Pediatric Informatics: Computer Applications in Child Health (Health ...

29 Understanding and Preventing Errors 371
In defining the event to be analyzed (i.e. what happened), it is important to
capture in chronologic order the sequence of events as well as the prevailing conditions.
It is also important to develop a picture of the event that does not include
assigning blame or causation which could bias the RCA process.
At the surface, RCAs are intended to dig beyond the most readily imaginable
cause. In its simplest form, RCAs ask “why.” Taichi Ohno, the person credited
with developing Toyota Motor Company’s revolutionary approaches to quality
management, 4 proposed asking “why” five times (“5 whys”) in order to uncover
the causes beneath the cause. The questions can continue until either the results are
beyond control, trivial, or unknowable.
As an example of applying the 5 Why approach, consider the hypothetical case
of a child exposed to a 50-fold excess rate of morphine infusion with resultant
hypoventilation and hypoxemia. Why did this occur? At first consideration, it might
have appeared to occur because the patient’s nurse loaded a Patient-controlledanalgesia
pump with a 50-fold higher concentration of narcotic but did not adjust
the infusion rate used to infuse the drug cassette that had just completed infusing.
Such an occurrence could be viewed as an error. However, we might ask, why did
the drug infusion proceed without interception by the standard operating procedure
requiring double checking process? We could find that double checking did not
occur. Why? Because there might be a culture tolerating deviations from the procedure
and it has been common to omit double checks. Alternatively, a second nurse
might not have been available and there might have been considerable pressure
to complete the task quickly to alleviate the patient’s discomfort. We might also
ask why the nurse selected the wrong drug cassette from the automatic dispensing
device that supplied the medication on the patient care unit. We could find that she
had been forced to make a selection of two solutions when the machine should
have only offered the correct cassette. Why might the two solutions have been
offered? They could have been offered because the patient’s order had expired and
no drug order had been dispatched to the dispensing device requiring the nurse to
override the normal checks and balances in the system. Why might the order have
been allowed to expire? It could have expired because no systems existed to alert
the physician, nurse, or pharmacist that expiration was imminent. This would be
consistent with the existing practice of reordering only after an infusing medication
cassette became empty.
In examining the example above, one can see that, were we to be satisfied with
the explanation that the dosing failure resulted from “nurse error,” we might be
satisfied to censure or retrain the offender. Had we stopped there, we might have
done nothing to alter the underlying factors that created the conditions under which
the nurse could err. Having delved further, we can identify a number of strategies
that could reduce the likelihood of future failure such as; increasing accountability
for double checking, procedures to prevent order expiration and stock-outs in the
dispensing devices that force workarounds, and automatic systems to intercept
dosing errors.
The Five-Why tool is consistent with what Gano has termed the “Cause and
Effect Principle” 5 which says that causes and effects are one and the same: the cause
of one effect is typically the effect of another cause earlier in a chain of causation.