improve clinical practice and quality of care by providing a learning
opportunity that enhances the participant's understanding of a systems
approach to medication errors and error prevention.
you have completed this course, you will be able to:
the situations, circumstances and actions that contributed to a fatal
medication error in one hospital.
systems, processes, and conditions that could contribute to errors
in any clinical environment.
was a tragedy that should never have happened. A newborn infant was given
a tenfold overdose of the intramuscular (IM) medication penicillin G benzathine
by intravenous (IV) route that resulted in his death. The parents were
devastated at the loss of their child; the hospital staff was devastated
at the loss of their patient. But the devastation did not stop there.
As a result of the medication error and subsequent death, three nurses
were indicted on charges of negligent homicide█ the first time that nurses
had faced criminal charges for a medication error in this country.3
In January 1998, two of the nurses plead guilty in response to a plea
bargain; the third nurse, who refused the plea bargain, was acquitted
an error as traumatic as this occurs, it is only natural to want to
find the person "who did it," assign them responsibility, and impose
some punishment. With the finger-pointing approach, the most proximal
cause of the error is generally the one that bears the burden of blame.
Unfortunately, this approach does not take into account that most medication
errors occur, not as a result of a single act by a single individual,
but as a result of multiple, cascading events compounding one another
until a catastrophe happens. Most errors occur as a result of "a chain
of events set in motion by faulty system design that either induces
errors or makes them difficult to detect," rather than lack of care
and concern on the part of our caregivers.2
can be defined as "an interdependent group of items, people, or processes
with a common purpose."2
The systems approach to error management has been a fact of life in
aviation and nuclear power management for many years. When an air travel
incident occurs, the first question is not who caused the accident,
but what caused the accident. In medicine, the systems approach
has been slow to take hold. Perhaps it is because we don't want to believe
that physicians, nurses, and pharmacists are fallible. As professionals,
we are trained to believe that perfect performance is not only expected,
it is also achievable. That if we know enough, take enough care, and
try hard enough, our patients will be safe and protected. As Lucian
Leape, author of "Errors in Medicine" noted, the result is that we come
to view error as a failure of character.1
call this a false belief because the reality is that no matter how knowledgeable,
no matter how careful, no matter how hard we try, human beings make
errors! Systems that rely on error-free performance are doomed to failure.
Once we recognize that fact, we have a much more powerful mechanism
for discovering the real cause of catastrophic errors and preventing
them in the future.
psychologists and human-factors specialists have been studying how and
why people make errors for many years. Cognitive psychology has to do
with how human beings think. Human-factors specialists deal with the
man-machine interface in complex environments.1
Their work in airplane cockpits and in nuclear power plant control rooms
can serve as a helpful model to healthcare in redesigning systems to
reduce errors. Very simply, they have found that there are two modes
of mental functioning: automatic and problem solving.
automatic mode, mental processes are fast and effortless. We really
don't have to "think" in this mode, our actions are unconscious and
require our attention only if there is a change. This automatic mode
is possible because human beings are able to carry a vast array of mental
models that are expert and fine-tuned processes for some minute recurrent
aspect of our world.1
Once we have a task "down," it becomes a part of automatic mode thinking.
mode, on the other hand, may require intense mental concentration. We
have to gather information and compare it to stored knowledge, or apply
some decision rule, in order to know how to act. As a result, problem-solving
processes are much slower, sequential, effortful and difficult to sustain.1
The errors that occur
when we are functioning in these two mental modes are also different.
When we are functioning in automatic mode, our errors are called "slips"
in that they usually result from distractions or failure to pay attention
at critical moments. An example of an error in automatic mode would be
walking into a room only to discover you cannot remember what you came
in to do.
Errors that occur
when we are functioning in problem-solving mode are thought of as "mistakes."
These are rules-based errors that might occur when the wrong rule is chosen,
either because we have misperceived the situation, or perhaps because
we just misapplied a rule. Errors can also arise when we have gaps in
our knowledge base, especially when we are confronted with an unfamiliar
situation for which we have no programmed solution. Other factors that
effect our functioning in problem-solving mode are pattern matching, biased
memory, the availability heuristic, confirmation bias, and overconfidence.
