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Watch Where You Scan

Cheryl A. Thompson

Bar-code readers scan the wrong patient's identifier just as accurately as they scan the correct patient's, so watch where you point.

The Institute for Safe Medication Practices (ISMP) reports that a pharmacist, while processing a pile of medication orders, did not realize that the bar-code reader scanned the identifier on the order sheet directly underneath the top one. 

Once an identifier is read, the scanner program asks, "Correct patient?" On the busy evening in question, the pharmacist automatically pressed "Enter" to continue order entry but did not first compare the name on the order sheet with the name on the computer screen. The incorrect patient's medication profile appeared onscreen, and the pharmacist entered orders for metformin and glipizide. 

While the intended patient needed antidiabetic medication, the patient whose identifier had been scanned did not. 

On the care unit, a nurse noticed doses of metformin and glipizide in the bin for a patient whose medication administration record (MAR) did not list those drugs. The nurse called the pharmacy, whereupon a pharmacist checked the computerized profile and told the nurse that both drugs had been ordered for the patient. With the patient's chart unavailable, the nurse relied on the pharmacist's word. 

After the incorrect patient received metformin and glipizide for two days, hypoglycemia developed, leading to discovery of the medication error. The patient was treated and stabilized without further injury. 

Meanwhile, another nurse inquired as to the whereabouts of the missing antidiabetic medications. The pharmacist asked for a duplicate copy of the order but did not search the pharmacy to check whether the order had been received. 

In analyzing this case, ISMP noted that errors can happen when people rely too heavily on technology or abdicate too much of their role to machines. Furthermore, people who assume that technology can completely substitute for human interaction can envelop themselves in a false sense of security. 

When personnel use bar-code scanners to process orders, adequate time must be allotted. ISMP advises pharmacists and pharmacy technicians to take only one order at a time from a stack. Consideration should be given to designing a system that requires a confirmatory scan before a drug is dispensed. 

Discrepancies between the MAR and the patient's medication supply should be checked against the original order before drug administration. Furthermore, comorbid conditions such as diabetes mellitus should be noted on the patient's MAR and nursing worksheets. In this case, the nurse administered antidiabetic medications without any confirmation that the patient had diabetes. The patient was not told the purpose of the medications. 

Last, pharmacy personnel should not assume that a discrepancy between pharmacy's and nursing's records can be reconciled simply by having another copy of the order in hand. Not every discrepancy between records is the result of a missing order. By looking through the batch of processed orders for the date and time in question, a pharmacist or technician might have found the order for the antidiabetic medications, investigated the matter, and discovered the error. 


This Medication Errors Alert is provided by the American Society of Health-System Pharmacists and the Institute for Safe Medication Practices (1800 Byberry Road, Suite 810, Huntingdon Valley, PA 19006; 215-947-7797; Practitioners can report medication errors at and discuss errors in confidence at