effects of Acute Stress on Performance: Implications for Health Professions Education.” Academic Medicine: Journal of the Association of American Medical Colleges 84 (Supplement): S25–33.
- I think this is a the best academic overview of the issues of acute stress and performance in medicine.
- Although focused on military performance, this book is an incredible summary of the impacts of stress on human performance that I think generalizes pretty well to medicine.
- A very short read, aimed specifically at paramedics, that covers most of what I have discussed here, with specific exercises designed to help you improve your stress management skills.
- This is the least technical of the books specifically on performance under pressure, and was a quick, enjoyable read.
- This is a nice introduction to mindfulness meditation without requiring any ties to religion or energy fields.
- Some very interesting thoughts on relaxation and mindset by the guy who was the basis of the movie “Searching for Bobby Fischer”
Arora, Sonal, Rajesh Aggarwal, Pramudith Sirimanna, Aidan Moran, Teodor Grantcharov, Roger Kneebone, Nick Sevdalis, and Ara Darzi. 2011. “Mental Practice Enhances Surgical Technical Skills: A Randomized Controlled Study.” Annals of Surgery 253 (2): 265–70.
Arora, Sonal, Nick Sevdalis, Rajesh Aggarwal, Pramudith Sirimanna, Ara Darzi, and Roger Kneebone. 2010. “Stress Impairs Psychomotor Performance in Novice Laparoscopic Surgeons.” Surgical Endoscopy 24 (10): 2588–93.
Bjørshol, Conrad Arnfinn, Helge Myklebust, Kjetil Lønne Nilsen, Thomas Hoff, Cato Bjørkli, Eirik Illguth, Eldar Søreide, and Kjetil Sunde. 2011. “Effect of Socioemotional Stress on the Quality of Cardiopulmonary Resuscitation during Advanced Life Support in a Randomized Manikin Study*.” Critical Care Medicine 39 (2): 300–304.
Carron, Albert V., Michelle M. Colman, Jennifer Wheeler, and Diane Stevens. 2002. “Cohesion and Performance in Sport: A Meta Analysis.” Journal of Sport and Exercise Psychology 24 (2): 168–88.
Christensen, Loren W. 1997. Deadly Force Encounters: What Cops Need To Know To Mentally And Physically Prepare For And Survive A Gunfight. Paladin Press.
Cumming, Steven R., and Lynne M. Harris. 2001. “The Impact of Anxiety on the Accuracy of Diagnostic Decision-Making.” Stress and Health: Journal of the International Society for the Investigation of Stress 17 (5): 281–86.
Deuster, Patricia A., and Eric Schoomaker. 2015. “Mindfulness: A Fundamental Skill for Performance Sustainment and Enhancement.” Journal of Special Operations Medicine: A Peer Reviewed Journal for SOF Medical Professionals 15 (1): 93–99.
Diamond, David M., Adam M. Campbell, Collin R. Park, Joshua Halonen, and Phillip R. Zoladz. 2007. “The Temporal Dynamics Model of Emotional Memory Processing: A Synthesis on the Neurobiological Basis of Stress-Induced Amnesia, Flashbulb and Traumatic Memories, and the Yerkes-Dodson Law.” Neural Plasticity 2007: 60803.
Dörner, Dietrich, and Erdmut Pfeifer. 1993. “Strategic Thinking and Stress.” Ergonomics 36 (11): 1345–60.
Driskell, James E., Carolyn Copper, and Aidan Moran. 1994. “Does Mental Practice Enhance Performance?” The Journal of Applied Psychology 79 (4): 481–92.
Driskell, James E., and Eduardo Salas. 2013. Stress and Human Performance. Psychology Press.
Driskell, James E., Eduardo Salas, and Joan Johnston. 1999. “Does Stress Lead to a Loss of Team Perspective?” Group Dynamics: Theory, Research, and Practice: The Official Journal of Division 49, Group Psychology and Group Psychotherapy of the American Psychological Association 3 (4): 291–302.
Driskell, J. E., J. H. Johnston, and E. Salas. 2001. “Does Stress Training Generalize to Novel Settings?” Human Factors 43 (1): 99–110.
Feinberg, Matthew, Robb Willer, Olga Antonenko, and Oliver P. John. 2012. “Liberating Reason from the Passions: Overriding Intuitionist Moral Judgments through Emotion Reappraisal.” Psychological Science 23 (7): 788–95.
Fernandez, Rosemarie, John A. Vozenilek, Cullen B. Hegarty, Ivette Motola, Martin Reznek, Paul E. Phrampus, and Steve W. J. Kozlowski. 2008. “Developing Expert Medical Teams: Toward an Evidence-Based Approach.” Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine 15 (11): 1025–36.
Flowerdew, Lynsey, Ruth Brown, Stephanie Russ, Charles Vincent, and Maria Woloshynowych. 2012. “Teams under Pressure in the Emergency Department: An Interview Study.” Emergency Medicine Journal: EMJ 29 (12): e2.
