Execution and Adaptation of Plans
Anesthetic plans are dynamic. The anesthetist must monitor the
plan as it is executed and must adapt it in response to dynamically changing events.
The key features
Figure 83-2
Schematic diagram of the dynamic adaptation of preoperative
plans. The anesthetist begins the anesthetic with an intravenous (IV) induction
as planned (top left). On achieving the milestone
of successful induction of anesthesia, the blood pressure (BP) is checked before
proceeding with laryngoscopy and intubation (center).
If the BP is not satisfactory, the next step may be delayed and the plan amended
to optimize the BP. If necessary, the case may even be aborted at this stage. Throughout
the case, the anesthetist is vigilant for the occurrence of new problems ("police
cars"). If a problem is detected, a process of reactive problem-solving
takes place, which may result in new adaptations to the plan (in this case, treatment
of bronchospasm). (From Gaba DM: Human error in dynamic medical environments.
Hillsdale, NJ, Lawrence Erlbaum, 1994, pp 197–224.)
of this task are (1) checking for the achievement of milestones and (2) reactive
plan adaptation. These are shown schematically in Figure
83-2
. At various points of a case, there are critical milestones that
must be achieved in order to keep the original plan unaltered. If a milestone is
not achieved, the anesthetist must decide whether to delay the next action in the
sequence, to modify the plan, or to suspend or abort the case. On some occasions,
the milestones are explicitly identified in advance, whereas in other cases, the
milestones are implicit.
The anesthetist must also react to a large number of other contingencies,
some of which can be predicted in advance, based on the patient's history and the
type of surgery, whereas others cannot be anticipated. Incoming data streams must
be constantly scrutinize (see the "police cars" in Fig.
83-2
), to determine whether an expected or unexpected contingency is occurring.
If so, the existing plan may have to be modified. As plans are changed, actions
may be taken that invalidate other aspects of the previous plan, requiring further
adaptation of the plan. In some cases, even the original goals of the anesthetic
plan may need to be adapted.
