The more and more you are aware, the more and more you shed from day to day what you have learned so that your mind is always fresh, uncontaminated by previous conditioning. -Bruce Lee
Perhaps one of the most dangerous events in both military and civilian retrieval medicine is hoisting. Although relatively infrequent it is sometimes necessary to recover a sick or injured patient without landing the helicopter. Under these circumstances the patient and rescuer are lifted from the ground to a hovering aircraft using a winch system. This time of transition, while dangling from a cable one hundred feet in the air, presents substantial exposure under the most dynamic circumstances and can be wrought with hazards. You are, by necessity, moving from a point of relative instability, through a window of increased danger, to a point of relative stability. I would argue similar circumstances exist in other domains; for example, induction of anesthesia or an aircraft's period of take off or landing.
Because these events pose elevated levels of risk to the patient and rescuer, they are not undertaken without careful consideration. The danger is carefully weighed against need for expedited recovery. Furthermore, substantial effort is made to aggressively prevent and mitigate potentially catastrophic problems and complications. In addition to technical prowess and meticulous attention to detail, the role of various human factors interventions plays a key role: redundant equipment safety inspections, checklists, and standardized communication just to name a few.
One skill that permeates all aspects of the operation is situation awareness. There is, without a doubt, no substitute for active observation and processing, both consciously and subconsciously, of the continually changing environment. Colloquially, people have described this as “keeping your head on a swivel”, “watching out”, or maintaining a “heads up” orientation to what’s going on around you. Sadly, this is often where the advice and tutelage ends.
Situation awareness is a skill that can be taught, developed, and reinforced. The work of many psychologists, cognitive neuroscientists, engineers, insightful physicians, and a host of other human factors researchers has led to a deeper understanding of what situation awareness is and how we can actually measure it. When we combine this understanding with our ever-developing understanding of human behavioral science and infuse it with a practical expertise in resuscitation, we can develop novel training strategies to improve our own situation awareness and construct more effective ways of nurturing it in our colleagues.
What is Situation Awareness?
Although it may seem simple and self-explanatory, situational awareness (SA) is actually quite a bit more complicated than many people think. Situation awareness describes the cognitive skills that are involved in perception, comprehension, and anticipation of information from the surrounding environment. Dr. Mica Endsley is a brilliant engineer and pioneer in the study of SA. In her landmark paper Toward a Theory of Situation Awareness in Dynamic Systems, she formally defined situational awareness as, “the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future.”1
Across different industries including the military, NASA, commercial aviation, and medicine, poor situation awareness as been implicated as a leading cause of accidents and errors. These events have been most thoroughly documented and dissected in the aviation world.2,3 Similar findings are observed in reviewing medical mishaps in acute care: errors regularly stem from misperception and poor situation awareness.4,5,6
Endsley MR. Toward a theory of situation awareness in dynamic systems. Human Factors. 1995; 37(1): 32-64.
The widely accepted model of situational awareness, presented by Endsley, suggests that there are three phases or three “levels” to situation awareness:
Level1: the stage of perception of the elements in the current situation. It involves monitoring the surrounding environment and collecting data.
Level 2: involves the interpretation of the accumulated information. This entails a deliberate blend of analysis, pattern matching and recognition7, and the application of mental models.
Level 3: the projection of future status. Using a functional understanding of the situation, the third level applies the mental model to forecast and anticipate what will happen next. Based on this process a decision can be made and the appropriate action can be taken.8 *
(* This is a very simplistic summary of some very nuanced cognitive science. It is a somewhat incomplete, yet sufficient summary of decades of work. Please read the references, especially Situation Awareness Analysis and Measurement for a more comprehensive explanation of the theory and science involved.)
It’s important to recognize that Endsley’s model is not unidirectional or linear. SA is not static. It is cyclic. One is constantly reevaluating things and looking for clues to important changes in the system. Notice that Endsley’s model of SA may seem somewhat familiar if you’ve listened to Scott’s SMACC talk posted here: Podcast 171, Trauma, OODA Loops, and Baking Bread. If you haven’t listened to it, go check it out. Endsley has a very similar and complimentary view of the first two sections of John Boyd’s OODA loop.
There are also different types of SA. Humans have a finite working memory and attention span.9,10,11 The brain can only process so much information at a given time. Therefore, the scope of one’s situational awareness can be very broad, or can it can be narrowed to focus in on a particular task. This is referred to as global or local SA.12 Ideally, these two forms of SA are overlapping and an effective resuscitation team can employ these two types of SA together. For example, when conducting rapid sequence intubation, the person managing the airway is entirely focused on manipulating the laryngoscope, observing the airway structures, and successfully delivering the endotracheal tube into the trachea. This team member is maintaining local SA. Since it would be difficult and distracting to watch everything else going on with the patient, another team member (perhaps the one that is pushing medications) is continually scanning the patient, observing hemodynamic parameters on the monitor, watching the SpO2 and looking around for anything that may present a hazard or jeopardize first past success.
