Radio frequency identification devices for tracking blood products and medical supplies in hospitals demonstrated enough electromagnetic interference with intensive care unit equipment to be potentially hazardous to patients, according to a report in the June 25 issue of JAMA.
The findings are alarming because the application of such radio frequency identification devices (RFIDs) is increasingly being explored in health care settings, Dr. Donald Berwick noted in an accompanying editorial.
The technology, which is used in everything from security access cards to electronic toll-collection devices, is currently under investigation for remotely monitoring medical equipment and for tracking inventory and the placement of specific items such as surgical sponges.
The findings suggest that on-site tests of electromagnetic interference are warranted before hospitals start using new RFIDs, said Dr. Erik Jan van Lieshout, one of the study's coauthors from the University of Amsterdam, and his associates.
The investigators analyzed the effects of two RFIDs on 41 medical equipment systems in simulation studies that did not involve patients. The RFIDs were selected because they were being studied for their usefulness in tracking blood products and expensive medical supplies in the ICU.
Each of the 41 medical equipment systems was subjected to three tests of electromagnetic interference in a one-bed ICU room. Of the 123 tests, 34 induced an electromagnetic interference incident that was reproducible. Of those 32 incidents, 22 were considered potentially hazardous and included the switching off of ventilator equipment, complete stoppage of syringe pumps, and incorrect inhibition of pacemakers (JAMA 2008;299:2884–90).
The RFID that had a passive tag, meaning that it is powered by the electromagnetic field of the reader device, induced a greater number of incidents than did an active tag, in which a power source transmits continuously to the reader. The median distance at which the incidents occurred was 30 cm.
In his editorial, Dr. Berwick took issue with the investigators' disclaimer that their findings apply only to the specific RFID systems they tested.
“Frankly the 2 tested systems are not unlike many others in current use, and attention must be paid to these disturbing findings,” wrote the president and chief executive officer of the Institute for Healthcare Improvement, based in Cambridge, Mass. (JAMA 2008;299:2898–99).
'Attention must be paid to these disturbing findings.' DR. BERWICK