Pattern matching is the tendency to find patterns in situations
so we can apply previously thought out solutions. Biased memory
is the tendency to over-generalize because familiar patterns are assumed
to have universal applicability. The availability heuristic is
the tendency to use the first information that comes to mind. Confirmation
bias is the tendency to look for evidence that supports early working
hypotheses and ignore new information that contradicts it. And overconfidence
is the tendency to believe in the validity of the chosen course of action
and to favor evidence that supports it.2
All of these factors effect our problem-solving ability.
and psychological factors can contribute to inattention and distraction
and can play a part in both automatic mode errors and problem-solving
mode errors. Physiological factors include fatigue, sleep loss, alcohol,
drugs, and illness. Psychological factors include distraction due to
other activity ("busyness"), as well as emotional states such as boredom,
anger, fear, and anxiety. Psychological factors can be triggered by
external factors such as overwork, interpersonal relations, and other
forms of stress. Environmental factors such as noise, heat, motion,
and visual stimuli can also divert our attention and lead to slips and/or
While an appreciation
for the psychological and physiological factors that contribute to errors
is useful in understanding that errors are an essential part of being
human, they provide limited insight into ways of avoiding or preventing
errors. That is where a systems approach it most beneficial. We know that
human beings will naturally have "slips" and make "mistakes." Systems
research and the work of human-factors specialists inform us that certain
aspects of our systems can either add to the likelihood of error occurring,
or act as a fail-safe to prevent errors.
can be termed active or latent. An active error is one
whose effect is immediate. For instance, turning left against on-coming
traffic has an immediate effect. Either you are hit broadside, or just
avoid a collision. Latent errors are those situations or errors whose
effects are delayed - the proverbial "accident waiting to happen."4
our left turn example, perhaps the intersection is poorly controlled,
or trees or a curve in the roadway impair the visibility. As a result,
every time a driver needs to make a left turn, the potential for disaster
is high. Accidents rarely result from a single error, latent or active.1
objective of any system review is to identify those latent errors█
accidents waiting to happen, and redesign or alter the system to recognize
and correct the error before it happens. If it is not possible to prevent
an error from happening, the next best alternative is a system that
self-corrects when an error is detected. And if a self-correcting system
is impossible, systems should be designed to detect errors and surface
them as soon as possible so remediation can start. This requires that
systems be designed with feedback and monitoring mechanisms as an integral
part of the system. In the case of critical mechanisms and processes,
redundancy should be built in to compensate in the event the primary
accident and error prevention focuses on root causes - errors in the
system design and implementation, not on the errors themselves or the
individuals making them. In order to do that, certain principles should
be followed. For instance, tasks should be simplified. "Forcing functions"
should be integrated that make it impossible to act without meeting
a precondition. And processes should be standardized to reduce variability
and reinforce pattern matching.1
et al, have identified a number of "proximal causes" of medication errors.
Proximal causes are defined as "the apparent 'reason' the error was
Proximal causes are broad categories where the underlying system problems
that result in medication errors may be found.
proximal causes into broad categories, they become a useful means of
focusing further inquiry, but they are not the true cause of errors.2
the facts of this case, as presented in this section, were taken
entirely from Smetzer, Judy L. "Beyond Blaming Individuals: Lesson
from Colorado," Nursing98 (May 1998).
case that follows is not unlike many incidents involving medication errors.
A number of factors contributed to the creation of a complex series of
events. And while you may want to assign blame to one or more of the parties,
try to suspend that impulse and look for the systems failures - the proximal
As you proceed through
this case, we will provide you with information about the incident cited
at the beginning of this article. You will have an opportunity to give
your opinion about the type of system failures that may have contributed
to the medication error and compare your responses to those of all other
individuals taking this course. At the end is a test. If you are taking
this course for continuing education credit, click on the Exam button
to complete the test and submit your answers.
Miguel Sanchez was
born on October 15, 1996, a healthy, 7 pound (3.2 kg) male infant. Shortly
after his birth, the hospital staff became aware that his mother had
a history of syphilis. It was unclear from the mother's prenatal record
when she had had the syphilis and whether or not it had been successfully
treated. Further complicating the situation was the fact that both parents
spoke only Spanish, and while translators were available, the staff
was still unable to determine whether the syphilis had been treated.
