Observation

Anesthesia professionals use observations to decide whether the patient’s course is on track or whether a problem is occurring; this is the first step of the decision making cycle. Data are observed and transformed by interpretation into information, followed by further interpretation into meaning. Data streams typically involve direct visual, auditory, or tactile contact with the patient, the surgical field, routine electronic monitoring, special (sometimes invasive) monitoring systems, contents of suction canisters and sponges, reading of reports of laboratory test results, and communications from other personnel. Loeb showed that anesthesiologists typically observe monitors for approximately 1 to 2 seconds every 10 to 20 seconds and that it usually took several observing cycles before they detected a subtle cue on the monitor. Management of rapidly changing situations requires the anesthesia professional to assess a wide variety of information sources. Because the human mind can attend closely to only one or two items at a time, the anesthesia professional’s supervisory control level must decide what information to attend to and how frequently to observe it (as later shown at CRM key point 14 “Allocate attention wisely”). Constant observation and interpretation of the different information systems is executed repeatedly throughout the course of an anesthetic regimen. The plethora of simultaneous data streams in even the most routine cases is a challenge. Vigilance, defined as the capacity to sustain attention, plays a crucial role in the observation and detection of problems and is a necessary prerequisite for meaningful care. Vigilance can be degraded by performance-shaping factors (see later section “Performance Shaping Factors”) and it can be overwhelmed by the sheer amount of information and the rapidity with which it is changing.

Verification

In the working environment of an anesthesia professional, the available, observed information is not always reliable. Most monitoring is noninvasive and indirect and is susceptible to artifacts (false data). Even direct clinical observations such as vision or auscultation can be ambiguous. Brief transients (true data of short duration) can occur that quickly correct themselves. To prevent them from skewing the decision making process and triggering precipitous actions that may have significant side effects, critical observations must be verified before the clinician can act on them. This requires the use of all available data and information and cross-checking different related data streams rather than depending solely on any single datum without sensible interpretation (as later shown in CRM key point 8 “Use all available information” and CRM key point 10 “Cross check and double check; never assume anything”). Verification uses a variety of methods, shown in Table 6.2 .

Problem Recognition

Having recognized a problem, how does the expert anesthesia professional respond? The classical paradigm of decision making involves a careful comparison of the evidence with various causal hypotheses that could explain the problem. This is followed by a careful analysis of all possible actions and solutions. This approach, although powerful, is relatively slow and does not work well with ambiguous or scanty evidence. Many perioperative problems faced by anesthesia professionals require quick action under uncertainty to prevent a rapid cascade to a catastrophic adverse outcome, and solution of these problems through formal deductive reasoning from first principles is just too slow. The process of problem recognition is a central feature of several theories of cognition in complex, dynamic worlds. Problem recognition involves matching sets of environmental cues to patterns that are known to represent specific types of problems. Given the high uncertainty seen in anesthesia, the available information sources cannot always disclose the existence of a problem, and even if they do, they may not specify its identity or origin. Anesthesia professionals use approximation strategies to handle these ambiguous situations; psychologists term such strategies heuristics . Stiegler and Tung give a detailed review of heuristics and other biases that affect problem recognition. One heuristic is to categorize what is happening as one of several generic problems, each of which encompasses many different underlying conditions (similarity/pattern matching). Another is to gamble on a single diagnosis (frequency gambling ) by initially choosing the single most frequent candidate event. During preoperative planning, the anesthesia professional may adjust a mental “index of suspicion” for recognizing certain specific problems anticipated for that particular patient or surgical procedure. The anesthesia professional must also decide whether a single underlying diagnosis explains all the data or whether they could come from multiple causes. This decision is important because excessive attempts to refine the diagnosis can be very costly in terms of allocation of attention. By contrast, a premature diagnosis can lead to inadequate or erroneous treatment. The use of heuristics is typical of expert anesthesia professionals and often results in considerable time savings in dealing with problems. However, it is a double-edged sword. Both frequency gambling and inappropriate allocation of attention solely to expected problems can seriously undermine problem solving when these gambles do not pay off or are not corrected in the reevaluation process.

Many of the issues that are related to problem recognition and cognition in general are discussed in more detail in the section on decision making further below, especially when dealing with the models of System I thinking and System II thinking and of recognition-primed decision making.

Prediction of Future States

Problems must be assessed in terms of their significance for the future states of the patient. Predicting future states based on the occurrence of seemingly trivial problems is a major part of the anticipatory behaviors that characterize expert crisis managers. Problems that are already critical or that can be predicted to evolve into critical incidents receive the highest priority (as later shown in CRM key point 15 “Set priorities dynamically”). Prediction of future states also influences action planning by defining the timeframe available for required actions. Cook and colleagues described “going sour” incidents in which the future state of the patient was not adequately taken into account when early manifestations of problems were apparent. One of the challenges known from research in psychology is that the human mind is not very well suited to predict future states, when things are changing in a nonlinear fashion. Under such circumstances, which are common for natural systems such as the human body, the rate of change is almost invariably underestimated, and people are surprised at the outcome.

Precompiled Responses

Once a critical event has been observed and verified the anesthesia professional needs to respond. In complex, dynamic domains, the initial responses of experts to the majority of events stem from precompiled rules or response plans for dealing with a recognized event. This method is referred to as recognition-primed decision making, because once the event is identified, the response is well known (see later section “Decision Making”). In the anesthesia domain, these responses are usually acquired through personal experience alone, although there is a growing realization that critical response protocols must be codified explicitly and taught systematically. Experienced anesthesia professionals have been observed to rearrange, recompile, and rehearse these responses mentally based on the patient’s condition, the surgical procedure, and the problems to be expected. Ideally, precompiled responses to common problems are retrieved appropriately and executed rapidly. When the exact nature of the problem is not apparent, a set of generic responses appropriate to the overall situation may be invoked. For example, if a problem with ventilation is detected, the anesthesia professional may switch to manual ventilation at a higher fraction of inspired oxygen (FiO ₂ ) while considering further diagnostic actions. However, experiments involving simulation have demonstrated that even experienced anesthesia professionals show great variability in their use of response procedures to critical situations. This finding led these investigators to target simulator-based training in the systematic training of responses to critical events.

Even the ideal use of precompiled responses is destined to fail when the problem does not have the suspected cause or when it does not respond to the usual actions. Anesthesia cannot be administered purely by precompiled “cookbook” procedures. Abstract reasoning about the problem through the use of fundamental medical knowledge still takes place in parallel with precompiled responses, even when quick action must be taken. This seems to involve a search for high-level analogies or true deductive reasoning using deep medical and technical knowledge and a thorough analysis of all possible solutions. Anesthesia professionals managing simulated crises have linked their precompiled actions to abstract medical concepts.

Taking Action/Action Implementation

Anesthesiologists need to share their attention among different cognitive levels, among tasks, and often among problems. The intensive demands on the anesthesia professional’s attention could easily swamp the available mental resources. Therefore, the anesthesia professional must strike a balance between acting quickly on every small perturbation (which requires a lot of attention) and adopting a more conservative “wait-and-see” attitude. This balance must be constantly shifted between these extremes as the situation changes. However, during simulated crisis situations, some practitioners showed great reluctance to switch from business as usual to emergency mode even when serious problems were detected. Erring too far in the direction of wait and see is an error that can be particularly catastrophic. Preparedness for active intervention in case of dynamically changing events is a key element of an anesthesiologist’s work. But how frequent is this requirement? According to the review of Wacker and Staender, adverse events in the perioperative period continue to be frequent, occur in about 30% of hospital admissions, and may be preventable in more than 50%.

At any time during an anesthetic regimen there may be multiple things to do, each of which is intrinsically appropriate, yet they cannot all be done at once. Simulation experiments have shown that anesthesia professionals sometimes have difficulty selecting, planning, and scheduling actions optimally.

A particular hallmark of anesthesiology is that the decision maker does not just decide what action is required but is often involved directly in the implementation of actions. Executing these actions requires substantial attention and may in fact impair the anesthesia professional’s mental and physical ability to perform other activities (e.g., when an action requires a sterile procedure). This is particularly an issue when other tasks have been interrupted or temporarily suspended. Prospective memory, one’s ability to remember in the future to perform an action (i.e., to complete a task) can be easily disrupted. In addition, anesthesia professionals engaged in a manual procedure are strongly constrained from performing other manual tasks or from maintaining awareness of incoming information.

Reevaluation

In order to successfully solve dynamic problems and to cope with the rapid changes and profound diagnostic and therapeutic uncertainties seen during anesthesia, the core process must include repetitive reevaluation of the situation. Thus, the reevaluation step, initiated by the supervisory control level, returns the anesthesia professional to the observation phase, but with specific assessments in mind (see also CRM key point 12, “Reevaluate repeatedly”). Only by frequently reassessing the situation can the anesthesia professional adapt to dynamic processes, since the initial diagnosis and situation assessment can be incorrect. Even actions that are appropriate to the problem are not always successful.

The process of continually updating the assessment of the situation and monitoring the efficacy of chosen actions is termed situation awareness . Situation awareness is a very interesting and important topic in analyzing performance and reasons for errors and is discussed in detail in a later section. Box 6.2 gives examples of reevaluation questions in order to maintain situation awareness.

Faulty reevaluation, inadequate adaptation of the plan, or loss of situation awareness can result in a type of human error termed fixation error . Fixation errors have been described in responses of professionals to abnormal situations. Avoiding and recognizing fixation errors in the field of anesthesia is covered more in detail in section “Introduction of the 15 Crisis Resource Management Key Principles.”

