cause of ADEs among both physicians and nurses. At the level of physician ordering, lack of awareness of drug interactions and correct dosing was the most frequent problem; at the nurse level, during administration of medications, overdosing of anti-emetics, mixing drugs in incompatible solutions, and overly rapid infusion of intravenous drugs were the most common errors (Leape et al., 1995).
Mathematical proficiency is a prerequisite for accurately performing many aspects of medication administration, such as intravenous regulation (Ashby, 1997; Calliari, 1995). Nurses’ poor mathematical and drug calculation skills have been linked to medication errors (Bindler and Bayne, 1991; O’Shea, 1999). Yet experts in human factors and ergonomics estimate that humans will normally (under conditions that do not involve any time pressures or stresses) make simple arithmetic errors at a rate of 3 per 100 calculations (Park, 1997). When nurses must calculate drug dosages under conditions of stress or time constraints, it is likely that this error rate will be higher.
Other causes of ADEs include stresses in the environment, including interruptions, fatigue, and overwork; miscommunication, including illegibility of written drug orders; lack of information about the patient; and problems with infusion pumps and IV delivery (Pape, 2001).
Potential remedies A number of strategies have been proposed to address the above problems, including ongoing in-service education, use of reference material as decision support, and medication administration assistance devices. The Institute for Safe Medication Practices and AHRQ have identified three medication administration technologies (in addition to computerized prescriber order entry at the point of prescribing) as important strategies for reducing medication errors at the point of medication administration by nurses: unit dose dispensing, bar-coding of medications, and use of “smart” infusion pumps.7
Murray (2001) also examined automated medication dispensing systems—drug storage or cabinet dispensing systems that allow nurses to obtain medications at the point of use (some at the bedside) by electronically dispensing the medications at a specified time and tracking their use. However, Murray found that the “limited number of available, generally poor quality studies does not suggest that automated dispensing devices reduce medication errors.” Studies of their use observed: nurses waiting at busy administration times, removal of doses ahead of time to circumvent the waiting periods, and overriding of the device when a dose was needed quickly. The author cites these incidents as examples of “an often-raised point with the introduction of new technologies, namely that the latest innovations are not a solution for inadequate or faulty processes or procedures” (Murray 2001:114). This caution echoes a warning by the Institute for Safe Medication Practices that health care systems should “not place sole emphasis, resources, or reliance on automation while sacrificing or ignoring other safety initiatives … automation alone is not the panacea for medication errors that some believe it to be” (Anonymous, 2000).