This caused the staff to have some concerns about the possibility of
addition to the inability to gather sufficient information about the
mother's medical history, the language barrier also presented some difficulty
in discussing treatment options. So, while there was no urgent clinical
reason to treat Miguel immediately, the neonatologist was not convinced
the parents understood the importance of follow-up. Therefore, the decision
was made to investigate the possibility of congenital syphilis in little
Miguel and treat him before discharge.
is rarely treated in the hospital and the staff was relatively unfamiliar
with it. The neonatologist called a local infectious-disease specialist
who recommended diagnostic studies including a lumbar puncture. The consultant
also recommended a single dose of penicillin G benzathine, IM, at a dose
of 50,000 units/kg. Unfortunately, the neonatologist did not document
the recommendation he had received until the following day, after Miguel's
Another staff member
called a health department epidemiologist who made the same recommendation.
She then documented the recommendation on the physician order sheet in
the space provided for progress notes. Unfortunately, her notation was
inaccurate. The note stated the health department had recommended "penicillin
G 50,000 units/kg" when in fact, the recommendation had been for "penicillin
G benzathine." She did not record the recommended route of administration
in her note. At the time of administration, this was the only documented
The day after Miguel
was born, a different neonatologist performed the lumbar puncture and
wrote an order for one dose of "Benzathine Pen G, 150,000 U IM". The physician's
written order was unusual in that instead of writing "penicillin G benzathine,"
he wrote "Pen G" on one line and placed "Benzathine" on the line above
"Pen G." Further confusing the order was the fact that the route, "IM"
appeared to be written over and looked somewhat like "IV". Also, "units"
was abbreviated as "U," which could be easily misread as one or two additional
Remember, at this
point, the only documented recommendation was the one written by the staff
member who called the health department, and that was inaccurate.
When the order arrived
in the pharmacy, there was no pediatric pharmacist working. The pharmacist
on duty was also unfamiliar with the treatment for congenital syphilis
and she had little knowledge about this rarely used, non-formulary drug.
She reviewed the health department's recommendation (inaccurately documented
on the physician order in the progress note section) and Drug Facts
and Comparisons to determine the infant dose. Unfortunately, she misread
the dose in both sources as 500,000 units/kg rather than the correct
infant dose of 50,000 units/kg. She also misread the physician
order as 1,500,000 units instead of 150,000 units. Since
she was under the mistaken understanding that the correct infant dose
was 500,000 units/kg, it is easy to see how the pharmacist could have
misinterpreted the "U" as an extra zero, thus seeing 1,500,000 units on
When she entered the
tenfold overdose into the pharmacy computer system, the system did not
generate any warnings about exceeding the maximum dose for a neonate.
As a result, the pharmacist prepared an incorrect dose: 1,500,000 units.
Because the nursery
did not have a unit dose system, the pharmacist prepared two pre-filled
syringes of penicillin G benzathine, 1.2 million units/2 ml each. She
put green stickers on the plungers reading "Note dosage strength" to indicate
that the entire contents of the two syringes should not be administered.
The syringes were
placed in a plastic bag, and a label was affixed with directions to administer
2.5 ml of the medication IM to equal a dose of 1,500,000 units (one full
syringe and one-quarter of the other). The correct dose should have been
150,000 units/0.25 ml. No other warning labels were affixed to the drug
to alert the nursing staff that penicillin G benzathine should be administered
because she was not a pediatric pharmacist, the pharmacist was unaware
that a maximum volume of only 0.5 ml can be safely administered to an
infant per IM injection. If she had known that, the tenfold overdose might
have been detected at this point since the dose as dispensed was going
to require five separate injections.
After preparing the
medication, the pharmacist noticed that the medication in one of the pre-filled
syringes had expired. After replacing the syringe, another pharmacy staff
member dispensed the drug without checking it against the original order.
Once again, the tenfold overdose was missed.
After noting the order
for penicillin G benzathine, Miguel's primary care nurse and a neonatal
nurse practitioner researched the treatment of congenital syphilis by
consulting the 1994 Red Book: Report of the Committee on Infectious
Diseases. One drug recommended to treat congenital syphilis was penicillin
G benzathine IM. However, the source, which was not a specific drug reference,
did not warn that the drug could be administered IM only.
