Problems included attaching the wrong infusion pump to a patient, incorrectly calculating the volume of drugs, and “numerous cases” of the pump being clamped shut so the patient absorbed none of the medication. ... The team highlighted three serious flaws: The lack of a second worker in some pharmacies to check whether a chemotherapy solution had been properly combined; work surfaces where several bags of chemicals were being prepared at one time, raising the risk of mix-ups; and failing to keep a label bearing the patient’s name attached to the infusion bag at all times, increasing the chances of giving patients the wrong drugs.
I can't believe that such simple mistakes are that common, so I wanted to see what the original authors said. Unfortunately, the original article (found here) can't be accessed by the general public and you need institutional access to read it, but the actual report makes a valuable conclusion:
Three types of previously locally unrecognized potential chemotherapy preparation errors in Canadian oncology pharmacies have been uncovered in this study, all of which are undetectable if they occur.But falls short of actually publishing a damning result that quantifies the extent of their findings:
Although the frequency of these errors is unknown, their impact is potentially catastrophic.A little disappointing, but it may not be the author's fault: Lukewarm conclusions usually aren't intentional and might reflect something being out of the scope of the study.
Nevertheless, it's too bad no quantification of errors is offered, because knowing how often mistakes in preparing doses of chemotherapeutics would give anyone the measuring stick needed to change policies and fix this problem. A measurement of error would also translates the problem from a medical one (what dosage to provide) to a general management issue (how often does the product meet specifications).
The mistakes described in the Post article are high school level errors that are baffling in the context of the highly trained people who make them, suggesting that either people are either unfit for the job or overworked. If the former, train them, implement a system to check for errors, or move them. If they're overworked, either make the job easier or hire more people.