Automated systems cut medication error risk

Study focuses on cabinet system access

With the push for a systemwide approach to decreasing medication errors, the role of automated distribution cabinets increasingly is being tested. A recent observational study undertaken at a 700-bed tertiary care referral hospital in the Mid west focused solely on the access phase of drug distribution — the actual removal of drugs from the cabinet, The research ers found 13 errors out of 188 transactions for an error rate of 6.9%.

Clinical pharmacists overseeing the study established "incorrect drug, incorrect dose, incorrect dosage form, incorrect frequency, incorrect patient, and access without an active physician’s order" as the error categories, as well as error comparison categories based on drawer types and errors occurring in general vs. intensive care units.

Analyzing a Pyxis Medstation offering both single-access (one medication, multiple doses) and multiple-access (different drugs, multiple doses) drawers, researchers found no basic difference in access error rates. Likewise, they found no significant differences between the use of cabinets in the general or intensive care units. In both settings, the hospital’s cabinets were used for controlled substances, basic floor stock, intravenous solutions, and sets.

To ensure the resulting data were sound, staff checked cabinet inventories for proper stocking and restocking prior to each hospital shift. They followed up with inventories every two to four hours to guard against crossover discrepancies in cases where, for example, inventory counts may be accurate even though two patients received drugs meant for each other. Study data included patient names, ID, and room numbers; transaction dates and times; the ordered and removed drug; and whether access was from single or multiple drawers or done within general or intensive care units.

The 13 errors found included nine cases (69.2%) based on access without an active physician’s order, two cases (15.4%) of incorrect frequencies, one incorrect dose (7.7%), and one incorrect dosage form (7.7%). No errors involved accessing drugs for the wrong patient or at the wrong dose.

After reviewing the results, the study’s authors found that drug access without a doctor’s order, by far the largest breakdown in the cabinet system, was largely based on the removal of a controlled substance beyond the automatic stop-order date.

As a solution to this type of problem, the authors note that "upgraded software that creates a link to the hospital pharmacy computer system is available for use with many automated storage and distribution cabinets. This link ensures access to a medication for a particular patient only if a physician’s order for the medication is processed by the pharmacy and entered into the system. Our results suggest that this kind of linkage software may be an important component of an automated storage and distribution system and could have a substantial impact on access discrepancies."

The authors argue that besides software, everything from the physical layout of a cabinet system, the use of a mousepad, touchscreen, or keyboard, and the use of single- or multiple-access drawers can make a difference.

Most important, however, is how an institution handles what the authors call formulary convention: whether medications are listed by brand or generic names, whether cross-referencing is used, how drug names are put into the system and then accessed, and whether similar drugs are stored in different drawers. Researchers praised hospital officials for separating drugs with similar-sounding names and those that simply look alike.

For more details or a reprint of the study, contact: David Mott, PhD, Assistant Professor of Social and Administrative Pharmacy, University of Wisconsin School of Pharmacy, 425 N. Charter St., Madison WI 53706. Telephone: (608) 262-1416.