The first level of situational awareness involves the perception of stimuli (otherwise known as “cues”) [3]. Importantly, this requires the individual to focus their attention [5]. However, we must also realize that by focusing “here,” we risk missing “there.” In other words, we have finite attention. Because of the avalanche of stimuli, we must make conscious and unconscious decisions upon where to prioritize and what to ignore (or postpone). This can lead to fixation errors: where we focus our attention inappropriately and where we miss relevant cues. This is especially true during stress when we achieve a type of cognitive tunnel vision.

In moderation, tunnel vision lets us focus on what really matters (i.e., airway, breathing, and circulation) and eliminate what can wait (i.e., abnormal blood work). In excess, we fixate inappropriately and miss what really matters (i.e., we commit a fixation error). Examples abound but include the cardiologist who only looks for cues of myocardial ischemia and therefore misses sepsis or pulmonary embolus or the internist who misses postoperative bleeding because he looks everywhere but under the dressing. Other examples are outlined below, but readers are encouraged to think of their own examples. After all, fixation errors appear to happen to practitioners of all specialties and levels. The difference appears to be that seasoned practitioners (hopefully) know the most deadly fixations and how to mitigate them quicker [5]. Additionally, it is more likely that seasoned practitioners had previously experienced fixation errors and have learned to increase flexibility and vigilance.

For those still unconvinced about our cognitive fallibility, an excellent book by Christopher Chabris and Daniel Simons reviews their famous psychological experiment (aka “the invisible gorilla”) [8]. In brief, Simons produced a video where viewers are asked to simply count basketball passes between actors wearing white and black shirts. Given the complex things that most professions do in their daily jobs, this may seem elementary. However, regardless of seniority, typically only half are correct. This is because the others were distracted by an actor who walks into the video frame midway through. He is wearing a gorilla suit and spends 8 s pounding his chest. Typically, viewers see either the gorilla or get the number of passes correct, but rarely both. What is equally insightful is when the video is replayed, many refuse to believe that there was ever a gorilla on the original. In short, our attention is imperfect, but so is our insight. The excellent video demonstrates how we have blind spots in our vision (and in our judgment) such that we only see what we are primed to see. Our brains are prone to looking without seeing, but also to hearing without listening and to acting without truly thinking [8].

The second level of situational awareness requires synthesis and is intended to increase comprehension [3, 9]. In other words, we fuse disjointed pieces of data (e.g., chest pain, ECG changes, elevated troponin) into a recognizable model (i.e., the diagnosis of myocardial ischemia) [3, 9, 10]. By creating a cognitive model, our brains can accelerate both our understanding and our action. In other words, the model provides a short cut or “heuristic” [5, 9]. This in turn allows for pattern recognition. Ideally, recognition of a model (i.e., a diagnosis or clinical syndrome) is how prior classroom knowledge (pathophysiology, pharmacology, etc.) is retrieved and applied. Because of the importance of visual and emotional triggers, a more reliable way to unlock and apply knowledge is through situational exposure: such as realistic simulation or extensive clinical experience.

Mental models are also useful because they reduce the individual’s cognitive workload. This can free up scarce mental resources for other demands. However, once again, we need to be aware of the potential downside. Firstly, we may see patterns when they do not actually exist and are slow to recognize exceptions (i.e., we continue to rationalize a routine diagnosis by downplaying contradictory information). Secondly, all species conserve energy whenever possible. Pattern recognition and mental models make this easier. Unfortunately, subconsciously this means that we rationalize shortcuts and decreased effort. We need to be wary of our propensity to create overly simple models (so-called premature closure) when we actually need to continue searching for other explanations (e.g., the infection that fails to respond to antibiotics because it is an abscess that requires surgical drainage). We need to understand that in a crisis, vigilance and persistence are ever bit as important as traditional “cleverness.”

The other downside of our desire to reduce cognitive workload is that it can make us resistant to change. For example, the “Semmelweis effect” [11] is the reflex-like tendency to reject new evidence or knowledge because it conflicts with established norms, beliefs, or paradigms (i.e., the “new” does not fit with our current mental model). This is named after Ignaz Semmelweis who discovered neonatal mortality could be greatly decreased by hand washing. Once we understand that our behavior is more “psychological” than “logical” [5], it is easier to understand why the medical establishment rejected and even mocked his ideas.

The third level of situation awareness involves “projection,” which in turn allows the individual or team to respond proactively [6, 9, 10]. Once a mental model is created, assumptions can be shared, and this allow for anticipation and planning. For example, without even seeing a patient whom you know to have a severe head injury, you can predict that they may need airway control. Moreover, it is reasonable to assume that the patient may become hemodynamically unstable and hence will need to be where experienced staff and advanced monitoring are available. In short, this patient will either need to be in an ICU or near to one, regardless of the specifics of their case. The need for anticipation and preparation is also why another high-stakes profession, namely, the military, talks of the eight p’s of crisis management: “proper prior planning and preparation prevents piss-poor performance.” Expressed another way, “failing to prepare is akin to preparing to fail.” Regardless, it should be clear why situational awareness is one of the prime ways for individuals to safeguard the deteriorating patient; another is to maximize collective awareness by optimizing the team.

Crisis management is a team sport [5]. Therefore, we need team situational awareness. Obviously, each individual has his or her own experience and limitations. However, they must also know enough about each other’s skills and limitations in order to perform in a unified fashion. Therefore, each individual needs to not only hone their own situational awareness but also appreciate others’. Like a Venn diagram, individuals’ situational awareness must overlap in order to function together as a team [1, 9]. For example, following a trauma, as the primary survey is performed, the findings should be announced. This way all members have an equal opportunity to achieve the first level of situational awareness. Subsequently, each team member can then focus on his or her specific area. For example, the anesthetist evaluates the patient’s airway and chest regarding airway capture and ventilation. The surgeon also examines the chest, but for typical surgical interventions such as chest drains or central venous lines.