Gaab, J., N. Blättler, T. Menzi, B. Pabst, S. Stoyer, and U. Ehlert. 2003. “Randomized Controlled Evaluation of the Effects of Cognitive-Behavioral Stress Management on Cortisol Responses to Acute Stress in Healthy Subjects.” Psychoneuroendocrinology 28 (6): 767–79.
Gaab, J., L. Sonderegger, S. Scherrer, and U. Ehlert. 2006. “Psychoneuroendocrine Effects of Cognitive-Behavioral Stress Management in a Naturalistic Setting–a Randomized Controlled Trial.” Psychoneuroendocrinology 31 (4): 428–38.
Gross, James J. 1998. “The Emerging Field of Emotion Regulation: An Integrative Review.” Review of General Psychology: Journal of Division 1, of the American Psychological Association 2 (3): 271–99.
Gross, James J. 2015. “Emotion Regulation: Current Status and Future Prospects.” Psychological Inquiry 26 (1): 1–26.
Grossman, Dave, and Loren W. Christensen. 2004. On Combat: The Psychology and Physiology of Deadly Conflict in War and in Peace. Human Factor Research Group Incorporated.
Hammerfald, K., C. Eberle, M. Grau, A. Kinsperger, A. Zimmermann, U. Ehlert, and J. Gaab. 2006. “Persistent Effects of Cognitive-Behavioral Stress Management on Cortisol Responses to Acute Stress in Healthy Subjects–a Randomized Controlled Trial.” Psychoneuroendocrinology 31 (3): 333–39.
Harvey, Adrian, Glen Bandiera, Avery B. Nathens, and Vicki R. Leblanc. 2011. “Impact of Stress on Resident Performance in Simulated Trauma Scenarios.” The Journal of Trauma, July. doi:10.1097/TA.0b013e31821f84be.
Hayter, M. A., M. D. Bould, M. Afsari, N. Riem, M. Chiu, and S. Boet. 2013. “Does Warm-up Using Mental Practice Improve Crisis Resource Management Performance? A Simulation Study.” British Journal of Anaesthesia 110 (2): 299–304.
Herzog, Timpthy P., and Patricia A. Deuster. 2014. “Performance Psychology as a Key Component of Human Performance Optimization.” Journal of Special Operations Medicine: A Peer Reviewed Journal for SOF Medical Professionals 14 (4): 99–105.
Hick, W. E. 1952. “On the Rate of Gain of Information.” The Quarterly Journal of Experimental Psychology 4 (1): 11–26.
Jamieson, Jeremy P., Wendy Berry Mendes, Erin Blackstock, and Toni Schmader. 2010. “Turning the Knots in Your Stomach into Bows: Reappraising Arousal Improves Performance on the GRE.” Journal of Experimental Social Psychology 46 (1): 208–12.
Jamieson, Jeremy P., Wendy Berry Mendes, and Matthew K. Nock. 2013. “Improving Acute Stress Responses: The Power of Reappraisal.” Current Directions in Psychological Science 22 (1): 51–56.
Jamieson, Jeremy P., Matthew K. Nock, and Wendy Berry Mendes. 2012. “Mind over Matter: Reappraising Arousal Improves Cardiovascular and Cognitive Responses to Stress.” Journal of Experimental Psychology. General 141 (3): 417–22.
Kahneman, Daniel. 2011. Thinking, Fast and Slow. Doubleday Canada.
Klein, Gary. 2008. “Naturalistic Decision Making.” Human Factors 50 (3): 456–60.
Komesu, Yuko, Rebecca Urwitz-Lane, Begum Ozel, James Lukban, Margie Kahn, Tristi Muir, Dee Fenner, and Rebecca Rogers. 2009. “Does Mental Imagery prior to Cystoscopy Make a Difference? A Randomized Controlled Trial.” American Journal of Obstetrics and Gynecology 201 (2): 218.e1–9.
Kowalski-Trakofler, Kathleen M., Charles Vaught, and Ted Scharf. 2003. “Judgment and Decision Making under Stress: An Overview for Emergency Managers.” International Journal of Emergency Management 1 (3): 278.
Krage, R., L. Tjon Soei Len, P. Schober, M. Kolenbrander, D. van Groeningen, S. A. Loer, C. Wagner, and L. Zwaan. 2014. “Does Individual Experience Affect Performance during Cardiopulmonary Resuscitation with Additional External Distractors?” Anaesthesia 69 (9): 983–89.
Kross, Ethan, and Ozlem Ayduk. 2011. “Making Meaning out of Negative Experiences by Self-Distancing.” Current Directions in Psychological Science 20 (3): 187–91.
Leach, John. 2004. Why People “Freeze” in an Emergency: Temporal and Cognitive Constraints on Survival Responses.
LeBlanc, Vicki R. 2009. “The Effects of Acute Stress on Performance: Implications for Health Professions Education.” Academic Medicine: Journal of the Association of American Medical Colleges 84 (Supplement): S25–33.
LeBlanc, Vicki R., and Glen W. Bandiera. 2007. “The Effects of Examination Stress on the Performance of Emergency Medicine Residents.” Medical Education 41 (6): 556–64.
