1. Gaunt, Michael J. PharmD
  2. Johnston, Janet MSN, RN, JD
  3. Davis, Monica M. MSN, MBA, CRNP


Don't assume they're safe; correct design and use are crucial.


Article Content

The Pennsylvania Patient Safety Reporting System (PA-PSRS, pronounced "PAY-sirs") is a confidential, statewide, Internet-based reporting system to which all hospitals, outpatient-surgery facilities, birthing centers, and some abortion facilities must file information on medical error.


Pennsylvania is the only state to require reporting of not only "serious events" (its Medical Care Availability and Reduction of Error Act of 2002 defines these as adverse events that result in death or unanticipated injury requiring the delivery of additional health care services) but also "incidents" (near misses). More than 500,000 reports have been submitted since PA-PSRS was implemented in 2004. Analysis of the reports has identified timely patient safety issues for the PA-PSRS Patient Safety Advisory, a quarterly publication that addresses high-volume issues, emerging trends, and unusual adverse events. In the Advisory, PA-PSRS presents evidence-based strategies for reducing risk, clinical analyses by program staff with expertise in patient safety, and successful approaches implemented by Pennsylvania health care facilities.


Patient safety is an often-examined topic of nursing research. But researchers' recommendations can require significant changes to policies and procedures; these changes can take considerable time and effort to implement and may be resisted by staff or administrators. Safety Monitor, a new column in AJN from PA-PSRS, will inform nurses of issues that can affect patient safety and present strategies that they can easily integrate into practice.


For more information about PA-PSRS, visit the Web site of Pennsylvania's Patient Safety Authority, at For the original articles discussed in this column or for other articles on patient safety, click on "Advisories and Related Resources" in the left-hand navigation menu.


Hospitals have embraced the use of automated dispensing cabinets (ADCs) to provide timely access to medications. By 2005, 72% of hospitals in a national survey reported that they were using this technology to control the storage and documentation of medications in patient care areas.1 ADCs have improved safety in narcotic storage, streamlined common tasks for nurses and pharmacists, and reduced costs by eliminating the need for patient-specific cassettes. But a number of issues related to their use and implementation have surfaced. In fact, ADCs are the source of the medication in almost 15% of reports of medication error that PA-PSRS has received. Several factors contribute to the errors.



Even ADCs that require the pharmacy to review drug orders prior to allowing access to the drug have an override feature permitting emergency access. The override function may be misused because of inefficiencies in the system, such as lengthy waits for pharmacy order review, inadequate training of personnel in using the ADC, and lack of guidance about what is considered an emergency. These work-arounds have led to medication errors, such as administration of the wrong drug, the wrong dosage, or a drug to which the patient has a documented allergy. The following two PA-PSRS reports are examples of errors resulting from work-arounds:


* Zosyn (piperacillin and tazobactam) was ordered for a patient. The first dose was given in the ED and a second was given on the medical unit. Before review by the pharmacy both doses were retrieved from an ADC. When the pharmacy reviewed the order, they discovered that this patient had a documented allergy to penicillin. The patient experienced no adverse reactions.


* A stat dose of morphine was ordered for a patient who had a documented allergy to this drug. A pharmacist caught the error and contacted the physician, but the nurse had already engaged the override function on the ADC to remove the morphine and administer it to the patient. No adverse reactions were noted in the report.



Confirmation bias

People tend to see what they expect to see. This tendency, sometimes called confirmation bias, can lead to a number of errors in the use of ADCs.


Alphabetic drug pick lists, for example, though a convenient feature of ADCs, can contribute to errors if the clinician selects a drug with a similar spelling to that of the correct drug. However, if the ADC requires pharmacy review before drugs can be retrieved, it will alert the nurse and prevent access to the wrong drug.


Similar errors may result if look-alike drugs are stored in a bin in the same drawer. Nurses may confuse products with similar packaging and choose the wrong drug because they "see" what they expect to see instead of noticing what is actually there. Confirmation bias-when a person notices only what confirms preconceptions-may also affect ADC stocking. For example, the pharmacy technician may select the right drug but place it in the wrong drawer. The following PA-PSRS reports show how confirmation bias may have played a role in the confusion of look-alike drugs hydroxyzine (Vistaril) and hydralazine (Apresoline), and hydromorphone (Dilaudid) and morphine (Astramorph, Duramorph).


* A prescriber ordered hydromorphone 0.5 mg IV for a patient. But both morphine and hydromorphone were available when the ADC drawer was opened. The practitioner selected and administered morphine to the patient by mistake. The patient was not harmed.


* A nurse took a verbal order from a physician for hydroxyzine 25 mg IM every three hours as needed for itching and correctly documented the order in the patient's chart. But when she went to the ADC, she chose hydralazine and administered 25 mg IM to the patient, which resulted in a significant drop in blood pressure.




Here are some suggestions to ensure the safe use of ADCs2:


* Select ADCs with systems that support patient medication profiles and bar coding.


* Implement bar-code-scanning technology with the ADC to verify that the right drug is stocked in the right bin. If the cabinet does not support this technology, implement a manual double-check process to verify accurate ADC stocking; this may be as important as the pharmacy's double-check process to verify that the correct drug has been pulled from the pharmacy shelf before dispensing it to the patient care area.3


* Ensure that a pharmacist screens all new medication orders before the drug is administered, reviewing the drug, dosage, frequency and route of administration; allergies; interactions with other medications or foods; and laboratory values. This is particularly important for high-alert medications stored in ADCs. (You can find a list of high-alert medications at


* Avoid storing large volumes of medications or bulk supplies such as multidose vials in ADCs.


* Store adult and pediatric medications in separate drawers or cabinets.


* Use labels or screen alerts to identify allergy risks for medications such as antibiotics, opioids, and nonsteroidal antiinflammatory drugs.


* Limit the use of the override function to emergency situations.


* Remove one dose at a time.


* Report potential storage problems that may lead to errors, such as drugs that look alike or sound alike being placed near one another.


* Inspect any medication you remove from the ADC, and contact the pharmacy if the medication looks different from the last time you administered it.


* Regularly review the ADC inventory to be certain it matches the needs of the specific unit, taking into account patient ages and diagnoses, and recommend changes when necessary.


* Work closely with the pharmacy to ensure the safe use of ADCs.





1. Pedersen CA, et al. ASHP national survey of pharmacy practice in hospital settings: dispensing and administration-2005. Am J Health Syst Pharm 2006;63(4):327-45. [Context Link]


2. Placing limits on drug inventory minimizes errors with automated dispensing equipment. ISMP Medication Safety Alert, Acute Care Edition 1998;3(24):24. [Context Link]


3. Look-alike names and packages are at the root of most stocking errors in automated dispensing cabinets. ISMP Medication Safety Alert, Acute Care Edition 2003;8(3):3. [Context Link]