Supervisory Control

The supervisory control allocates the scarce resource of attention during multitasking, and oversees and modulates the core process. For example, determining the frequency of observation of different data streams, prioritizing diagnostic and therapeutic alternatives, actively managing workload, prioritizing and scheduling actions. Supervisory control actively manages the workload by (1) avoiding high-workload situations by anticipation and planning, (2) distributing workload over time or (3) over personnel, (4) changing the nature of the task to reduce work, or (5) minimizing distraction. More details regarding the active management of workload are touched on in the later section on CRM key point 5 “Distribute the Workload.”

Resource Management

The highest layer of metacognition and control is known as resource management—the ability to command and control all the resources at hand to care for the patient and to respond to problems. This involves translating the knowledge of what needs to be done into effective team activity by taking into account the limitations of the complex and often ill-structured perioperative domain. Resources include personnel, equipment, and supplies, both in the immediate vicinity and, when necessary, throughout the various levels of the organization. Resource management explicitly demands teamwork and crew coordination. It is not enough for the anesthesia professional to know what to do or even to be able to do each task alone. Only so much can be accomplished in a given time, and some tasks can be performed only by other skilled personnel (e.g., catheterization lab). A key responsibility of the anesthesia professional is to mobilize needed resources and to distribute the relevant goals and tasks among those available. The details of this critical function are described in the section on “Crisis Resource Management.”

Primary Task Performance

The primary task performance measure assesses the subject’s performance on standard work tasks (e.g., cases seen, knots tied, etc.) as they are made progressively more difficult by increasing the number of tasks, task density, or task complexity. At first, the subject is able to keep up with the increasing task load, but at some point, the workload exceeds the ability to manage it, and performance on the standard tasks decreases.

Secondary Task Probing

Secondary task probing tests the subject with a minimally intrusive secondary task that is added to the primary work tasks. The secondary task is a simple one for which performance can be objectively measured. Reaction time, finger tapping, mental arithmetic and a vibrotactile device have for example been used for this technique as a secondary task. The anesthesia professional is instructed that the primary tasks of patient care take absolute precedence over the secondary task. Therefore, assuming that the secondary task requires some of the same mental resources as the primary task, the performance of the anesthesiologist on the secondary task is an indirect reflection of the spare capacity available to deal with it: the greater the spare capacity, the lower the primary workload. Depending on the secondary task response channels (manual, voice, gesture, multiple ways) there can exist channel interference. Controversy exists about whether these probes measure “vigilance” or “workload,” although the same techniques probably measure both aspects of performance. When probes occur infrequently, are subtle, have multiple response channels, and are performed with a low level of existing workload, they are more likely to measure vigilance; when they are frequent, readily detectable, require a manual response, and are performed during a high-workload period, they probably are more indicative of spare capacity and workload.

Subjective Measures

In subjective measures, individuals are asked, most commonly in retrospect but sometimes in real time, how much load they were or are under during actual work situations. A common and validated form to assess subjective workload is the NASA TLX form. Subjective measures usually complement objective measurements of external observations, since an anesthesia professional may subjectively underestimate the workload in settings in which objective measurements demonstrate a marked reduction in spare capacity.

Physiologic Measures

The final set of techniques for assessing workload consists of physiologic measures. Visual or auditory evoked potentials have been used successfully to assess mental workload, but this technique can be used only in a static laboratory environment. Heart rate (especially certain aspects of heart rate variability) and blood pressure are other physiologic measures that have been used, but there are challenges in reliable interpretation.

Teaching

Close interaction of experienced anesthesia professionals with inexperienced clinical trainees during actual surgical procedures is a standard approach to training. It can be hypothesized that teaching adds to the workload of the more experienced care provider who is simultaneously responsible for safe and efficient anesthesia care during the procedure. Weinger and co-workers found that teaching teams, involving one-to-one supervision of fourth-year medical students or first-month anesthesia residents by an attending anesthesiologist, had significantly slower response times to a warning light than non-teaching teams of attending(s) of similar experience. Response latency was highest during induction and emergence. This vigilance test was also a procedural (performance) workload assessment measure indicating increased workload and reduced spare capacity. They also found that workload density was significantly increased for teaching as opposed to non-teaching teams. In sum, intraoperative teaching increased workload and decreased vigilance, suggesting the need for caution when educating during patient care.

Delegation and Supervision

Experience suggests that the effect of delegation on workload varies depending on the nature of the task and how confident the delegating anesthesia professional feels about the capability of the person to whom the task is assigned. Delegation must be guided by the supervisor’s situation awareness and overall ability to process information on the patients’ condition. Several further aspects are presented in the work of Leedal and Smith.

Routine Events

Novice trainee anesthesia professionals were found to perform many of the same tasks as do more experienced personnel at specific phases of an anesthetic regimen, but take longer over tasks, show longer latency of response, and greater task workload than third-year trainees and experienced nurse anesthetists. While task density was generally highest for both subject groups in the period up to, during, and immediately after intubation, the more experienced trainees had higher task densities than the novices, suggesting greater competence among the former in carrying out multiple tasks in a short period of time. Those findings are in line with other studies, including the study of Weinger and associates that evaluated the mean response time of pressing a buzzer at the flashing of a red light (secondary task). The response time was markedly less than 60 seconds for experienced subjects in both the induction and post induction (maintenance) phases, but it was much higher for novice residents during the induction phase. One explanation for those findings may be that the reduction of workload depends partly on the degree to which tasks can become routine, thus freeing mental resources for other tasks. Leedal and Smith conclude concerning this matter in their review: “Experienced staff appear to show ‘spare capacity’ in performance during routine cases, which we suggest allows them an attentional ‘safety margin’ should adverse events occur ” (p. 708)

In contrast, a more recent study presented by Byrne and co-workers found there was limited evidence of a relationship between workload and experience.

Another recent finding indicates that more experienced anesthesia teams may be more likely to attempt to coordinate implicitly, without much overt communication, which makes them more reliant on accurate and shared understandings of the task and their teamwork.

Novice residents also spent more time speaking to their attending staff (11% of preintubation time) than did experienced residents or CRNAs. Experienced personnel observed the surgical field more than did the novices. Novices did take longer to complete patient preparation and induction of anesthesia, but it appeared that some of the extra time taken by novices working under supervision was offset by the efficiency of offloading other concurrent tasks to the attending anesthesiologist such that preintubation time was increased by only 6 minutes for novices.

Critical Events/Emergencies

Schulz and colleagues presented data where more experienced anesthetists (>2 years work experience) increased the amount of time dedicated to manual tasks from 21% to 25% during critical incidents, whereas the less experienced decreased from 20% to 14%. The less experienced anesthesia providers spend more time on monitoring tasks.

A study by Byrne and Jones looked at differences in the performance of experienced and less experienced anesthesia professionals during 180 simulated anesthesia emergency scenarios. The results showed significant differences only between the first and second year. As seen in other studies, significant errors occurred at all levels of experience, and most of the anesthesia professionals deviated from established guidelines.

A classic simulation study by DeAnda and Gaba investigated the response of anesthesia trainees and experienced anesthesia faculty and private practitioners to six preplanned critical incidents of differing type and severity. The incidents included (1) endobronchial intubation (EI) resulting from surgical manipulation of the tube; (2) occlusion of intravenous (IV) tubing; (3) atrial fibrillation (AF) with a rapid ventricular response and hypotension; (4) airway disconnection between the endotracheal tube and the breathing circuit; (5) breathing hoses too short to turn the table 180 degrees, as requested by the surgeon; and (6) ventricular tachycardia or fibrillation. For each incident, considerable interindividual variability was found in detection and correction times, in information sources used, and in actions taken. The average performance of the anesthesia professionals tended to improve with experience, although this varied by incident. The performance of the experienced groups was not better than that of the second-year residents (who were in their final year of training at that time). Many (but not all) novice residents performed indistinguishably from more experienced subjects. Each experience group contained some who required excessive time to solve the problem or who never solved it. In each experience group at least one individual made major errors that could have had a substantial negative impact on a patient’s clinical outcome. For example, one faculty member never used electrical countershock to treat ventricular fibrillation. One private practitioner treated the EI as though it were “bronchospasm” and never assessed the symmetry of ventilation. One resident never found the airway disconnection. The elements of suboptimal performance were both technical and cognitive. Technical problems included choosing defibrillation energies appropriate for internal paddles when using external paddles, ampule swap, and failure to inflate the endotracheal tube cuff that resulted in a leak. Cognitive problems included failure to allocate attention to the most critical problems and fixation errors.

Schwid and O’Donnell performed an experiment similar to those of DeAnda and Gaba and received similar results. After working on several practice cases without critical incidents, each subject was asked to manage 3 or 4 cases involving a total of 4 serious critical events (esophageal intubation, myocardial ischemia, anaphylaxis, and cardiac arrest). The anesthesiologists studied had varying experience levels. Significant errors in diagnosis or treatment were made in every experience group. The errors occurred in both diagnosis of problems and in deciding on and implementing appropriate treatment. For example, 60% of subjects did not make the diagnosis of anaphylaxis despite available information on heart rate, blood pressure, wheezing, increased peak inspiratory pressure, and the presence of a rash. In managing myocardial ischemia, multiple failures occurred. 30% of subjects did not compensate for severe abnormalities while considering diagnostic maneuvers. Fixation errors in which initial diagnoses and plans were never revised were frequent, even when they were clearly wrong.

