In this exploratory study, CTA tools were applied to identify cognitive aspects of critical care practice in two academic ICUs. CTA is a tool within the theoretical perspective of NDM. Several cognitive activities that members of the critical care team engage in, as part of their decision-making process, were identified including pattern recognition, uncertainty management, strategic vs. tactical thinking, team coordination, creation and transfer of meaning through stories, and maintenance of common ground.
Researchers using the NDM framework have examined expert performance with a wide variety of professionals such as firefighters [12], weapons directors [13], anti-air warfare command and control officers [14], pilots [15], electronic warfare officers [16] and critical care nurses [17]. By studying the cognitive aspects of expert performance in these domains, NDM researchers have been able to make recommendations on how to improve training and system support to facilitate performance of both experts and non-experts.
CTA comprises a series of techniques for knowledge elicitation and knowledge representation ranging from the CDM [7, 8, 17, 18] to the Knowledge Audit [19] to a variety of team CTA techniques [20]. The tools allow an understanding of the cognitive aspects of the expert's behaviour; in particular the judgment, decision-making and problem-solving skills that are so critical in the time-pressured, uncertain and ever-changing environment of the ICU.
These data are neither the first use of cognitive psychology techniques nor cognitive task analysis in particular, within the domain of critical care. Cohen and colleagues used the theoretical framework of distributed cognition (also used extensively in aviation and the military) to examine cognitive errors in a busy psychiatric emergency department [21]. They discovered a number of worrisome system problems associated with cognitive tasks distributed across people, time, space and technologies. One clear similarity between their findings and our own is the concept of fragmentary (or 'mini') teams as sources of cognitive dissidence and potential errors [21]. Others have used observations and interviews to model emergency room hand-over [22] and critical care workflow [23]. All three studies focused on creating systems and technologies to support current workflows. Again, working to support existing workflow, Ho and colleagues observed communication and sense-making during critical care rounds [24]. Closest to the intent of our work is a study by Renard and colleagues where the tasks associated with medication prescribing were analysed, simulated and postulated amenable to redesign [25].
There are several key cognitive areas where this exploratory work suggests deeper analysis will be fruitful and necessary.
Assistance with mental model creation
Pattern recognition is challenging because of the massive quantities of data with which critical care practitioners are faced. Within a sea of data, it can be extremely challenging to pick up a 'signature' or a pattern. For pattern recognition to be enhanced, better delineation of templates within critical care need to be identified with their essential data elements, and these templates must be explicitly taught to trainees. Rather counterintuitively, the actual number of data elements may be rather small [26, 27]. Only after consistent patterns are discovered can their use by the physicians and nurses be studied.
A robust notion of mental models, that takes into consideration causal connections and the meaning of those connections in a given context, is a concept called fragmentary mental models [28]. Fragmentary mental models are packets of local cause/effect connections that permit people to connect smaller pieces into a bigger picture. Fragmentary mental models are put together as the situation warrants to construct a comprehensive just-in-time mental model of the situation – one that is flexible, dynamic (changing over time) and context-specific [28, 29]. Experts have a richer and broader repertoire of fragmentary mental models than novices, helping them to draw inferences and to make sense of situations.
Supporting shifts between, or separation of, strategic and tactical thinking
Both tactical and strategic thinking are central to critical care medicine. Strategic thinking enables the practitioner to consider the big picture (single patient, multi-patient and/or multi-unit), recognise patterns and trends, set priorities and consider alternatives. In a traditional academic setting strategic thinking is generally the responsibility of the attending position and tactical thinking (e.g. running the tests, assessing laboratory values and coordinating with other members of the team) is the responsibility of the housestaff. Being able to transition between tactical and strategic thinking is central to effective critical care medicine as it is currently practiced; yet this is no simple task. Most of the training of residents is focused on tactical thinking. As a result of not operating at the strategic level, it can be difficult for housestaff to effectively prioritise tasks.
Supporting uncertainty management
It is often assumed that uncertainty stems from a lack of information. If that were the case, the problem of uncertainty could be solved by technological advancements that provide practitioners with access to all possible data. Yet, uncertainty is, in fact, a lot more complex than just missing information [30]. It is often the complexity of the data and the difficulty in integrating the data that leads to uncertainty.
Although physicians may feel more confident in their decision-making when they have more information available, evidence suggests that decision-making performance actually declines with too much data [26, 30, 31]. More data can simply confuse the issues, making it difficult for physicians to integrate and/or interpret it [26, 31]. In addition, the overwhelming majority of information is typically irrelevant to the immediate problem and can get in the way of effective decision-making.
There are practical ramifications of uncertainty in the context of the discussion of templates, patterns and mental models. Appreciating uncertainty is crucial to avoid being locked into an incomplete and, possibly, incorrect, mental model (a cognitive error sometimes called 'premature closure').
Support creation and transfer of meaning through stories
Related to common ground is the use of stories in the ICU. In many circumstances, important information is being lost in the transition of care from shift to shift. Recent data suggests that because housestaff work restricted work hours, shift hand-over errors exceed the number of errors due to fatigue [32]. This finding suggests critical elements of the patient's story are not being communicated. A broader understanding of stories in the ICU – including the function they serve, how they are created and shared within the team, and how technology can support those processes – may offer significant leverage toward ameliorating this problem.
Assisting team coordination and common ground
Over the past 10 years, the health care domain has adopted lessons that were learned from the aviation industry, incorporating crew resource management principles to address the challenges of teamwork. A different way to think about the cognitive challenges of teamwork is through the concept of common ground [33]. In this exploratory study, some of the barriers to common ground were identified that ICU teams face such as role ambiguity, the shifting nature of the teams and a higher number of shift hand-overs due to hour restrictions.
Redesigning shift hand-overs or rounds procedures may be a way for ICU teams to enhance common ground [34–36]. A central key to sustaining common ground in teams is to catch discrepancies or possible erosions in common ground, and to take preemptive action to avert a potentially disastrous breakdown [37, 38]. Modified shift hand-over or rounding procedures should elicit potential discrepancies before they become entrenched. The procedures and technological support systems will most effectively support common ground if they involve the following activities: first, including various clarifications and reminders that can be used as a means of simply validating an assumption or giving team members a chance to challenge assumptions; second, updating others about changes that occurred outside their view or when they were otherwise engaged; third, monitoring the other team members to gauge whether common ground is being seriously compromised and is breaking down, along with actively encouraging all clinical team members to contribute their knowledge; fourth, detecting anomalies that signal a potential loss of common ground; and fifth, repairing the loss of common ground.
The study has several limitations. The study was, by design, exploratory; more questions were raised than answers delivered. Caregiver sample sizes are small and represent only one model of critical care delivery (i.e. the academic medical centre); the findings are not likely to be directly extensible to other practice models. Few units operate with more providers on rounds. Further, there was no systematic effort in this study to ensure a full cross-section of rounding participants. In units run without housestaff the division of strategic and tactical think is not relevant for separation of the cognitive planes, and rather the focus will need to be more effective transitions between them.
This exploratory work indicates that there is much work to be conducted. One pressing issue is to ensure that the primary cognitive issues are identified so that these cognitive tasks are appropriated distributed and then adequately supported (but not only technological support [39]). Another critical concern is with technologies that hinder, rather than help practitioners, due to their complexity and/or poor design. Unfortunately, human error is all too often simply transformed, or even amplified, by technological change, and new demands are levied which afford new ways to make mistakes. Thoughtful, well-tested systems that effectively support clinical teamwork, based on an understanding of the cognitive and environmental demands of clinical teams in the ICU, is the crucial first step toward future technology acceptance.