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

350 S.H. Mitchell et al.
27.3.3.1 Checking Doses Based on Allowed Dose Ranges
Robust dose-checking functionality should be considered a mandatory safety
feature for any PharmIS, especially if it is intended for use at a health-system caring
for pediatric patients. Common dosing errors include decimal errors (10-, 100-, or
1,000-fold errors) and other miscalculations. More sophisticated dose checking
may include considerations of renal and hepatic function according to known serum
drug levels or cumulative (lifetime) doses of specific medications (such as in cancer
chemotherapy). Currently most advanced functionalities are not widely available in
machine-usable forms.
Most PharmIS require the final ordered dose to be entered, either manually or
via a CPOE system, into its database to support operations (labeling, billing, etc.)
and for dose range checking. The mathematical calculations (i.e. dose per kilogram
or Body Surface Area (BSA) single and/or total daily dose) require access to the
appropriate data (such as weight, height, and age).
An ideal pediatric PharmIS should allow configuration for dose range calculations
(such as for BSA, which requires both weight and height) to use published
algorithms or to individualize algorithms for a specific institution (such as when
consensus is lacking 6 particularly in pediatrics). Appropriate dose check values for
any specific medication may also vary by administration route, and therefore, the
ability to vary these, either in user built data or through a configurable CDS system,
is desirable.
Some dose checking features may be configured directly within the PharmIS
application itself and performed according to institution-defined limits, or by a
separate CDS system running in tandem with the PharmIS. The former will offer
more flexibility as it is dependent on users defining and configuring the rules. The
advantage of this customizability should not be underestimated. Alert fatigue, 7 a
pheno menon where users of a system begin to ignore alerts after the validity or
importance of previously viewed the alert warnings are felt to be minimal, can leave
even the most well-intentioned users vulnerable to missing significant alerts. The
drawback of institutional adjustment of alerts is the amount of labor and clinical
expertise that are required to develop and maintain optimum rates of alert response.
Interfacing of the PharmIS with a third party CDS system allows updating of
the CDS by subscription to a service. Such a service provides periodic (monthly,
quarterly, or semiannually) updates, based on peer-review and evidence. Although
maintaining the data in such a system is as simple as applying the provided update
disk, these systems do not typically offer local editing of content that may contribute
to alert “noise.”
In PharmIS that allow configurable dose checking rules, all personnel involved
must be familiar with the clinical and technical aspects of the configuration tool
and developed rules must be tested extensively before deployment. Systems vary in
design details and critical functionality may or may not be available. For pediatrics,
significant dose variations may exist for many drugs according to patient age or
weight. Such a situation might lead to conflicting rules such as allowable high dose
limits for one patient group that would be overdoses in another group (and would