Independent from professionals’ experience, Howard and colleagues found a substantial incidence of difficulties during simulated emergencies: managing multiple problems simultaneously, applying attention to the most critical needs, acting as team leader, communicating with personnel, and using all available OR resources to best advantage. Analysis of videotaped trauma and resuscitation cases has revealed inadequacies in the availability and arrangement of monitoring equipment, as well as nonexistent or ambiguous communication. Byrne and Jones evaluated the performance of anesthetists during nine emergency cases, showing that serious errors in both diagnosis and treatment were made and accepted treatment guidelines were not followed. Diagnosis of several common critical incidents, for example, anaphylaxis, was hard to name. As described earlier, once diagnosed, no structured plans or algorithms were used.

These classic studies date back 25 years or more, yet the most recent studies remain completely consistent with older studies. In the 2017 Weinger and colleagues publication, a total of 263 consenting U.S. board-certified anesthesiologists (BCAs—i.e., physicians) participated in two, 20-minute, standardized, high-fidelity simulation scenarios of unanticipated acute events during existing Maintenance of Certification in Anesthesiology simulation courses. The scenarios were from among the following: (1) local anesthetic systemic toxicity with hemodynamic collapse; (2) hemorrhagic shock due to hidden retroperitoneal bleeding during laparoscopy; (3) malignant hyperthermia presenting in the postanesthesia care unit; and (4) acute onset of AF with hemodynamic instability during laparotomy followed by ST elevation myocardial infarction. Performance measurement rubrics were established in advance: a scoresheet of critical clinical performance elements, behavioral anchored ordinal scales of four nontechnical skills, ordinal scales for overall individual and team technical performance and nontechnical performance, and a binary rating as to whether performance met or exceeded that expected of a BCA. The results showed that critical clinical performance elements were commonly omitted, roughly in four broad areas of crisis management, failures to: (1) escalate therapy where first-line options did not work (e.g., using epinephrine or vasopressin when phenylephrine, ephedrine, or fluids did not sufficiently correct hypotension); (2) use available resources (e.g., calling for help when conditions have deteriorated appreciably); (3) speak up and engage other team members, especially when action by them was required (e.g., asking the surgeon to change the surgical approach when it is essential to effective treatment); and (4) follow evidence-based guidelines (e.g., giving dantrolene to a patient with obvious MH). The performance of approximately 25% of subjects was rated in the low portion of the various technical and nontechnical 9-point ordinal scales. In about 30% of encounters, performance was rated as “below the level expected of a BCA.”

Different Components of Human Factors

Derived from the SEIPS model and adapted by the authors, different components of HF are:

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  the behavior of individuals and their behavior/knowledge in regard to tasks (individual level)

  
  
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  the interactions with each other (team level)

  
  
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  the interactions of professionals with the organizational/sociocultural conditions (organizational level)

  
  
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  the interactions of professionals with the environment/workspace (environmental level) and

  
  
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  the interactions of professionals with technology/equipment (technology/engineering/design level)

Those five human factor components are necessary and sufficient to describe and understand the anesthesia professional’s entire work system from a HF perspective. The components interact with and influence each other, resulting in a large number of relationships between different levels. At times the components compensate each other (e.g., when professionals work faster to compensate for time pressure or when people collaborate to solve problems that are beyond an individual’s abilities). Other times the components resonate with each other and amplify their effects—for the good (e.g., having the right equipment for the task at hand) or the bad (e.g., lacking resources to solve a problem). Given that this chapter cannot deal with human factors in a comprehensive way, many topics can be touched on only briefly. Although the environmental and technology levels can be important—cognition is challenged when there is a power failure or a breakdown of key clinical equipment—in this chapter the focus lies on the most important aspects of human factors directly relevant to anesthesia professionals: the individual level, team level, and organizational level.

Different Ways to Categorize NonTechnical Skills

In general, NTS can be categorized into two broad areas: (1) cognitive and mental skills on the individual level, including decision making and situation awareness; and (2) social and interpersonal skills on the team level, including teamwork, communication, and leadership. Commercial aviation incorporated such nontechnical skills in the cockpit (later crew) resource management paradigm (CRM, 1980s and continuous later evolution) and the “NOTECHS” paradigm in the late 1990s. In anesthesiology, the anesthesia crisis resource management (ACRM) framework was introduced by Howard and co-workers in 1990 as an adaptation of aviation’s CRM. The ACRM approach categorizes NTS based on the five key elements of communication, situation awareness, decision making, teamwork (implicitly including leadership), and task management ( Fig. 6.5 ). The anesthesia nontechnical skills (ANTS) framework by Fletcher and colleagues was introduced in 2003; Flin and colleagues give an overview of its history, development, application, use, and emerging is issues. ^, The ANTS approach typically includes the four categories of situation awareness, decision making, teamwork (explicitly including leadership), and task management. Neither of these frameworks, and indeed no usable paradigm, can capture explicitly every important aspect of HF applied to anesthesiology. For example the management of the performance-shaping factors stress and fatigue are also part of the ANTS framework, but are implicit in ACRM. Communication itself is not an explicit skill element of the ANTS framework (which assumes that communication pervades each element), whereas in ACRM it is a specific skill that needs explicit mention and training. Of note, from their start in anesthesiology, nontechnical skills frameworks have been further adapted to several other medical fields, such as for surgeons and intensive care specialists.

The five main elements of Crisis Resource Management (CRM).

The main elements include: Communication, situation awareness, decision making, task management, and teamwork. In this approach, effective communication is like the glue that holds all the other components together. Besides, all the components are intertwined with and related to each other, indicated by the arrows between the elements.

Assessment of NonTechnical Skills

In response to the growing acceptance of human factors and nontechnical skills influencing medical performance, several rubrics to measure NTS have been developed. Gaba and colleagues in 1998 described the direct adaptation for assessment of NTS of a set of CRM-anchored ordinal scale markers from Helmreich et al. concerning aviation. In 2004 the ANTS framework was complemented by a behaviorally anchored rating scale in 2004. A new set of assessment scales for four markers of NTS was introduced by Weinger and colleagues in 2017 based on the fusion of aspects of a number of prior approaches.

A further, rather new approach for the assessment of nontechnical skills is the Co-ACT framework described by Kolbe and co-workers. The framework serves observing coordination behavior, especially in acute care teams like anesthesia, and consists of four categories, each category obtaining three further subelements that more specifically describe the NTS: (1) explicit action coordination with the elements instruction, speaking up , and planning ; (2) implicit action coordination with the elements monitoring , talking to the room (action-related), and providing assistance ; (3) explicit information coordination with the elements information request , information evaluation , and information upon request ; and (4) implicit information coordination with the elements gathering information, talking to the room (information-related), and information without request .

Challenges of the Assessment of NonTechnical Skills

The psychometric qualities of measuring NTS have been assessed by the developers of the ANTS system and were considered to be of acceptable level, whereas another study assessed the reliability after a 1-day training for raters and concluded that reliability was poor. A study from Denmark showed good psychometric qualities. Originally developed for educational purposes and used to discuss the NTS of anesthesiologists after training sessions in order to improve in NTS, Zwaan and colleagues assessed the usability and reliability for ANTS in research, finding that the ANTS system was reliable for the total score and usable to measure physicians’ NTS in a research setting. However, the investigators found a variation between the reliability of the different elements and recommend excluding elements in advance that are not applicable or observable in the situation of interest. It might not always be easy, however, to identify those elements that should be excluded. On the whole, the ANTS system appears to be a useful tool to enhance assessment of nontechnical skills in anesthesia and other medical fields further, and its careful derivation from an established system of nontechnical assessment in aviation (NOTECHS) may even allow some interdomain comparisons. However, more recently Watkins and colleagues directly compared ANTS with the system used in the Weinger and colleagues 2017 paper and showed that ANTS was more difficult to use but that the two systems otherwise achieved equivalent assessment results.

NonTechnical Skills: The Bad – The Good – The Variable

Good nontechnical skills (i.e., vigilance, efficient communication, team coordination, etc.) reduce the likelihood of active and passive errors and adverse events, and also increase human performance, whereas suboptimal NTS are expected to do the reverse. These effects are variable; for example, a person may communicate very effectively in one instance and fail to do so in the next challenging communication role.

A study from Denmark investigated the relationship between technical and nontechnical skills. Twenty-five video recordings of second-year anesthesiologists managing a simulated difficult airway management scenario were rated with the ANTS instrument and a score for the technical aspect for the procedure. In addition, written descriptions of the NTS performance were collected and content analyzed. The correlation between the two scores was not significant, but the content analysis comparing the NTS description in the best and poorest three scenarios identified what contributed most to good NTS. These were systematically collecting information, thinking ahead, communicating and justifying of decisions, delegating tasks, and vigilantly responding to the evolving situation. Poor NTS were related to: lack of structured approach, lack of articulating plans and decisions, poor resource and task management, lack of considering consequences of treatment, poor response to the evolving situation, and lack of leadership.

What is the Impact of Non-Technical Skills and Human Factors on Poor Performance in Medicine?

The impact of poor NTS on poor human performance in the medical field cannot be overestimated. Depending on the literature, it is estimated that up to 80% of all errors in medicine can be attributed to problems with NTS and human factors.

Even though one can argue on the one hand that due to progress in technology the findings and estimates of the pioneer study of Cooper and colleagues performed in 1978 (results relating up to 80% of incidents to human factors) have been outdated for a long time, on the other hand those figures are (1) comparable to findings in other dynamic and complex work environments and (2) newer studies as recent as 2015 still reconfirm those findings (references see below). In the following some illustrative studies are mentioned that link HF and safety challenges.

