Patient Safety, Potential Adverse Drug Events, and Medical Device Design: A Human Factors Engineering Approach

Abstract

Adverse drug events are the single leading threat to patient safety. Human factors engineering has been repeatedly proposed, but largely untested, as the key to improving patient safety. The value of this approach was investigated in the context of a commercially available patient-controlled analgesia device that has been linked with several alleged patient injuries and deaths. Several reports have stated that errors in programming drug concentration were made during these adverse drug events. A simulation of the commercially available interface was compared experimentally with a simulated prototype of a new interface designed according to a human factors process. Professional nurses, averaging over 5 years of clinical experience with the commercially available interface and only minimal experience with the new interface, programmed both interfaces. The new interface eliminated drug concentration errors, whereas the simulated commercially available interface did not. Also, the new interface led to significantly fewer total errors and faster performance. These findings may have broad implications for the design, regulation, and procurement of biomedical devices, products, or systems that improve patient safety in clinical settings.

Morphine overdose from error propagation on an acute pain service

“…22,23 As shown in the Table, this case demonstrated six of 17 potential errors associated with the PCA pump. While there was no actual transfer of patient care, the settings were not appropriately reviewed at the time of initiation.…”

“…Although the machine has a "four-hour limit", the incorrect programming in this case would negate this limit check on the machine since the machine would assume the 30 mL syringe contained only 15 mg of morphine, instead of the contained drug mass of 150 mg. A human factors engineering approach to designing the programming interface has been shown to reduce programming errors. 22 In addition, the implementation of bar code technology promises to further reduce the risk of programming errors. 24 Neither of the two nurses involved in the initial programming was familiar with the programming of these pumps.…”

Programming errors contribute to death from patient-controlled analgesia: case report and estimate of probability

“…The commonality in these cases is important; recent laboratory research shows that redesigning the programming interface for this particular device may virtually eliminate concentration programming errors. 20 It is well known that voluntary and mandatory reporting systems for adverse events and ADE, including the FDA MDR database, suffer from severe underreporting; epidemiological studies revealed reporting rates that ranged from a low of 1.2% to a high of 7.7%. 2, [21][22][23] We used these extreme values to transform the minimum and maximum reported frequencies in Table I into evidence-based high and low estimates of the true incidence of patient mortality associated with programming errors with this device.…”

“…First and foremost, user interfaces for PCA pumps should be redesigned to make them easier to program based on human factors engineering techniques. 20 Second, caregivers should always report any difficulty, near miss, injury, or death associated with PCA pumps and other medical devices using Health Canada's Medical Devices Problem Report Form so that the true magnitude of the problem can be established. The required form is easy to fill out and can be found on the internet (www.hc-sc.gc.ca/hpfb/inspectorate/md_pro_rep_form_tc_e.html).…”

Programming errors from patient-controlled analgesia

“…[2][3][4] [3] False triggering, for example, due to a short circuit in the PCA button 5 or for other reasons. 6,7 [4] False triggering by proxy (e.g., relatives pushing the PCA button because Granny is too sleepy to do it herself).…”