Management and Coordination of the Core Process

Empirical studies have clearly demonstrated that attention-sharing is needed among cognitive levels, among tasks, and often among problems. The intensive demands on the anesthetist's attention could easily swamp the available mental resources. Therefore, the anesthetist 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 a great reluctance to switch from "business as usual" to "emergency mode" even when serious problems were detected.

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In addition to the attentional demands of the anesthetist's core tasks, the OR environment is full of distractions. Routine events, such as turning the OR table or repositioning the patient, distract attention from the main process of conducting the anesthetic. Noise is prevalent, with peak levels exceeding that of a freeway.^{[164] [165]} Practitioners find false auditory alarms from monitors or other equipment to be extremely distracting.^{[166] [167] [168] [169] [170]} Other distractions include teaching in progress,^[163] incoming telephone calls, background music, and conversation with OR personnel. Expert anesthetists modulate the distractions, eliminating them when the workload is high while allowing them to occur when workload is low (in order to improve morale and team building).

Active Management of Workload

One major aspect of strategic control of attention is the active management of workload. Rather than passively dealing with rising or falling workload, the anesthetist actively manages it. Schneider and Detweiler^[171] and Gopher (position paper, Conference on Human Error in Anesthesia, Asilomar, CA, 1991) described the theoretical basis for a variety of strategies of workload management. These strategies have been addressed specifically for anesthesiology by several investigators.^{[63] [66] [67] [69]} The anesthetist actively manages workload by the following techniques.

1. Avoiding high workload situations

Experts may choose techniques and plans that reduce the workload (especially when their individual and team resources are limited), even when those plans are marginally inferior from a technical standpoint. For example, a single anesthetist may choose not to use a high-technology, high-workload monitor such as transesophageal echocardiography (TEE) because of the high workload required to use it properly.

2. Distributing workload over time

The anesthetist 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 intravenous infusions, are often made ready before the case starts. Multitasking is also a way to distribute work over time. Each task is 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 be interleaved with a fixed amount of attention (multiplexing). Multiplexed tasks must be scheduled and coordinated in real time at the supervisory control level.

3. Distributing workload over personnel

When workload cannot be distributed over time and when additional resources are available, tasks can be distributed to them. Some resources are internal to the individual anesthetist, whereas others require additional personnel. For example, a single anesthetist can simultaneously ventilate the patient by hand, assess the cardiac rhythm, and discuss patient care with the surgeon. The single anesthetist cannot simultaneously insert a pulmonary artery catheter and ventilate the patient's lungs by hand. If these tasks are to be performed at the same time, they must be assigned to different individuals.

4. Changing the nature of the task

The nature of a task is not fixed. Surgery and anesthesia can sometimes be postponed or aborted. Tasks can be executed to different standards of performance; as the standards are loosened, the workload required to perform them is reduced. For example, during periods of massive blood loss, the anesthetist focuses primarily on administering blood and fluids and on monitoring the blood pressure. In such cases, less critical tasks such as writing on the anesthesia record are offloaded to lessen the workload. The acceptable limits of blood pressure will also be widened.

Action Selection and Scheduling

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. Simulator experiments have shown that anesthetists sometimes have difficulty in selecting, planning, and scheduling actions optimally. The anesthetist must consider the following factors:

1. Preconditions are necessary for carrying out the actions (e.g., it is impossible to measure a thermodilution

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   cardiac output if there is no pulmonary artery catheter in place).
2. Constraints are placed on the proposed actions (some actions are incompatible with other aspects of the situation; e.g., it is impossible to check the diameter of the pupils when the head is fully draped in the surgical field).
3. Side effects of the proposed actions often play a controlling role in choosing among possible drug therapies.
4. Rapidity and ease of implementation of proposed actions are factors; those that are easily and rapidly performed are preferred over those that require more time, attention, and skill.
5. Certainty of success of the actions is often traded off against rapidity and ease of implementation (under some circumstances, the higher certainty of success of a set of actions justifies the investment of time, attention, and resources needed to implement them).
6. Reversibility of the action and the cost of being wrong are considered, with rapidly reversible actions preferred over those that cannot be reversed, especially when potential side effects are significant.
7. Cost of the action in terms of attention, resources, and money is taken into account.

Experts in other complex, dynamic domains (specifically tank commanders and fire chiefs) have been observed^[83] to conduct a mental simulation of the actions they are contemplating to determine whether there are hidden flaws in their plans. Anesthetists have been observed^{[63] [69] [70]} to rehearse a plan mentally in advance of a case, but the degree to which this is done in real time is not known. Because most actions can be executed incrementally, as in titrating a drug in small aliquots; adverse consequences can often be discovered through repetitive reevaluation.

Resource Management

The ability of the anesthetist to command and control all the resources at hand to execute the anesthetic regimen as planned and to respond to problems that arise is termed resource management (another concept first described in aviation that applies equally well to anesthesiology). This involves translating the knowledge of what needs to be done into effective team activity, taking into account the limitations of the complex and ill-structured OR, PACU, or ICU domain. Resource management explicitly requires teamwork and crew coordination. It is not enough for the anesthetist to know what to do or even to be able to do each task alone. The anesthetist can only accomplish so much in a given time, and there are some tasks that can only be performed by other skilled personnel (e.g., laboratory tests, taking radiographs). When the task load exceeds the resources available, the anesthetist must mobilize help and must distribute the tasks among those present. Many issues concerning optimum resource management and crew coordination are not yet well understood and are the focus of active research by cognitive scientists and experts in many complex and dynamic domains.^{[37] [38] [94] [172] [173] [174] [175] [176] [177] [178] [179]} Research in aviation has already demonstrated that a large proportion of aircraft accidents were linked to failures on the part of crews with appropriate technical skills to manage the flight deck effectively. ^{[84] [114] [180] [181] [182] [196]} The hallmarks of resource management derived from these studies is discussed in detail in Chapter 84 and include the following:

1. Knowing the environment
2. Anticipation and planning
3. Calling for help early
4. Exercising leadership (and followership)
5. Distribution of workload
6. Mobilization and use of all available resources
7. Effective communication
8. Monitoring, cross-checking, and utilization of all available data
9. Prevention and management of fixation errors
10. Reevaluation and use of cognitive aids
11. Effective teamwork
12. Wise allocation of attention
13. Dynamic prioritization of tasks

Complex multiple personnel simulations of anesthetic crises addressed these issues. Although the data from these sessions are still preliminary, it appears that poor supervisory control and resource management were substantial components of suboptimal management of the simulated crises.^{[133] [134]} In other words, like the pilots, anesthetists had the knowledge and technical skill to manage the patient, but they failed to manage their environment properly to achieve success. (In aviation, such situations have often resulted in what is called "controlled flight into terrain")

Resource management is now taught systematically to crew members of all major U.S. airlines through training programs in Crew (originally "cockpit") Resource Management (CRM).^[191]

A similar program in anesthesiology was first developed by Gaba and Howard and associates in Stanford^{[132] [138]} and has since been adopted by training centers worldwide. A detailed description of the Anesthesia Crisis Resource Management (ACRM) course is provided in Chapter 84 . A review of CRM in medicine was published by Davies.^[183]