In 1993 an analysis of 2000 incident reports from the Australian Incident Reporting Study took place, investigating the incidents for relations to human factors and NTS. In 83% of incidents, human factor elements were scored by the reporters. Even though scoring by the incident reporters might not produce results as accurate as those of a systematic scoring by human factor experts and such text descriptions are of limited value for this type of data collection, it still shows the scope of the problem—having also in mind that voluntarily reported incidents only represent the peak of an iceberg, with many incidents not reported at all.

Fletcher and colleagues published a review of studies describing the influence of nontechnical skills in anesthesia in 2002, summarizing that it is clear “ that nontechnical skills play a central role in good anesthesia practice and that a wide range of behaviors are important […] [including] monitoring, allocation of attention, planning and preparation, situation awareness, prioritization, applying predefined strategies/protocols, flexibility in decision-making, communication, and team-working” [p.426].

As increasing evidence suggested that human factors like communication, leadership, and team interaction influence the performance of cardiopulmonary resuscitation (CPR), Hunziker and colleagues presented a study in 2010 reviewing the impact of human factors during simulation-based resuscitation scenarios. Similar to studies in real patients, simulated cardiac arrest scenarios revealed many unnecessary interruptions of CPR as well as significant delays in defibrillation—two outcome-relevant parameters. The studies showed that human factors played a major role in these shortcomings and that medical performance, at least in non-routine situations, depends among others on the quality of leadership and team-structuring.

Jones and co-workers only recently systematically reviewed the literature on the impact of HFs in preventing complications in anesthesia due to poor airway management and highlighted recent national reports and guidelines, including the 4th National Audit Project (NAP4). NAP4 (2011) was the first prospective study of all major airway events occurring throughout the UK, reviewing any complications resulting from airway management that led to either death, brain damage, the need for an emergency surgical airway, unanticipated ICU admission, or prolongation of ICU stay. 184 reports were reviewed. Subsequent in-depth analysis identified HFs as having been a relevant influence in every case, with a median range of 4.5 contributing HFs per case. HFs in the report included for example : casual attitude toward risk/overconfidence, peer tolerance of poor standards, lack of clarity in team structures, poor or dysfunctional communication including incomplete or inadequate handovers, inadequate checking procedures, failure to formulate back-up plans and discuss them with team members, failure to use available equipment, attempts to use unknown equipment in an emergency situation, heavy personal workload, lack of time to undertake thorough assessment, equipment shortage, inexperienced personnel working unsupervised, organizational cultures which induce or tolerate unsafe practices, no formalized requirement to undertake checking procedures, incompatible goals, and reluctance to analyze adverse events and learn from errors.

The Sentinel Event Report of the Joint Commission analyzed the root causes of 764 sentinel events (patient’s death, loss in function, unexpected additional care and/or psychological impact) reported voluntarily in 2014. Human-factor-related root causes, including among others communication and leadership, were the leading root causes of sentinel events and made up 65% of root causes. Even though the data are not specifically linked to anesthesia practice, it is very likely that there exist strong parallels.

One of the latest simulation-based studies, performed by Weinger and colleagues in 2017 and explained in detail earlier (section on assessing performance, “Performance as a Function of Experience”), also shows a broad variety of human-factor-related hurdles for anesthesiologists when handling emergencies.

What are the implications of the Impact of Humand Factors and NonTechnical Skills on Human Performance?

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  Balancing the importance of technical and nontechnical skills during medical education and training. While technical skills and medical knowledge have always been at the core of medical education and training, the importance of NTS has—despite long growing evidence—only recently been recognized.

  
  
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  Acknowledgement of the importance of human factors as individual and team. One of the first steps for individuals and teams in minimizing and mitigating human frailties and strengthening human strengths—and in consequence reducing medical error and its consequences—is by acknowledging human factors as a part of human performance and thus acknowledging human limitation. The World Health Organization (WHO) states:

“A failure to apply human factors principles is a key aspect of most adverse events in health care. Therefore, all health-care workers need to have a basic understanding of human factors principles. Health-care workers who do not understand the basics of human factors are like infection control professionals not knowing about microbiology.” (p. 111)

Multitasking and Multiplexing

Sometimes multitasking—doing several things at a time—can be successful, depending on the situation and the tasks at hand. Yet professionals need to be aware that it can be unsuccessful when the situation or the tasks change. When task density becomes high, simple linear performance of tasks becomes impossible; instead more complicated processes of both multitasking and multiplexing are needed. Multitasking—trying to perform two (or more) tasks simultaneously—is frequent in hospital settings, but is virtually impossible to execute if the same cognitive resources are involved. Conducting two or more relatively simple tasks is often possible, such as observing the surgical field while asking the surgeon a straightforward question. Even then there is a risk that one task will be dropped or degraded. However, adjusting an infusion pump while calculating the upcoming dose of antibiotic for an infant would be difficult to do in parallel.

In common use, the term multitasking sometimes refers specifically to media multitasking—everyday attempts to simultaneously work, listen to music, check email and text messages, and search the web. Studies have shown that frequent media multitaskers perform worse on psychology laboratory probes of actual multitasking than those who are infrequent media multitaskers. Many suggest that true multitasking is impossible and that almost always there is a decrement of performance on some or all tasks when multitasking is attempted.

The degree to which media multitasking, or laboratory tests, relate to the kinds of multitasking performed by personnel in professional settings of many data streams and many tasks is as yet uncertain; it seems likely that in anesthesia care there are limits to what individuals can safely do on their own.

While simple multitasking in perioperative settings may work, when tasks are complex it may in fact be inefficient. Rather than conducting two (or more) activities in parallel, humans often do things sequentially but shift rapidly between items or back and forth across many simultaneous threads. If the tasks use different cognitive resources, this is referred to as multiplexing. Multiplexing brings the challenges that people (1) have to refocus their concentration each time they switch and (2) are more susceptible to distractions and errors. This is especially true if the tasks at hand involve intensive real-time control as opposed to being cognitively automatic. There is evidence that health care personnel are not aware of the risks of decreased performance when attempting to multitask.

Douglas and co-authors recently reviewed the current literature concerning multitasking in the health care setting. They suggest that multitasking typically results in increased time of task completion, increased stress, risk of memory lapses, and subsequent errors and accidents. Those performance limitations occur more often if one is forced to multitask by the environment and/or if the different tasks compete for the same local cognitive resource. Their review located only two studies on the association between multitasking and errors in the health care setting although nothing definitive was found. Executing two tasks at the same time was found to carry the risk of decreased accuracy and efficiency and to have an increased reaction time to environmental stimuli.

Multitasking During Handovers?

One study observed different modes of patient handover from the OR to the post-anesthesia recovery unit in six hospitals. The researchers compared handovers of (1) simultaneous transfer of equipment and information (i.e., a nurse connecting the monitor while at the same time receiving verbal information) to (2) sequential transfer (equipment is first connected and lines sorted, then verbal information follows). The findings from 101 observed handovers showed that 65% of them took place simultaneously. Interestingly, simultaneous handovers were not significantly faster than sequential ones (1.8 vs. 2.0 min). In review of postoperative handovers Segall and colleagues recommended: (1) standardize/structure processes (e.g., through the use of checklists and protocols); (2) complete urgent clinical tasks before the information transfer; (3) allow only patient-specific discussions during verbal handovers; (4) require that all relevant team members be present; and (5) provide training in team skills and communication. More information on handoffs is given in the later section on “Communication.”

Shared Situation Awareness

SA is a concept that can be applied to the individual (personal SA, see above), but also the team (shared SA). Team SA is defined as “the degree to which every team member possesses the SA required for his or her responsibilities” (p. 39). Within different professions and different physical positions in the room, the situational awareness and interpretation of the same case can differ substantially within a team, due to variation in experience, involvement, focus point, interest, knowledge, or information. Of course, not every bit of information can be shared with the whole team; doing so would overwhelm everyone. Yet, creating and maintaining an overall shared mental model of the situation across all team members is critical for determining the best plan of action for patient care. Some team communication in the operating room that seemingly does not serve an obvious purpose, might, in fact, be a gauging of shared mental models and therefore shared SA. Anesthesia professionals, for example, routinely assess the progress and possible complications of the operation by perceiving nuances in the conversation of the surgeons.

Shared mental models predict good team performance and were, for example, shown to be related to positive performance in trauma teams, with team leaders and followers actively working toward an information exchange. Adapted from psychology and management literature, Schmutz and Eppich introduced the conceptual framework of team reflexivity to health care. They propose that shared SA is fostered by components of team reflexivity, namely (1) pre-action briefing, (2) in-action deliberation, and (3) post-action debriefing. Fioratou and colleagues challenge the common model of individual and team SA and instead introduced the model of distributed situation awareness (DSA) to anesthesia, arguing that cognition actually involves elements of the (physical) environment, for example, the values on a monitor.

A multicenter study from Denmark explored shared mental models of surgical teams during 64 video-assisted thoracoscopic surgery lobectomies to explore familiarity of the people involved in the operation with each other; mutual assessment of technical and nontechnical skills in the other persons present during the operation; assessment of the perceived risk for the patient from the procedure and from the anesthetic; and noting of problems in the present co-works task management. There was poor agreement between team members’ risk ratings showing limitations in how much the members of the surgical team share a mental model about the patient and the related risks. A follow-up study demonstrated the connection between relevant clinical markers and shared mental models.

