Biomedical Engineering Reference
In-Depth Information
must look for ways to prevent and improve their envi-
ronment, to prevent mishaps from occurring. One
example of a relatively simple sounding task, but often
complicated by various factors for the OR team, is pa-
tient positioning. A number of injuries have occurred
because of positioning. Different departments must take
into account their own prospective needs. Surgeons must
have access to certain areas for sterile prep and the sur-
gical site. Nurses must make sure that the items for
which they are responsible are accessible and do not
cause potential pressure points, while anesthesiologists
are looking out for potential nerve injuries. Because the
patient is unconscious, he is unable to tell them that the
position is uncomfortable, and staying that way for 6
hours can hurt.
Anesthesia safety is frequently compared to flying an
airplane. On airplanes, most of the problems (and,
therefore, most hazards) are associated with take-off and
landing. In anesthesia, this is equivalent to induction and
emergence. Both have multiple systems working in
unison to maintain function. On a commercial plane,
fuel is delivered precisely to engines that are attached via
structural members to a fuselage, with a crew using RF
communication and a global positioning system to move
the plane from one location to another. During anes-
thesia, oxygen is mixed carefully with an inhaled anes-
thetic agent and delivered through a breathing circuit
driven by a ventilator, controlled by a physician who
watches a display to monitor electrical and physical
changes in a patient who cannot communicate. As long as
things are going well, everything appears to be relatively
simple.
Unfortunately, things do not always go as planned. A
number of factors can contribute to undesired events
during anesthesia, including noise, fatigue, and boredom.
Studies have shown that anesthesiologists can be idle
40-70% of the time during a surgical procedure (Drui
et al., 1973; Boquet et al., 1980), which could further
affect their vigilance at their primary responsibility of
monitoring the patient, procedure, and equipment.
When something out of the ordinary occurs and takes
anesthesiologists off their planned course, it can lead to
moments of high activity, where many things must be
accomplished in little time, potentially in a state of
concern. These periods are often associated with high
task density, where people average less time on in-
dividual tasks in contrast with the time spent during less
busy periods (Herndon et al., 1991). In both aviation
and anesthesia, there are lengthy, intensive training pe-
riods and highly educated and skilled personnel. Each
field relies on a person who has a widely varying work-
load, to maintain order. It does not take much time for
one or two additional missed warning signs to result
with significant demands on the individual at the con-
trols. For a pilot or an anesthesiologist, an uneventful
day is a good day. No one likes unpleasant surprises on
an airplane or in anesthesia.
Redundant systems help to prevent surprises. Studies
in the aviation industry show that adverse outcomes
frequently happen when a number of undetected
smaller events occur, involving different factors (e.g.,
human error, equipment failure, and supply mishaps)
cumulating in an undesired result (Billings and Reynard,
1984). There always should be additional resources for
people to turn to for help. This can be difficult for some,
because they may feel that asking for help shows
a weakness and that they should be able to figure it out
on their own, lest they be seen as less than fully capable.
Patient care environments must try to foster a setting in
which looking for help when an individual is not fully
comfortable with a condition is a perfectly respectable
option and not cause for punitive action. Solutions can
be relatively simple but not visible when an individual is
fixated on something else. Another viewpoint might be
all that is needed. Physicians frequently have enough to
worry about and might not always see the solution; this
state of affairs can be more prevalent at teaching in-
stitutions. CEs can back physicians up by understanding
the demands placed on them and on the clinical
environment.
To minimize the possibility of equipment failures
during use, the aviation industry implemented a preflight
inspection. Similarly, those who are concerned with an-
esthesia safety developed the United States Food and
Drug Administration (FDA) Anesthesia Apparatus
Check-out Recommendations (FDA, 1993). A team of
people of varied backgrounds and interests created the
FDA procedure. When followed correctly, this compre-
hensive procedure can identify almost any problem.
Although it is a simple procedure, it does require the user
to know proper technique. It can be simple to make
a mistake (e.g., negative pressure leak test with the ma-
chine turned on) that results in false positives or nega-
tives. Most anyone with a reasonable understanding of an
anesthesia machine can perform the checkout. A tech-
nician or engineer with more in-depth knowledge of the
components that are actually being tested can use it as
a useful troubleshooting tool to easily identify system
failures within the machine.
The aviation industry has used simulators for years.
Their use is expanding medicine to put physicians in stress-
ful situations without putting patients at risk. People need
to be taught crisis management. One needs to conceptualize
and understand how to work in a team when encountering
stressful and challenging situations. The human mind does
not function rationally when in a panic.
Safety at off-site locations is worth noting. A
number of undesired events have prompted review of
office-based anesthesia. The associated risk versus cost
is an example of the many challenges faced in health