Maintaining effective and successful situation awareness is predicated on a host of dynamic factors. A loss or problem with any component part or at any point in this cognitive process could result in failure of situational awareness. Endsley has identified some problems at each level that can be identified and remedied:
|Errors Related to different levels of Situation Awareness4|
|Level 1||Level 2||Level 3|
|-Data is not available||-Lack of a mental model||-Over-reliance on a mental model|
|-Data is difficult to detect||-Inadequate/poor mental model||-Not realizing a mental model must change|
|-Failure to scan or observe data||-Over-reliance on default model|
|-Misinterpritation of data||-Memory failure|
Measuring Situation Awareness
It is important to note that much work has been done in order to quantify and measure situation awareness. These attempts have been transformative and helpful in several important ways. First, continually trying to measure SA has provided a deeper understanding of what it really is and allowed better description its component parts. It has also improved the design of equipment across many domains and facilitated better alignment between new technologies and human cognitive processes. Finally, and perhaps most germane to this discussion, it has proved useful in quantifying individuals’ levels of SA and providing important ways to measure the effectiveness of various training interventions on improving SA.12
One of the earliest metrics of measuring SA was developed by Endsley in 1988. It is called the Situation Awareness Global Assessment Technique (SAGAT).13 This tool has been used in diverse fields such as aviation, air traffic control, driving, and, nuclear power plant operation, and medical simulation.14 Another rating system is called the Situation Awareness Rating Scale (SARS). This tool is used by observers to rate a team’s or an individual’s level of SA. It is important to point out that these tools really evaluate surrogates of SA. Since SA is truly and internal, cognitive process it can only be objectively measured by looking for markers that someone is processing information observed from the environment around them by taking certain actions or communicating certain pieces of information.
Situational awareness has also been included in other quantitative tools that evaluate team performance. The anesthesia world has been at the forefront of simulation, crisis resource management, and evaluating non-technical skills in medicine, including SA. Starting with the ground-breaking and prolific work of Dr. David Gaba in the late 1980s, anesthesia developed a number of modalities for measuring and teaching non-technical skills.15,16,17 The primary thrust of their work was the laudable effort to introduce a comprehensive Crisis Resource Management training program to the specialty: Anesthesia Crisis Resource Management (ACRM).18
This approach has been extended to a wide variety of other health care specialties that involve complexity, high acuity, and time sensitive decisions, such as emergency medicine, trauma, critical care, and rapid response teams. In 2003, Fletcher et al introduced the Anaesthetists’ Non-Technical Skills (ANTS) rating system. This validated, reliable tool helped assess anesthetists’ performance and specifically evaluated aspects of situation awareness such as, “Gathering information, recognizing and understanding problems, anticipating, and re-evaluating.” Other systems have been developed for surgeons, such as the Non-Technical Skills for Surgeons (NOTSS) behavioral rating system20, and also include evaluation of an individual’s situation awareness capabilities.
In addition to evaluating individual non-technical skills, recent developments have looked closer at evaluating team performance in medicine. A number of validated tools have been designed both for practical administration and strict research purposes to rate a team’s performance. Interesting enough, they all include metrics for evaluating situation awareness. The Team Emergency Assessment Measure (TEAM) specifically asks if the team “monitored and reassessed the situation”, “anticipated potential situations”, and if the team leader “maintained a global perspective.”21,22 The Mayo High Performance Teamwork Scale includes items that evaluate how team members “call attention to actions that they feel could cause errors or complications” as well as acknowledging statements “directed at avoiding or containing errors or seeking clarification.”23
Building Situation Awareness
Most academic endeavors have done well to describe SA, unveil the neuroscience behind the limitations of human awareness, identify factors that degrade SA, and even quantify SA. However, when it comes to specific suggestions on how to improve SA, the literature is lacking. Some recommendations have been made based on the available evidence regarding what to add to the training. This provides some material to start working with.
Some excellent work has been done in the ergonomics literature as it pertains to information display and its interplay with SA in anesthesia.24,25 However, broad and universal improvements in resuscitation SA have to transcend technology that is isolated to the OR or other procedural areas in large tertiary care centers. They should, ideally, have applicability outside the hospital or in resource-limited facilities. The goal, therefore, would be to develop cognitive and behavioral tools that we can incorporate into our current practice and training paradigms across a host of procedures and situations. It’s rather unfulfilling when the extent of recommendations is “make people aware of how SA works”, “explain to them what causes us to lose SA”, and “tell them to be aware of what’s going on.”
As many authors have identified our cognitive capacity to recall information, make decisions, and maintain attention is degraded by acute stress, something we often experience in resuscitation. A potential solution to this problem entails two primary components:
- Build active cognitive and behavioral systems of awareness
- Turn an active system of awareness into an unconscious habit.
So…how, precisely, can we accomplish these objectives? Stay tuned for Part 2 where I discuss the cognitive science behind developing active systems of situation awareness as powerful habits in resuscitation.
- Endsley MR. Toward a Theory of Situation Awareness in Dynamic Systems. Human Factors: The Journal of the Human Factors and Ergonomics Society. 1995;37(1):32-64.