Other aspects of situation awareness have already been introduced within the “core cognitive process model” in an earlier section. Box 6.2 gives examples of reevaluation questions in order to maintain situation awareness.

Ambient Noise and Music

The workplace of anesthesia professionals—predominantly, but not exclusively, the operating room—is a very complex physical and cognitive setting. Unless there is an unusual effort to reduce sound levels the routine noises of the suction, surgical equipment (electrocautery, pneumatic or electric power tools), and monitoring equipment yield levels considerably higher than in most offices or control rooms. Other sound sources such as conversation and music are controllable. The potential interference of noise with communication and situation awareness among personnel in the OR is particularly worrisome to those concerned with optimizing teamwork in this complex work environment.

The use of music in the OR is now widespread. Many health care professionals believe that music enlivens the workday and can build team cohesiveness when all team members enjoy the music. Others note that in some cases the volume level of music makes it harder to hear the rhythm and tone of the pulse oximeter and alarms as well as work-related conversation between team members. A laboratory study by Stevenson and colleagues determined that visual attentional loads and auditory distractions additively reduced anesthesiology residents’ ability to detect changes in pulse oximeter tone.

A controversial study by two social psychologists, Allen and Blascovich, suggested that surgeon-selected music improved surgeons’ performance on a serial subtraction task and reduced their autonomic reactivity (i.e., “relaxed” them) when compared with control conditions consisting of experimenter-selected music or no music at all. The methodology of this study has been criticized. In response to Allen and Blascovich, several anesthesiologists challenged the notion that the surgeon’s preference for the type or volume of music can or should override the needs of other members of the team.

Murthy and colleagues studied the effect of OR noise (80 to 85 dB) and music on knot-tying ability in a laparoscopic skill simulator. They found no difference in time or knot quality in the conditions tested and concluded that surgeons can effectively block out noise and music. The invited commentary that accompanied the article brings up important issues: What impact does noise have on other members of the surgical team? How does noise affect communication between team members? Does noise affect judgment? The question of the proper role of music in the OR has no simple answer. Clearly, optimal patient care is the primary goal. Some surgical or anesthesia personnel explicitly forbid any type of music in the OR. A more common approach of many OR teams is to allow any team member to veto the choice or volume of music if they believe that it interferes with their work.

Reading and Use of Mobile Electronic Devices

The observation that some anesthesia professionals have been seen to read journals or books casually during patient care led to a vigorous debate of the appropriateness of such activity. Although it is indisputable that reading could distract attention from patient care, a study by Slagle and Weinger in 2009 suggested that when the practice of reading is confined to low-workload portions of a case, it has no effect on vigilance. Many comments about the issue were related not to the actual decrement in vigilance induced by reading but rather to the impact of the negative perception of the practice and of those who do it by surgeons and by patients, if they were aware of it.

This issue has been greatly magnified by now-ubiquitous smartphones and social media. Nearly all clinical personnel (other than those scrubbed into surgery) have a smartphone immediately at hand. These provide great temptation for both pull activities—reading email, websites, or social media sites—and push activities, notification of new text messages, mail, or social media posts. The wide variety of channels of information makes it far more likely for people to spend time interacting with their phones than with newspapers, journals, or books. The content available is never ending. In their survey, Soto and colleagues give a current update of the usage patterns, risks, and benefits of personal electronic device use in the operating room.

Distractions Caused by Work Itself

An important source of distraction is actually the work itself. That is, engaging in one task can distract attention from other important tasks. Repositioning the patient on the operating table (or rotating the table itself) can take a surprising amount of time and physical and mental effort. During these tasks it can be difficult, and in some cases impossible, to maintain all usual data streams, or to view, hear, or attend to them. Another highly distracting activity is the use of echocardiography, which requires focused attention on the image and manipulation of the probe and of the device’s interface. While it may generate crucial clinical information, it can also distract attention from other important monitors or the surgical field.

Interruptions

Beyond distracting attention from important data streams, various stimuli can also cause “interruptions” in the sequence of conducting a task. Campbell and associates found that slightly more than 20% of distractions—particularly interruptions—were associated with an observable negative impact. Such events are particularly problematic when they disrupt prospective memory which is one’s ability to remember in the future to perform an action or to resume interrupted tasks in the right spot. It is particularly prone to disruption by concurrent tasks or interruptions. In anesthesia, for example, if the anesthesia professional suspends ventilation temporarily (say to allow a radiograph to be taken), the intention to restart the ventilator depends on prospective memory and can be easily forgotten.

A variety of methods may preserve prospective memory of intentions. Visual or auditory reminders can be used (physiologic monitor alarms often serve this purpose whether intended or not), although the effectiveness of such methods is variable.

Resulting Implications

Clearly, for all these distractions and interruptions the pros and cons of policing them need to be balanced. In our opinion—similar to those of Slagle and Weinger —blanket policies against reading nonessential materials or interacting with mobile phones except for patient care needs are both doomed to failure and possibly detrimental. First, because they are hard to enforce and any intensive efforts to eradicate the use of such devices at work is likely to generate a tense work climate despite the best safety intentions of proponents. Second, because reading or phone use might actually counteract boredom in some situations and thus might increase performance. Third, these distractions are not necessarily any different from many other kinds of activities not related to patient care that are routinely accepted, such as social conversation among personnel. Of course, there are reasonable limits for such activities.

The bottom line is, to quote Slagle and Weinger: “(1) the patient must be the foremost priority and (2) being distracted or performing noncritical tasks during critical or unstable situations is inappropriate and dangerous ” (p. 282). In the end it is important for anesthesia professionals to keep in mind that there are potential pitfalls linked to distractions and that the anesthesia professional is responsible for modulating controllable distractions and for developing work processes that balance the cognitive load of tasks against their personal, clinical, or teambuilding utility. Allowing music during routine work (if all agree) and a modest amount of reading or smartphone use, but emphasizing the need to reduce or eliminate it when it is too distracting, the workload increases, or a situation becomes complex or urgent is one example. The threshold for abandoning any potential distraction to provide maximum attention to patient care should be rather low.

In response to the patient safety concerns related to distractions and interruptions in the OR and other patient care areas from the use of personal electronic devices for non-patient-related purposes, several professional societies and organizations have established position statements and guidelines to define appropriate use of those devices in the OR. Some health care settings have implemented a “no interruption zone” during critical phases of patient care activities, in the style of a “sterile cockpit” concept, derived from aviation regulations that prohibit crewmembers from engaging in any activity except those duties required for the safe operation of the aircraft during critical phases of flight.

Stress

Stress is a performance-shaping factor that influences human performance. To go into detail about stress is beyond the scope of this chapter. Therefore the reader is referred to other references for more details.

Sleep Debt

Sleep loss is cumulative and results in what is referred to as sleep debt. An individual who has obtained an optimal amount of sleep is better prepared to perform long periods of sustained work than one who is operating from a sleep debt. Because of the additive effects of chronic partial sleep loss, even minor sleep restriction on a nightly basis can insidiously accumulate into a substantial sleep debt. The only way to pay back a sleep debt is with sleep. Sleep debts are commonplace in our culture. The National Sleep Foundation’s annual survey continues to reveal that Americans chronically undersleep by 30 to 90 minutes each day. Shift work, long and irregular work hours, and the demands of family and recreation lead to irregular sleep patterns and prevent restful sleep. This is particularly true for health care workers, who often work in shifts, have long duty periods, and must frequently care for patients for long periods. To some degree it seems as if sleep deprivation might have led into a situation that is more dangerous than one thinks.

Circadian Rhythms

Our biological clock, responsible for the human circadian system, is synchronized to the 24-hour day by external stimuli referred to as “zeitgebers,” the most influential of which is the light-dark cycle of day and night. The circadian system is biphasic in that it produces a state of increased sleep tendency and decreased performance capacity during two periods throughout the 24-hour day—from 2 a.m. to 6 a.m. and from 2 p.m. to 6 p.m. These are periods when professionals are more vulnerable to incidents and accidents because the body clock is “turned off.” The circadian clock is very resistant to alterations, and it does not adjust rapidly to changes such as those produced by jet lag or shift work. Disruption of the normal circadian rhythm or incomplete circadian adaptation leads to acute and chronic sleep deprivation, decreased alertness, increased subjective fatigue, and decreased physical and mental performance.

Sleepiness and Alertness

Sleepiness and alertness are at opposite ends of a continuum. Daytime sleepiness is the most obvious effect of failing to obtain adequate sleep. Data from the U.S. Department of Transportation reveal that the greatest number of single-vehicle accidents takes place during the early morning hours when people are at a circadian lull of alertness. These accidents are thought to result from inadvertent lapses in driver attention brought about by extremes of sleepiness.

Both behavioral and subjective sleepiness can be masked by a stimulating environment. When environmental stimuli wane, physiologic sleepiness manifests itself as an overwhelming propensity to fall asleep. A person who is physiologically alert does not experience sleepiness as environmental stimuli decrease. For example, without physiologic sleepiness, an individual may become bored during a lecture but does not fall asleep.

Microsleep Events

The most extreme cause of impaired vigilance is the occurrence of actual sleep episodes (microsleeps) encroaching into periods of wakefulness. Microsleep events typically last a few seconds to a few minutes. They are intermittent in onset, and their impending occurrence is difficult for the individual to predict. Most individuals underestimate their level of sleepiness when they can be objectively shown to be extremely sleepy, thus making this problem even more insidious. This has significant meaning in the workplace and when driving home after long work periods.

