New research suggests that the magnetic drapes commonly used by surgeons during an operation may interfere with cardiac devices, and offers a new shielded prototype solution.
A new shielded prototype developed by researchers at Maisonneuve-Rosemont Hospital in Canada could replace traditional magnetic drapes used in operating rooms. Considered a surgical convenience, magnetic drapes are intended to help physicians manage their metal instruments during surgery; however, new research suggests that the magnets within the drapes may interfere with pacemakers and defibrillators.
“There’s the potential for very significant events during surgery,” Dr. Louis-Pillippe Fortier, head of anesthesiology at Maisonneuve-Rosement Hospital, which is affiliated with the University of Montreal in Canada, said.
According to Fortier, the research team found that commercial magnetic drapes affected pacemakers in 17 out of 27—about two-thirds—of patients tested in a small blind trial. Researchers determined that interference was occurring by monitoring how often the pacemakers entered into magnet mode when exposed to the magnetic drapes.
A wide range of frequency was observed between the four commercially available magnetic drapes tested, with one unnamed brand affecting 18 of 20 patients tested and another affecting just one of 20 patients tested.
The study identified four issues with pacemakers in close proximity to the magnetized drapes: battery depletion; rapid pacing in patients with coronary disease; R on T stimulation (ventricular fibrillation caused by stimulation during the repolarization phase of the cardiac cycle); and arrhythmia detection and treatment suspension for implanted defibrillators.
None of the patients experienced pacemaker issues with the shielded drape prototypes developed for the project. The idea for the shielded drapes came in 2008, says Fortier, when he noticed a change in the electrical activity of a patient’s heart that he attributed to a magnetized drape being placed on a patient’s thorax during a routine laparoscopic cholecystectomy.
Fortier told Anesthesiology News that magnetic drapes are common in his personal experience, but that their widespread popularity remains unclear. Lead author Jeff Healey, MD, a cardiac specialist at McMaster University in Hamilton, Ontario, Canada who was not involved in the study, said that he had not heard about magnetic drapes until recently.
The group presented its findings at the 2013 annual meeting for the Society for Technology in Anesthesia and is in the process of finalizing study results for publication. The new shielded drape prototypes are currently in production.
