Patient controlled analgesia by proxy

The Joint Commission's Sentinel Event database contains only one medication error related to PCA by proxy. However, reports submitted to the U.S. Pharmacopeia (USP) medication errors databases* revealed a combined total of 6,069 PCA errors. Of this number, 460 resulted in fatality or some level of harm to the patient—impairment of the physical, emotional, psychological function or structure of the body and/or pain resulting therefrom. Fifteen of the 460 cases were the direct result of PCA error by proxy—12 cases attributed to family members, two to a nurse and one to a pharmacist. Five of the 460 errors were fatal errors, including one "by proxy" error attributed to a nurse. While the setting or location of the error was not identified in all cases, 401 of the 460 cases occurred within the hospital with the majority of errors experienced in the patient care units. Other sites within the hospital included the post-anesthesia care unit, inpatient pharmacy, intensive care unit (surgical, medical, coronary/adult, pediatric and neonatal), oncology department, pediatric unit, maternity and labor and delivery unit, the operating room, outpatient surgery unit, endoscopy/GI lab, and pre-operative holding area.

Over the past several years, the Institute for Safe Medication Practices (ISMP) has issued a number of warnings and reports alerting health care organizations and practitioners to safety issues related to PCA by proxy. "With PCA, the patient provides a measure of safety because the analgesia is delivered at doses lower than what is needed for sedation and an oversedated patient will not push the PCA button to give additional opiate," explains Michael Cohen, R.Ph., M.S., Sc.D., president, ISMP. "Bypassing this built-in safety feature is potentially dangerous." 

Root Causes Identified
"PCA by proxy errors are usually the direct result of family members and/or health care professionals administering doses for the patient, by proxy, hoping to keep them comfortable," says Cohen. "This well-intentioned effort can result in oversedation, respiratory depression, and even death. Patients, staff and family members must be warned about this potentially dangerous aspect of PCA.

"While nurse-controlled analgesia using a PCA infusion device may be used in some settings and offers advantages, protocols and appropriate assessment tools must be in place to gauge the level of pain, sedation and respiratory status," Cohen says. Contributing factors in PCA by proxy errors involving health care professionals may include improper patient selection, inadequate patient monitoring, and insufficient training or education related to the selection of drugs, dosing, lockout periods and infusion devices.

Joint Commission recommendations
PCA by proxy errors are highly preventable and can be significantly reduced with adequate and appropriate education and training of staff and family members. To reduce the risk of PCA by proxy overdose, the Joint Commission—on the advice of ISMP and USP—offers the following safe practice recommendations:

1)   Develop criteria for selecting appropriate patients to receive PCA and nurse-controlled analgesia. This criteria-based selection process should consider the risk that PCA by proxy might occur. Some patients may not be appropriate candidates to receive PCA because of their age (infants and young children are not appropriate candidates); their mental state (confusion, agitation, restlessness); or due to their level of consciousness, psychological stability, or intellectual capacity. When assessing a patient for nurse-controlled analgesia, identify risk factors such as age, weight, pre-existing conditions including allergies, and current medication use that may suggest increased monitoring.

2)   Carefully monitor patients. Even at therapeutic doses, opiates can suppress respiration, heart rate and blood pressure, so the need for monitoring and observation is critical. Oximetry and/or capnography monitoring may be appropriate in some cases.⁴

3)   Teach patients and family members about the proper use of PCA and the dangers of others pressing the button for the patient. Provide written instructions to family members that instruct them NOT to administer PCA doses.

4)   Alert staff to the dangers of administering a dose for the patient outside of a nurse controlled analgesia protocol.

5)   Consider placing warning tags on all PCA delivery pendants that state, "Only the patient should press this button." Alternatively, consider posting warning signs in all areas where PCA therapy is used that state, "Only the patient should press the PCA delivery pendant."

References

¹ ISMP Medication Safety Alert! May 29, 2002, Institute for Safe Medication Practices
² ISMP Medication Safety Alert! July 10, 2003, Institute for Safe Medication Practices
³ ISMP Medication Safety Alert! July 24, 2003, Institute for Safe Medication Practices
⁴ Maddox, R.R.; Williams, C.K.; Fields, M. "Respiratory monitoring in patient-controlled analgesia," AM J Health-Sys Pharm 2004;2628-9