Microsleeps are a sign of extreme sleepiness and are harbingers of the onset of longer sleep periods. Typically, they occur during periods of low workload or stimulation and when an individual is maximally sleepy. In addition, an individual’s performance between microsleep episodes is impaired. Frequent and longer microsleeps increase the number of errors of omission.

Evaluation of Physiologic Sleepiness in Anesthesia Residents

Using the Multiple Sleep Latency Test (MSLT), a sleep disorder diagnostic tool, Howard and colleagues evaluated the physiologic (objective) daytime sleepiness of anesthesia residents under three different conditions: (1) baseline (daytime shift, no on-call duty period in the previous 48 hours), (2) post-call (immediately after a 24-hour work and in-house on-call period), and (3) sleep extended. In the sleep-extended condition, residents were told to maximize sleep and were allowed to arrive for work at 10 am (3 to 4 hours later than normal) for 4 consecutive days before testing. They were not on call during this time. The sleep-extended condition was included to provide a true control state of maximal rest and optimum alertness. In this study, for anesthesia residents the MSLT scores for baseline as well as for post-call condition revealed the nearly pathologic levels of daytime sleepiness seen in patients with narcolepsy or sleep apnea. The baseline group slept an average of 7.1 ± 1.5 hours per night, whereas the post-call group reported an average of 6.3 ± 1.9 hours of sleep during their night on call. Ironically, although the on-call periods occurred during rotations that often have very busy call nights, only a few subjects were, in fact, awake most of the night. In the sleep-extended condition, the subjects extended their sleep to an average of more than 9 hours per night, and MSLT scores were in the normal range. These results clearly demonstrate that medical personnel who have not been on call cannot be assumed to be rested when compared with fatigued post-call residents. These data also indicate that under normal working conditions, the resident physicians studied were physiologically sleepy to nearly pathologic levels. Notably, these data cast substantial doubt on previous studies of the performance of medical personnel that have relied on the assumption that individuals working under normal conditions are truly rested.

Evaluation of Subjective Sleepiness in Anesthesia Residents

The previously mentioned study also investigated the connection between subjective and physiologic sleepiness. In the previously discussed study, Howard and colleagues also investigated the degree of discrepancy between the residents’ subjective sleepiness (how sleepy they felt) and their physiologic sleepiness (how easily they fell asleep). Subjects’ self-reported sleepiness immediately before each sleep opportunity did not, in general, correlate with their measured sleepiness. The authors also found that subjects demonstrated little ability to determine whether they had actually fallen asleep. For example, in 51% of trials in which the electroencephalographic and electro-oculographic measurements showed that the subject had fallen asleep, the subjects thought they had remained awake throughout the test. These results support the contention that medical personnel are physiologically vulnerable to degraded alertness yet are unable to perceive this decrement. Thus, an anesthesia professional could, in fact, fall asleep during a case, awaken, and be totally unaware of the lapse in vigilance.

Mood

Long work hours, fatigue, and sleep deprivation have been shown to bring about consistent and dramatic changes in mood and emotions. Depression, anxiety, irritability, anger, and depersonalization have all been shown to increase during testing of chronically fatigued house staff. These emotions are an obvious source of stress between anesthesia professionals and their co-workers, patients, and families. The relationship of mood, performance, and patient safety has yet to be determined.

Sleep Inertia

Sleep inertia corresponds to the period of reduced ability to function optimally immediately on awakening. This phenomenon usually occurs when individuals are awakened out of slow-wave sleep and is manifested as grogginess and impaired performance lasting as long as 15 to 30 minutes after awakening. Sleep inertia can also occur after being awakened from normal sleep and is most common during the early morning circadian trough (2 to 6 am). Depending on the preexisting level of sleepiness, individuals who take naps longer than 40 minutes are at greater risk for sleep inertia on awakening.

Effects of Fatigue on Anesthesiologists’ Performance and Patient Outcome

It is highly uncertain as to whether, how, or in what circumstances these established psychophysical changes might interact with clinical work processes to affect patient safety in anesthesiology. Various methods are used for assessing an individual’s level of sleepiness, including behavioral indicators, subjective measures, and physiologic (objective) measures.

The survey by Gaba and associates revealed that more than 50% of respondents believed that they had made an error in clinical management that they thought was related to fatigue. In another survey of anesthesiologists and CRNAs, 61% of respondents recalled having made an error in the administration of anesthesia that they attributed to fatigue. In a study in 2011, a large, national, random sample of CRNAs in the United States was asked to complete an anonymous survey to quantify sleep activity. Findings of the almost 1300 respondents revealed that nearly 16% have experienced sleep-related behavior during a surgical case, and close to 50% have witnessed a colleague asleep during a case. A similar survey of CRNAs was conducted in 2015, where nearly 30% of the 325 respondents reported they had committed a patient care error because of fatigue.

The challenge of sleep deprivation and fatigue in medical personnel was addressed by the Joint Commission on Accreditation of Healthcare Organizations in 2011 in a Sentinel Event Alert on “Health Care Worker Fatigue and Patient Safety.” The Sentinel Event Alert is public and can be retrieved from the homepage of the Joint Commission. Sinha and co-workers ask: “The fatigued anesthesiologist: A threat to patient safety?” and Gregory and Edsell picked up the topic in their educational publication in 2014.

Considerable research on fatigue effects has targeted the transportation industries, especially driving which needs both continuous vigilance and psychomotor skill. If a driver has microsleeps lasting many seconds a problem is likely, unless the road is quite straight or there is an autosteering/autospeed autonomy. Even in health care, studies have largely been carried out in hospital ward settings where, during night on-call shifts, they may have responsibility for many patients. The anesthesiology environment is different. Each patient having anesthesia will have at least one anesthesia professional in constant attendance and that individual is not directly responsible for other patients at the same time. Moreover, although vigilance is indeed the slogan of the ASA, there are few situations that require sustained second-by-second attention. The demand for high vigilance and effort does not usually occur at random; such situations are usually present at induction, emergence, and a few key milestones during the surgical procedure. Critical events are uncommon, and even when the chain of accident evolution has begun, the clinical team will likely have multiple opportunities to detect and correct it before any substantive negative impact has occurred. Thus, while anesthesia personnel may be prone to fatigue, and complaints about sleepiness and fatigue are common, the probability of a negative patient outcome during anesthesia directly attributable to sleepiness alone is very small. In health care, there is no formal mechanism for evaluating causation in adverse events, let alone for evaluating sleep-wake issues and fatigue, so one does not know the full contribution of this factor to negative outcomes. As for many aspects of human performance, variables that can be reliably and precisely measured do not capture the complexity or the typical resilience of clinical work. Conversely, measures and techniques that do address such factors are by nature non-quantitative and invasive.

Howard and colleagues conducted a study of rested versus sleep-deprived (awake for 25 hours on a pseudo-on-call period) anesthesiology residents by collecting multiple measures of performance during a 4-hour high-fidelity simulation scenario: Mood questionnaire, PVT psychomotor reaction time, response time to secondary task probes, and response to changing clinical events. Psychomotor tests revealed progressive impairment of alertness, mood, and performance over the course of the pseudo–on-call period, as well as on the experimental day, when compared with the well-rested condition. Secondary task probe response times were slower after sleep deprivation, although this reached statistical significance for just one of three probe types. No statistical difference in case management between conditions was reported—in fact, subjects in both conditions made significant errors. Sleep-deprived subjects cycled (often rapidly) in and out of sleepy behavior, and the most impaired individuals showed such behavior for more than 25% of the experiment (60 minutes).

A key thing learned about fatigue during this study was that highly fatigued anesthesia personnel in simulations are not either awake all the time or asleep all the time. Rather they usually cycled frequently in and out of states of apparent wakefulness, drowsiness, and microsleeps throughout the simulated case. Typically, when awake their performance was at most mildly degraded but when they showed extreme drowsiness or were actually asleep their performance was essentially zero. Participants were observed being totally asleep at one moment but awakening just in time to happen to catch a probe stimulus or clinical event, and respond to it satisfactorily. For most subjects the fraction of time spent in highly impaired states was low as their microsleeps were brief, in part because even a quiet routine clinical setting has a variety of stimuli, including other personnel and their tasks. The intrinsic redundancies in the OR team, the potential benefits of monitor alarms, and the resilience of clinical systems and patients may explain why catastrophes during anesthesia are very rare even though many operations are conducted with personnel suffering from substantial chronic and acute fatigue.

Fatigue Countermeasures

Anesthesia professionals cannot prevent sleepiness by willpower alone because it is a fundamental physiologic drive. Strategies that institutions or practitioners can use to minimize the negative effects of sleepiness and fatigue on performance include: education and promotion of safety culture, improved sleep habits, rest breaks at work, strategic napping, medications and social drugs, and light therapy. Strategies that national bodies and professional societies and organizations can call for are reasonable duty hour requirements.

Duty Hour Requirements

One direct regulatory strategy to minimize sleep deprivation has been to limit the work hours of clinicians. For the most part this has been attempted only for those in training (who traditionally have worked very long hours both during the day and in nighttime on-call). Results of process and outcome studies have varied but there has been no proof that such regulations, by themselves, improve patient safety. Changing work schedules will not eliminate chronic fatigue, and in settings where clinicians at night may cover large numbers of unfamiliar patients the probability of information loss and confusion across the handoffs may outweigh any benefits of greater alertness. Yet, these findings may not apply to the anesthesiologists’ operating room environment in the same way. The previous studies provided addressed the effects of sleep deprivation and fatigue on physician performance and well-being.

