Human Factors and Medical Devices (continued)
Subchapter 41.3. Equipment Checklists in
Events related to medical equipment can be divided into two
categories, user-error and equipment failure.43 Health device
inspection and preventive maintenance by biomedical or clinical engineering
departments have high face validity as an important patient safety practice in
reducing equipment failure.
There are many calls in the engineering literature to
standardize equipment maintenance.44-46,46 Standardization of
protocols is believed to help make the processes more efficient and reduce
errors.47 However, it has been difficult to standardize equipment
maintenance practices due to a lack of the appropriate units on which to base
measurement.46 Some authorities have suggested outcomes based on
engineering endpoints such as reliability and accuracy.48 Others have
tried to validate a set of maintenance outcome units based on cost or quality
metrics.44,45,49 Some engineers have suggested the incorporation of
clinical endpoints into medical equipment assessment.48,50
Notwithstanding differing views as to measurement of endpoints, experts
uniformly believe that standardization of engineering endpoints is vital to
ensure adequately inspected and maintained equipment.46 No studies to
date have developed a widely used standardized protocol for equipment
maintenance for clinical engineering departments, largely because the lack of
standardization of endpoints renders assessing the relative value of any
particular maintenance protocol impossible.44-46,48,50 Nonetheless,
equipment failure does result in a small fraction of clinical events and thus is
an important safety intervention. Hopefully, future studies will help delineate
the most effective practices for equipment maintenance processes.
Use of checklists is another practice that helps ensure
equipment readiness, particularly for equipment that is needed in critical
situations and/or where equipment failure may have dire consequences. For
example, a nurse at the beginning of each shift may use a checklist to ensure
the readiness of a hospital ward's resuscitation cart ("crash cart") should it
be needed (e.g., the defibrillator is plugged-in and charged, the back-up suction
pump works, medication is not past its expiration date). Similarly, a perfusion
technologist can use a checklist to ensure cardiac bypass circuit and back-up
equipment are ready before surgery. Published studies on the effectiveness of
equipment checklists largely relate to the use of preoperative checklists to
prevent anesthesia equipment failures since, to date, studies on the
effectiveness of equipment checklists in medicine have been limited to this
area.51-53,54 These studies are reviewed in Chapter 23.
Final Comment to Chapter
Human factors testing is yielding important data regarding safe
and effective medical device and alarm designs that take into account the users'
cognitive limitations. Machines can be designed and redesigned that enhance
patient safety, rather than compromise it.
Currently, there are no widely accepted standards for equipment
maintenance intervals and protocols. Maintenance endpoints that incorporate
clinical events as one component of the endpoint have been suggested. Until a
reliable and validated engineering endpoint metric is widely recognized it will
remain difficult to investigate the most effective maintenance practices.
Other than the pioneering work in anesthesiology, HFE has been
underutilized in medicine. Hopefully, in the near future, more attention will be
focused on integrating human factors engineering within all aspects of medical
training and practice, which will help create a culture of safety.
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