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

380 M. Apkon
Although it is tempting to define countermeasures effective against each of these
contributors, the team recognized that different failures occurred with different likelihoods.
Moreover some failures are potentially detectable as in calculation errors
that are found on double-check whereas other failures are undetectable as in placing
an incorrect mass of medication into the diluent solution. It was also important to
recognize that the two failure modes were not equivalent in severity: it was thought
to be more dangerous to infuse the medication at the wrong dose compared to the
correct dose at too high a fluid administration rate.
Recognizing that a redesigned infusion process would need to be compared
against the existing process, the team conducted a FMEA to characterize the
riskiness of the original and improved infusion processes. The FMEA takes into
account differences in likelihood of failure, ease of detection, and the severity of the
consequences of failure. The FMEA identified three risky elements of the original
infusion process: calculating the required formulation; preparing the formulation
by combining drug and diluent; and programming the infusion pump, particularly
at the time of dose changes. It is important to note that although mistakes in preparing
the infusion solution are likely less common than calculation errors, preparation
errors are considered riskier in this analysis because they are not detectable after they
are committed whereas calculation errors can be detected by double-checking.
A number of improvements were identified to reduce the risk of these processes.
It is useful to consider these improvements in the framework of the error-proofing
strategies described above. The task of formulation was eliminated entirely for
some infusions by purchasing premanufactured solutions. This required a change
from formulations being defined at the point of care to being standardized with
fixed concentrations of medications. Formulations were also eliminated by increasing
the “hang-time” of the solutions thereby reducing the number of solutions
formulated over a course of therapy.
The functions of “action” required to formulate solution in the more error-prone
environment of the bedside was replaced by formulation in a central pharmacy by
dedicated staff specifically trained to the task. The functions of judgment as to the
correct rates of fluid administration were replaced as part of standardizing concentrations
because the standards were designed to allow appropriate fluid administration
rates. The functions of “action” required to calculate the solution formulations
were enhanced by a set of readily accessible internet-based calculators which drew
from the standard concentration library.
Detection of errors was also enhanced by having the calculators print out a
spreadsheet intended to be placed at the bedside which presented a set of dose/
infusion-rate combinations. This is intended in part to enhance the ability to
identify errors in pump programming. In addition, standardization itself makes
detection of anomalous prescriptions easier.
Together, these improvements reduced the riskiness of the infusion delivery
process considerably. The ability to prospectively model the impact of these
improvements was helpful in communicating the need for radical changes in practice
including the need to standardize and give up individual autonomy in deciding
how to formulate infusions.