Back in 2003 the Accreditation Council for Graduate Medical Education (ACGME) instituted the first set of common duty hour requirements for all accredited residency training programs in the United States. Those requirements were revised in 2011 in response to the 2009 Institute of Medicine (IOM) report entitled Resident Duty Hours: Enhancing Sleep, Supervision, and Safety. A white paper published by Blum and colleagues debates the latest information and innovative practices on the topic and discusses how to best implement the 2009 IOM recommendations. Work hour regulations in the European Union and in Australia or New Zealand are much more stringent than they are for trainees in the United States. For more details on work hour regulations see also further literature.

Education and Safety Culture

A first and relatively simple and inexpensive step in addressing sleepiness and fatigue of medical personnel is to educate practitioners and the administrators of health care institutions about the impact of sleep issues on work performance, mood, job satisfaction, and health. Educational programs covering sleep deprivation, circadian disruption and fatigue, and countermeasures have been enthusiastically adopted by an increasing fraction of the aviation community. Similar programs should be developed for the health care community. However, it is clear at both the individual and organizational level that education will not be sufficient to address this issue fully. Other competing forces, for example measures of production versus safety, are very powerful and difficult for practitioners to manage.

The organizational framework plays a major role. Only if fatigue is seen as an organizational issue affecting safety negatively and safety is made a high organizational priority with all the resulting consequences, will fatigue-related safety issues be minimized. For an organization that implies, for example, that (a) tired staff are not always implicitly expected to work under all circumstances, (b) opportunities are created for tired staff to rest and to recover (i.e., regular rest breaks, strategic napping, etc.), and (c) an organizational safety culture is fostered that allows anesthesiologists to call for the assistance of a colleague (teamwork, speak up, see next section) when they know that they are impaired (from fatigue or for any other reason), without any negative consequences (cowardice, etc.). For additional countermeasures also see the Sentinel Event Alert of the Joint Commission introduced earlier.

Closed Loop Communication

For example, addressing team members by name and engaging in closed loop communication ( Fig. 6.6 ) can help avoid misunderstandings. Closed loop communication includes (a) when the sender initiates communication, the receiver confirms that the communication has been heard by repeating the content of the communication and (b) when a delegated task is finished, the receiver gets back to the sender and the sender confirms the feedback. For instance, instead of saying “Can someone call for help, please?” closed loop communication presents as follows : “Jeff, can you call for help, please.”—“Yes, Megan, I will call for help immediately.”—“Megan, I have called for help and they are on their way.” —“ Ok Jeff, thank you. ” El-Shafy and colleagues evaluated the effectiveness of closed loop communication in trauma settings of a level I trauma center in the United States, analyzing all verbal orders issued by the trauma team leader for order audibility, directed responsibility, check-back, and time-to-task-completion. In total, 89 trauma videos were reviewed, with 387 verbal orders identified. Of those, 126 (32.6%) were directed, 372 (96.1%) audible, and 101 (26.1%) closed loop. On average each order required 3.85 minutes to be completed. There was a significant reduction in time-to-task-completion when closed loop communication was utilized. Orders with closed loop communication were completed 3.6 times sooner compared to orders with an open loop. The authors highlighted that closed loop communication not only prevents errors, but has the potential to increase the speed and efficiency with which tasks are completed in the setting of trauma.

Stairway of Communication and Closed Loop Communication: The importance of proper communication.

(1) Especially when dealing with complex situations under time pressure, but also during routine work, people tend to “mean” or “think” a lot, but “say” little. It is important to let other team members know what one thinks in order to create shared mental models of a situation. (2) For several reasons, not everything that is said is necessarily heard by those who should hear it. The sender needs to ensure that the message was heard by the receiver and the receiver needs to confirm the message (= closed loop communication). (3) Acoustic hearing and mental understanding are not the same. “Closely monitor this patient” might be clearly heard, but what is meant is open for interpretation on a large spectrum. Misunderstanding can result, but can be smoothed out. (4) Some tasks may be forgotten, making double checking necessary. Some tasks need time to be completed, some tasks may fail. No matter what, the team needs to know (= closed loop communication).

ISBAR Tool

Another effective communication tool especially useful for sharing information is the ISBAR concept ( Fig. 6.7 ), often abridged to just SBAR. The acronym stands for I ntroduction, S ituation, B ackground, A ssessment, and R ecommendation. It originated in U.S. nuclear submarines and has also been used in the airline industry. ISBAR may be used variably by different members of the OR team. Its use is associated with increased accuracy in communication and safety climate and a decrease in communication errors as well as in unexpected death.

Example of the use of the communication tool ISBAR.

In the medical setting, ISBAR is a universally applicable communication tool that is usable in several settings, including for example face-to-face as well as telephone handovers in the OR or in the anesthesia post-anesthesia care unit. It also can be used for the briefing of new team members during emergencies and for briefing senior staff who has been asked for help. In the literature the slogan “Think—Talk—Write—ISBAR” can be found and characterizes the broad field of application of the idea. Shahid and Thomas give an up-to-date narrative review of the current literature on (I)SBAR, the challenges of communication among health care providers, and the proper use of the tool, and compares it to other communication tools that exist in order to assess their strengths and weaknesses. For -detailed information the reader is referred to this review.

Because it assists the transfer of important information in limited time, ISBAR has been adopted by many health care organizations across the world. Medical associations and leading health care organizations, like the German Association of Anesthesiology and Intensive Care Medicine—Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin (DGAI), the Australian Commission for Safety and Quality in Health Care (ACSQHC), the Institute of Healthcare Improvement (IHI), and the WHO have endorsed the (I)SBAR method as a standard communication tool, when appropriate, for health care providers. The experience in the United States is that SBAR has been adopted (in principle if not always in widespread practice) for nurses but is not frequently used by physicians.

Handoff Protocols ^∗

∗ Acknowledgment: This section on handoffs was contributed by Lisa Sinz, MD (Penn State University School of Medicine).

Another aspect of safe and effective communication concerns post-intervention handoffs and intraoperative transitions of care responsibility, which are known settings of risk for critical information to be lost. Intraoperative anesthesia care transitions are known to be associated with adverse postoperative outcomes, with a similar effect size for attendings, residents, and nurse anesthetists. Sometimes though the new person may be able to take a fresh look at the situation, catch errors, or find opportunities to improve care.

Handoff protocols are intended to minimize patient risk by creating a designated time and framework to ensure that crucial information is not missed during care transitions. There is an increased focus on formal protocols because the number of patient care handoffs has markedly increased in some settings due to work hours limits. Protocols can be divided into conceptual models (e.g., IQ—a reminder that the caregiver should inform the receiving provider about the details of the patient and case and then allow them to ask questions before leaving) or scripted models (e.g., I-PASS which stands for I llness severity, P atient summary, A ction list, S ituation awareness and contingency plans, and S ynthesis by receiver, or I PASS the BATON which stands for Introduction, Patient, Assessment, Situation, Safety Concerns [the] Background, Actions, Timing, Ownership, Next).

Another comparison can be made between verbal and written handoffs and also supplementing a primarily verbal handoff with written information. When a patient’s care is being transferred to a different care team, such as when a patient moves between the intensive care unit and the operating room, a team-to-team handoff is beneficial because the report and questions about the patient are consolidated for both teams (e.g., time out for sign out). A good handoff process should be used for every transition, including intraoperative transfers for breaks, dropping off the patient in the PACU, or changes from one anesthesiologist to another during a case. Using a checklist or structure can help prevent lapses, but regardless of the tool used, the goal is to provide clear and complete communication to protect the patient from medical errors.

Effective Delegation of Tasks

Delegation of tasks is sometimes ineffective leading to frustration on both sides: the person delegating and the person meant to perform the tasks. A common failing is when the delegation is incomplete and subject to assumptions, leaving too much room for interpretations.

The granularity of delegation instructions may depend on the personnel involved. For peer anesthesia professionals it may work to delegate a whole area of responsibility, such as “Sara, can you handle airway management please?,” trusting that person to make the necessary decisions on their own. In other cases, especially with less experienced personnel, simply saying “Michael, take care of the blood pressure” may be insufficient because both the leader and the follower may have different assumptions of what that means in practical terms. With such a mismatch both parties may be unhappy. In such settings a more detailed delegation instruction may be needed, such as

“Michael, because our patient has a known hypertension and a risk for stroke, try to keep the diastolic blood pressure at or above 80 mm Hg. If necessary, give up to 500 ml crystalloid and, if necessary, small doses of ephedrine. If that doesn’t handle it let me know. Any questions?”

Asking Open-Ended Questions

A useful and simple means of communication, particularly in interprofessional and interdisciplinary settings, is to ask about other team members’ points of view and plans using open-ended questions.

Know the Environment (CRM Key Point 1)

Knowing fully the environment of work is critical. Environment refers to equipment, supplies, processes, and people, as well as how they vary from case to case, or from location to location, time of day or day of the week. This knowledge reduces stress in the case of an emergency and provides more available mental capacity and prudence to deal with the case. It is important to know who can be asked for help, how to mobilize help quickly, and how long it will take help to arrive. Like pilots, anesthesia personnel can be expected to know in detail how to use all equipment and supplies, which in anesthesiology includes anesthesia machine, defibrillator, infusion and blood administration system as well as how to troubleshoot them or switch to backup devices. The experience of the authors as clinicians and teachers in real and simulated anesthetic cases suggests that many anesthesia professionals lack sufficient depth of knowledge or skill in the operation of their equipment. That these systems are not always designed optimally from a human factors standpoint only increases the need for the individual clinician to thoroughly learn about and practice with all their features and pitfalls.

