It 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 homicideÛ 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 at trial.⁵

When 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

A system 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

Psychologists would 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.

Cognitive 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.

In the 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.

The problem-solving 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.

Various physiological 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 mistakes.¹

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.

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 In 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

The primary objective of any system review is to identify those latent errorsÛ 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 system fails.⁴

Effective 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

Leape, et al, have identified a number of "proximal causes" of medication errors. Proximal causes are defined as "the apparent 'reason' the error was made."² Proximal causes are broad categories where the underlying system problems that result in medication errors may be found.

By grouping proximal causes into broad categories, they become a useful means of focusing further inquiry, but they are not the true cause of errors.²

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 congenital syphilis.

In 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.

Congenital syphilis 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 death.

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 recommendation.

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 zeros.

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.