The dispensing accuracy of ROBOT-Rx
From the August 25, 1999 issue
The dispensing accuracy of ROBOT-Rx from McKesson-HBOC Automated Healthcare is impressive, but the system can still allow errors. This centralized robotic drug distribution system automates dispensing and restocking of bar-coded medications and is highly accurate in providing unit doses for inpatients. However, special bar-coded unit dose packaging is required for every dose picked by the robotic arm. Since bar coding is not commercially available on all medication packages, a significant percentage of doses must be repackaged (e.g., from bulk containers) or overpackaged (e.g., for a non-bar-coded unit dose item) in-house or by contractors, including drug wholesalers, who provide such services. With varying degrees of quality assurance during repackaging, a wrong drug or an incorrect number of tablets can be placed in the bar-coded package. Errors can also happen during the filling process.
Patient drug bins move on a conveyor belt and stop for filling by the robot. Sometimes bins become crowded and overloaded if a patient is receiving multiple medications. As doses drop from the robot arm into the overloaded bin, it’s possible for a package to fall into an adjacent patient’s bin. Errors are also possible when the ROBOT-Rx restocks doses that are returned unadministered. A pharmacy technician takes each returned unit-dose package and places it randomly on a pegboard. The robot removes each dose from the board, reads its bar code, and replaces it into its proper location within the system.
However, sometimes nurses place empty packages back in the patient’s bin. These may go unrecognized by pharmacy personnel who place returned doses on the pegboard for restocking by the robot. Thus, an empty bag may be placed into stock and later dispensed. Also, liquids in the patient’s bin can leak or spill, causing the back of the plastic package to become sticky. Later, during the restocking process, the back of that medication package may stick to the front of a different medication package which is located behind it on the same peg. Thus, during a future dispensing cycle, both packages of drugs are placed into the patient’s bin, one of which has not been ordered.
Despite these possible shortcomings, ROBOT-Rx is being used successfully in many US hospitals where it helps to reduce time-consuming manual tasks and dispense doses with a degree of accuracy that exceeds manual dispensing. Also, with a bar code on each dose, the system is positioned to facilitate future bar code scanning of doses during drug administration.