Anticipate and Plan (CRM Key Point 2)

Anticipation is key for goal-oriented behavior and it also helps avoid unpleasant surprises. Anesthesia professionals routinely consider in advance the requirements of a case and plan for its key milestones. In addition, they must imagine what could go wrong and plan ahead for possible difficulties. Savvy anesthesia professionals expect and are prepared for the unexpected. And when it does strike, they then anticipate what could happen next and prepare for the worst. In this context people often talk about “staying ahead of the game” or “not falling behind.” Resources can be mobilized and used on the fly, but it is better if their possible need is anticipated and planned for.

For any case, a sound plan matches the anesthetic technique to the patient’s disease state, the technical requirements of surgery (e.g., position of the patient), the anesthesia equipment available, and the skills of the anesthesia professional. It also includes specific backup procedures and contingency plans to be used if the original plan fails or needs to be changed. Often, faulty plans can result when underlying disease states are missed or ignored because of inadequate data gathering during preoperative evaluation. Poor planning may also result from the hazardous attitude of invulnerability. Note that a faulty anesthetic plan will expose the patient to risk even if it is carried out perfectly.

For anticipating and planning to be most effective, it should ensure the coordination of all members of the patient care team. One way to do so during routine cases is the use of briefings. Over the last 10 years there has been a major movement to formalize such briefings (e.g., mandatory preoperative briefing of the WHO Surgical Safety Checklist, Patient Safety Huddles).

Call for Help Early Early Enough to Make a Difference (CRM Key Point 3)

Calling for help is associated with better individual and team performance. Knowing one’s own limitations and calling for help early are signs of rationality, strength, and patient-centeredness. Trying to handle everything alone or toughing out a critical situation is dangerous and unfair for everyone. The decision of when to call for help is complicated, but the key point is to do so early enough that the assistance can make a difference. A call so late that the patient is beyond rescue is futile. Knowing in advance who might be available and planning how you would use them will facilitate their utility.

Some typical triggers for calling for help that apply to any anesthesia professional at any level are (1) when there are too many tasks to do, (2) when the situation is already catastrophic (e.g., cardiac arrest, difficulty securing the airway), (3) when serious problems are becoming worse or are not responding to the usual maneuvers (or both), and (4) when you do not know what is going on.

For novice anesthesia professionals, calling for help very early is frequent as they are not expected to handle any critical aspect of a case (e.g., induction of anesthesia) without supervision or assistance. For experienced personnel it will be less frequent, as they are fully able to handle more things alone, but mobilizing help is still critically important. Many situations that would spin out of control can be readily resolved with appropriate and timely assistance.

Whereas prior research on these kinds of backing-up behavior has indicated that it is beneficial to teams, nothing is perfect. Barnes and colleagues published a critique of aspects of backing-up behavior in their article “Harmful help,” citing for example decreased work on subsequent tasks after receiving high amounts of backup. A related concept is that of social shirking in which a task that is typically done separately by two people, to gain redundancy, instead is shirked (dropped) by one or both of them assuming that the other is taking care of it.

Establish Leadership and Followership With Appropriate Assertiveness (CRM Key Point 4)

Leadership involves structuring the team, planning, deciding, and distributing tasks. Leadership does not imply knowing more than everyone else, doing everything alone, or putting other people down. Followership is as important as leadership. Team leaders and team followers are jointly responsible for the well-being of the patient (see earlier section on “speaking up”). Since speaking up requires the crossing of many personal and interpersonal hurdles (e.g., fear of repercussions or arising disadvantages), team members may need explicit invitations to contribute and shows of appreciation by the team leader, sometimes referred to as leader inclusiveness.

Wacker and Kolbe wrote about leadership, followership, and teamwork in anesthesia:

“Intuitively and empirically, leadership and teamwork are essential for team performance, patient safety, and patient outcomes in anesthesia and perioperative care. […] Current research supports the concept that little explicit leadership is usually required during standardized routine work, but active and even directive leadership is important in unexpected, novel, or stressful situations.” (p. 200)

In their work they give an overview of how leadership practices in anesthesiology optimally change (implicit vs. explicit team coordination) according to clinical work phases and special situations (routine situations with low or high task load; unexpected minor or major events; initiation and maintenance phase). Rosenman and colleagues give a systematic review of leadership and leadership training for health care action teams.

Distribute the Workload. Use the 10-Seconds-for-10-Minutes Principle (CRM Key Point 5)

One major aspect of strategic control of attention is the active management of workload. Rather than passively dealing with rising or falling workload, the anesthesia professional actively manages it. Among others, Schneider and Detweiler and Stone et al. described the theoretical basis for a variety of strategies of workload management. These strategies were addressed specifically for anesthesiology by several investigators. The anesthesia professional actively manages workload by the following five techniques:

• 1.
  

  Avoiding excessive workload situations (i.e., by anticipating and planning, CRM key point 2; calling for help early, CRM key point 3). Experts may choose techniques and plans that reduce the workload (especially when their individual and team resources are limited), even when those plans are otherwise slightly less desirable from a technical standpoint. For example, a single anesthesia professional working alone may opt not to use a high-tech, high-workload monitor (e.g., TEE) for a given case because the effort to use it might outweigh the likely information gained.

  
  
• 2.
  

  Distributing workload over time (i.e., by setting priorities dynamically, CRM key point 15). The anesthesia professional can prepare for future tasks when the current load is low (preloading) and can delay or shed low-priority tasks when the workload is high (offloading). Resources that require a significant amount of workload to prepare, such as vasopressor infusions, are often made ready before the case starts. Many tasks are made up of several subtasks, each of which has a finite duration. Because close attention may not be required during each of these subtasks, they can sometimes be interleaved with a fixed amount of attention (multitasking/multiplexing, see earlier section).

  
  
• 3.
  

  Distributing workload over personnel (i.e., by applying the actual CRM key point 5; by coordinating the team, CRM key point 13). When workload cannot be distributed over time and when additional people are available, tasks can be distributed to them with certain considerations: (a) Some resources can be handled by the individual anesthesia professional, whereas others require additional personnel; (b) Some tasks are completely incompatible, for example any activity that requires being gowned and gloved will preclude that individual from performing nearly all other tasks; (c) In very time-sensitive situations distribution over personnel may be needed whereas for more routine situations a single individual may be sufficient for the same set of tasks.

  
  
• 4.
  

  Changing the nature of the task. The nature of a task is often not fixed. They can be executed to different standards of performance; as standards are loosened, the workload required to perform them is reduced. For example, during periods of massive blood loss, the anesthesia professional focuses primarily on administering blood and fluids and on monitoring blood pressure. The acceptable limits of blood pressure may be widened to reduce the need for more frequent interventions.

  
  
• 5.
  

  Modifying distractions and offloading routine activities. In addition to the attentional demands of the anesthesia professional’s core tasks, any clinical environment may be full of distractions. Expert anesthesia professionals modulate the distractions by eliminating them when the workload is high and allowing them to occur when the workload is low (to improve morale and team building). Similarly certain routine tasks (e.g., entering non-critical information into the anesthesia record) or courtesy activities (e.g., tying the gown of a surgeon or nurse) may be performed by the anesthesia professional only when workload is low, but not when it rises.

Appropriate assertiveness is important. A frequent observation in simulations and real cases is that anesthesia professionals may be too quiet or too casual, even for situations that demand urgency and assertiveness. But choosing the appropriate level and style of assertiveness is also important because being excessively assertive, especially for non-critical situations, will anger or annoy co-workers and lead to suboptimal results.

Exercising effective followership (see CRM key point 4, exercise leadership and followership with appropriate assertiveness), team members should also look actively for work that needs to be done. The team leader should not have to think of and order every single task or activity. Proper communication will be needed to coordinate the work (see CRM key principle 7, Communicate effectively).

We always have 10 seconds! Patient care is very rarely a high-speed discipline where seconds matter—initiating CPR is one example. Usually patients deteriorate in minutes to hours. Despite the stress and intrinsic pressure to perform immediate actions (“do something, do something now!”) there is often some time to think of a plan. Trying to be too fast may lead to avoidable errors.

To address this Rall and colleagues developed the 10-seconds-for-10-minutes principle, meaning, metaphorically, spending 10 seconds in order to achieve a better coordinated team for the next 10 minutes. Stopping for symbolically 10 seconds in an emergency feels counterintuitive, but once used to it, it is a very effective way to improve performance and patient safety. The 10-for-10 principle has spread to many health care settings (anesthesia, ICU, prehospital, etc.).

The concept can be extended to mean that sometimes an investment of time in an activity—even many minutes—can yield big dividends in various ways (including time saved) in the future. The benefit of strategic investment of time appears to be greatest in key situations, such as (a) the making of a provisional diagnosis and the beginning of treatment, (b) planning for complex interventions, or (c) when the team feels stuck because the initial diagnosis seems incorrect, or when the usual treatment of a known problem is not working ( Fig. 6.8 ).

The “10-seconds-for-10-minutes-principle”—“10-for-10.”

When making a diagnosis or feeling stuck, perform the 10-seconds-for-10-minutes team timeout and check to see “what the biggest problem is right now” (Problem) . Clarify this with all available team members (Opinions) . Gather the information available (Facts) . Plan the treatment, including the desired sequence of actions. Distribute the workload by assigning tasks and responsibilities. Check actively with all team members about any further concerns of suggestions. Then act as an organized team.

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