LeBlanc, Vicki R., Russell D. MacDonald, Brad McArthur, Kevin King, and Tom Lepine. 2005. “Paramedic Performance in Calculating Drug Dosages Following Stressful Scenarios in a Human Patient Simulator.” Prehospital Emergency Care: Official Journal of the National Association of EMS Physicians and the National Association of State EMS Directors 9 (4): 439–44.
Leblanc, Vicki R., Cheryl Regehr, Walter Tavares, Aristathemos K. Scott, Russell Macdonald, and Kevin King. 2012. “The Impact of Stress on Paramedic Performance during Simulated Critical Events.” Prehospital and Disaster Medicine 27 (4): 369–74.
LeBlanc, Vicki, Sarah I. Woodrow, Ravi Sidhu, and Adam Dubrowski. 2008. “Examination Stress Leads to Improvements on Fundamental Technical Skills for Surgery.” American Journal of Surgery 196 (1): 114–19.
Lorello, Gianni R., Christopher M. Hicks, Sana-Ara Ahmed, Zoe Unger, Deven Chandra, and Megan A. Hayter. 2016. “Mental Practice: A Simple Tool to Enhance Team-Based Trauma Resuscitation.” CJEM 18 (2): 136–42.
Ludwig, David S. 2008. “Mindfulness in Medicine.” JAMA: The Journal of the American Medical Association 300 (11): 1350.
Mealer, Meredith, David Conrad, John Evans, Karen Jooste, Janet Solyntjes, Barbara Rothbaum, and Marc Moss. 2014. “Feasibility and Acceptability of a Resilience Training Program for Intensive Care Unit Nurses.” American Journal of Critical Care: An Official Publication, American Association of Critical-Care Nurses 23 (6): e97–105.
Meichenbaum, Donald. 1977. “Self-Instructional Training.” In Cognitive-Behavior Modification, 17–54.
Meichenbaum, Donald. 1985. Stress Inoculation Training. Pergamon Press.
Meicheribaum, Donald, and Ray Novaco. 1985. “Stress Inoculation: A Preventative Approach Donald Meicheribaum.” Issues in Mental Health Nursing 7 (1-4): 419–35.
Norris, Elizabeth M., and Andrew S. Lockey. 2012. “Human Factors in Resuscitation Teaching.” Resuscitation 83 (4): 423–27.
Petrosoniak, Andrew, and Christopher M. Hicks. 2013. “Beyond Crisis Resource Management: New Frontiers in Human Factors Training for Acute Care Medicine.” Current Opinion in Anaesthesiology 26 (6): 699–706.
Piquette, Dominique, Jordan Tarshis, Tasnim Sinuff, Robert A. Fowler, Ruxandra Pinto, and Vicki R. Leblanc. 2014. “Impact of Acute Stress on Resident Performance during Simulated Resuscitation Episodes: A Prospective Randomized Cross-over Study.” Teaching and Learning in Medicine 26 (1): 9–16.
Salas, E., M. A. Rosen, and H. King. 2007. “Managing Teams Managing Crises: Principles of Teamwork to Improve Patient Safety in the Emergency Room and beyond.” Theoretical Issues in Ergonomics Science 8 (5): 381–94.
Sanders, Charles W., Mark Sadoski, Rachel Bramson, Robert Wiprud, and Kim Van Walsum. 2004. “Comparing the Effects of Physical Practice and Mental Imagery Rehearsal on Learning Basic Surgical Skills by Medical Students.” American Journal of Obstetrics and Gynecology 191 (5): 1811–14.
Sanders, Charles W., Mark Sadoski, Kim van Walsum, Rachel Bramson, Robert Wiprud, and Theresa W. Fossum. 2008. “Learning Basic Surgical Skills with Mental Imagery: Using the Simulation Centre in the Mind.” Medical Education 42 (6): 607–12.
Saunders, T., J. E. Driskell, J. H. Johnston, and E. Salas. 1996. “The Effect of Stress Inoculation Training on Anxiety and Performance.” Journal of Occupational Health Psychology 1 (2): 170–86.
Weinberg, Robert. 2008. “Does Imagery Work? Effects on Performance and Mental Skills.” Journal of Imagery Research in Sport and Physical Activity 3 (1). doi:10.2202/1932-0191.1025.
Weisinger, Hendrie, and J. P. Pawliw-Fry. 2015. Performing Under Pressure: The Science of Doing Your Best When It Matters Most. Crown Business.
Wetzel, Cordula M., Akram George, George B. Hanna, Thanos Athanasiou, Stephen A. Black, Roger L. Kneebone, Debra Nestel, and Maria Woloshynowych. 2011. “Stress Management Training for Surgeons-a Randomized, Controlled, Intervention Study.” Annals of Surgery 253 (3): 488–94.
Whitelock, Kerry A., and Michael J. Asken. 2012. Code Calm on the Streets: Mental Toughness Skills for Pre-Hospital Emergency Personnel. Sunbury PressInc.