- Flin R, O’Connor P, Crichton M. Safety at the Sharp End: A Guide to Non-Technical Skills. Aldershot, England?; Burlington, VT: Ashgate Publishing; 2008.
- Endsley M. A taxonomy of situation awareness errors. In: Fuller R, Johnson N, and McDonald N (Eds.). Human Factors in Aviation Operations. Aldershot: Avebury. 1995.
- Way LW, Stewart L, Gantert W, et al. Causes and Prevention of Laparoscopic Bile Duct Injuries. Ann Surg. 2003;237(4):460-469.
- Endsley M. A taxonomy of situation awareness errors. In Fuller R, Johnson N, and McDonald N (Eds.). Human Factors in Aviation Operations. Aldershot: Avebury. 1995.
- Risser DT, Rice MM, Salisbury ML, Simon R, Jay GD, Berns SD. The Potential for Improved Teamwork to Reduce Medical Errors in the Emergency Department. Annals of Emergency Medicine. 1999;34(3):373-383. doi:10.1016/S0196-0644(99)70134-4.
- Zsambok CE, Klein G. Naturalistic Decision Making. Psychology Press; 2014.
- Endsley MR. Toward a Theory of Situation Awareness in Dynamic Systems. Human Factors: The Journal of the Human Factors and Ergonomics Society. 1995;37(1):32-64.
- Endsley MR, Smith RP. Attention Distribution and Decision Making in Tactical Air Combat. Human Factors: The Journal of the Human Factors and Ergonomics Society. 1996;38(2):232-249.
- Endsley MR, Farley TC, Jones WM, Midkiff AH, Hansman RJ. Situation Awareness Information Requirements For Commercial Airline Pilots. International Center for Air Transportation; 1998. http://dspace.mit.edu/handle/1721.1/35929. Accessed April 4, 2016.
- Endsley MR, Smolensky MW. Situation awareness in air traffic control: The picture. In: Smolensky MW, Stein ES, eds. Human Factors in Air Traffic Control. San Diego, CA, US: Academic Press; 1998:115-154.
- Endsley MR, Garland DJ. Situation Awareness Analysis and Measurement. CRC Press; 2000.
- Endsley MR. Situation awareness global assessment technique (SAGAT). In: Aerospace and Electronics Conference, 1988. NAECON 1988. Proceedings of the IEEE 1988 National; 1988:789-795.
- Wright MC, Taekman JM, Endsley MR. Objective measures of situation awareness in a simulated medical environment. Qual Saf Health Care. 2004;13(suppl 1):i65-i71.
- Gaba DM, DeAnda A. A comprehensive anesthesia simulation environment: re-creating the operating room for research and training. Anesthesiology. 1988 Sep;69(3):387-94.
- Howard SK, Gaba DM, Fish KJ, Yang G, Sarnquist FH. Anesthesia crisis resource management training: teaching anesthesiologists to handle critical incidents. Aviation, space, and environmental medicine. 1992 Sep;63(9):763-70.
- Holzman RS, Cooper JB, Gaba DM, Philip JH, Small SD, Feinstem D. Anesthesia crisis resource management: real-life simulation training in operating room crises. Journal of clinical anesthesia. 1995 Dec 31;7(8):675-87.
- Gaba DM, Howard SK, Fish KJ, Smith BE, Sowb YA. Simulation-based training in anesthesia crisis resource management (ACRM): a decade of experience. Simulation & Gaming. 2001 Jun 1;32(2):175-93.
- Fletcher G, Flin R, McGeorge P, Glavin R, Maran N, Patey R. Anaesthetists’ Non?Technical Skills (ANTS): evaluation of a behavioural marker system†. British journal of anaesthesia. 2003 May 1;90(5):580-8.
- Yule S, Flin R, Maran N, Rowley D, Youngson G, Paterson-Brown S. Surgeons’ non-technical skills in the operating room: reliability testing of the NOTSS behavior rating system. World journal of surgery. 2008 Apr 1;32(4):548-56.
- Cooper S, Cant R, Porter J, Sellick K, Somers G, Kinsman L, Nestel D. Rating medical emergency teamwork performance: development of the Team Emergency Assessment Measure (TEAM). Resuscitation. 2010 Apr 30;81(4):446-52.
- Cooper SJ, Cant RP. Measuring non-technical skills of medical emergency teams: An update on the validity and reliability of the Team Emergency Assessment Measure. Resuscitation. 2014 Jan 31;85(1):31-3.
- Malec JF, Torsher LC, Dunn WF, Wiegmann DA, Arnold JJ, Brown DA, Phatak V. The mayo high performance teamwork scale: reliability and validity for evaluating key crew resource management skills. Simulation in Healthcare. 2007 Apr 1;2(1):4-10.
- Zhang Y, Drews FA, Westenskow DR, et al. Effects of Integrated Graphical Displays on Situation Awareness in Anaesthesiology. Cognition Tech Work. 4(2):82-90.
- Ford S, Daniels J, Lim J, et al. A novel vibrotactile display to improve the performance of anesthesiologists in a simulated critical incident. Anesth Analg. 2008;106(4):1182-1188.