November 30, 2011

How often do errors with patient-controlled analgesia occur? More often than we know, research suggests.

Researchers who studied more than 900,000 medication record errors say that the 1% of errors related to patient-controlled analgesia (PCA) is probably just the tip of the iceberg. Although 1% may seem insignificant, this analysis was based on the voluntary medication error reporting, says lead researcher Rodney Hicks, Ph.D., who at that time of the study was manager, patient safety research and practice, U.S. Pharmacopeia.

By Michael Wong

"Although generalization of voluntary reported findings to the general population should be done cautiously," he points out, that "the general rule of thumb is that for every reported event, there can be between 300-1,000 unreported events."

This rule of thumb, based on 9,571 reported events, would mean that between 2.8 million and 9.6 million total events (unreported & reported) occurred over the 5-year period from July 1, 2000, to June 30, 2005. On an annualized basis, this would mean that about 600,000-2 million events/year could involve PCA.

These numbers are unacceptable in what should be an era of increasing patient safety. Says Dr. Hicks, "Further study would need to be done to ascertain the total number of PCA events, but the problem is extensive in my opinion." The picture is already pretty clear, but there is more to the data.

When the study looked at the number of events that caused harm, there were 624 records of PCA associated with harm, corresponding to 6.5% of the patients. Again, while 6.5% may seem small, as the study found, "By comparison, during the same period, only 1.5% of all other errors reported to MedMarx led to harm. This represents a fourfold higher relative risk of harm for PCA events."

"All health care disciplines were implicated in the errors, including physicians, pharmacists, and nurses" he said. "Therefore, it will take an interdisciplinary team to resolve the problems."

Dr. Rodney Hicks

Dr. Hicks’ retrospective study of the magnitude, frequency, and nature of nonharmful and harmful medication errors associated with patient-controlled analgesia covered a 5-year review period with 919,241 medication errors records from 801 reporting health care facilities. The analysis was based on the international voluntary medication error reporting program, MedMarx. Dr. Hicks is now a professor a Western University College of Graduate Nursing, Pomona, Calif.

"Our analysis was in no means trying to discourage the use of PCA pumps. Many studies have shown the benefits of using PCA, including improved pain management, better utilization of nursing resources, increased patient satisfaction, and improved pulmonary function.

"However, this is clearly an indication that standardization needs to occur and organizations should invest in training and policies and procedures as well as equipment – all areas to promote safety."

Moreover, although elimination of error is critical, studies have shown even a correctly programmed PCA pump poses patient safety risks.

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