When the medication
was delivered to the nursery, the primary care nurse expressed concern
to her colleagues about the five injections Miguel would need. If the
drug had been dispensed correctly, just one IM injection of 0.25 ml (150,000
units) would have been needed. Hoping to prevent Miguel unnecessary pain,
an advanced-level nursery RN and the neonatal nurse practitioner decided
to investigate giving the drug IV instead of IM.
The two nurses consulted
Neofax '95 to determine if penicillin G benzathine could be administered
IV. The monograph did not specifically mention penicillin G benzathine.
Instead, it identified the treatment for congenital syphilis as aqueous
crystalline penicillin G by slow IV push or penicillin G procaine IM.
As a result of this
lack of specific reference to penicillin G benzathine, and being unfamiliar
with the various forms of penicillin G, the neonatal nurse practitioner
thought that "Benzathine" was a brand name for penicillin G. This misconception
was further reinforced by the unusual way the physician had written the
order: with "Benzathine" on the line above "Pen G." And since the health
department recommendation had been inaccurately recorded as just "penicillin
G" with no specified route of administration, the misconception continued.
In addition, many
sources use ambiguous synonyms when referring to different forms of penicillin.
Believing that "aqueous crystalline penicillin G" and "penicillin G benzathine"
were the same drug, the neonatal nurse practitioner concluded that the
drug could be safely administered IV rather than IM.
While hospital policy
did not clearly define the prescriptive authority of non-physicians, nurse
practitioners in this hospital routinely prescribed medications within
the scope of their practice. And in fact, routes of administration had
been changed by nurse practitioners before. The neonatal nurse practitioner
also thought she was acting under a national protocol that allows nurse
practitioners to plan, direct, implement, and change drug therapy. Consequently,
she decided to administer the drug IV.
While preparing to
give the medication, neither nurse noticed that the syringes were labeled
with a manufacturer's warning: "IM use only."
warning was not prominently placed and to view it, the nurse would have
to rotate the syringe 180 degrees away from the drug name. Also, once
the pre-filled syringe was assembled for use, the orange plunger concealed
part of the "M" in "IM" making it possible to misread the warning as "IV
use only." Once again, the tenfold overdose went undetected.
In addition to the
packaging problems, the manufacturer's labeling on the syringes, as well
as the pharmacy label, expressed the dose using multiple zeros: "1,200,000
units" and "1,500,000 units" rather than "1.2 million units" and "1.5
million units." Perhaps if the dose had been expressed thusly, the tenfold
overdose would have been detected, but it was not.
Penicillin G benzathine
is a white, milky substance. This might have caused the nurses to pause,
but they were also aware that some IV substances, such as lipids and other
lipid-based products, looked milky and still could be safely given IV.
So, even though this conflicted with the widely recognized rule that only
clear liquids should be given IV, the nurses did not recognize any problem
with giving penicillin G benzathine IV.
And so, believing
they were sparing the baby unnecessary pain, the nurses began to administer
the first syringe of the drug by slow IV push. After about 1.8 ml of the
medication had been administered, the infant became unresponsive. Resuscitation
efforts were unsuccessful and Miguel died.
As we mentioned before,
it is tempting to assign blame for this error to an individual, but it
is also clear that in this case, many individuals were involved with many
opportunities to detect the error. All the parties involved had to deal
with the tragic results of their mistakes, and since Miguel's death resulted
in criminal charges, the three nurses also had to deal with the additional
trauma of a criminal trial.
for the trial, the staff at the Institute of Safe Medication Practices
worked with the nurses' defense attorneys to perform an in-depth system
analysis of the medication error and provide expert testimony at trial.
As a result of that analysis, they identified over 50 different system
failures that allowed the error to develop, remain undetected, and ultimately,
reach this infant.5
Recall for a moment Leape,
Bates, and Cullen's list of proximal causes of medication errors. When we
review the major system failures in the Miguel Sanchez case, most of the
errors would fall into one of these categories. It is clear that if even
one of these failures had not occurred, the error would have been detected
and the baby would not have been harmed.
The systems approach can be a powerful framework in correcting existing
system failures and in identifying and remediating potential system failures.
It is up to us, the care providers, to stop blaming individuals for errors
and start looking at the root causes within our systems that are the true