Friday, August 12, 2011

The Challenges of Medical Device Follow-up

With the explosion of medical devices to treat various medical ailments in medicine, we have seen significant improvements in quality and quantity of life. An underappreciated consequence of all of these electronic device therapies, however, has been the manpower and expertise required to manage these implanted electronic medical devices long-term.

Problems with electromagnetic interference (EMI) with medical devices are real. Innovations in medicine have come from various portions of the electromagnetic spectrum including analog and digital wireless technology, diagnostic and therapeutic radiation therapy and magnetic resonance imaging. The effects of these technologies on implanted electronic medical devices can vary and specialty physicians, ancillary health care providers, and medical device manufacturers expend significant man-hours managing these potential interference sources and their affects on devices without a single prospective randomized trial to guide us. The sheer number of devices and the many ways that EMI can interfere with these complex devices makes constructing an all-inclusive trial with sufficient number of "events" to compare difficult or nearly impossible. As a result, most of our management recommendations and hospital policies in this regard have been based from literature case reports or personal experience and expertise.

To date, recommendations for minimizing EMI with cardiac implantable electronic devices has been sorely lacking, so the new recommendations published (1.3 Meg pdf) recently by the Heart Rhythm Society (HRS) in conjunction with American Society of Anesthesiologists (ASA) should serve as a helpful guide for physicians involved in the management of these devices. It would be well beyond the scope of this blog to include all of the pre-procedural, intra-procedural and post-procedural recommendations made by this document. But there are some other limitations to these recommendations that warrant mention.

First, there are a multitude of makes and models of pacemaker and implantable cardiac defibrillator devices which are covered by this document. The document is fairly inclusive regarding today's technology. New models forthcoming, however, are not specifically covered by this document (how can they be?) so the challenges keeping these recommendations current will remain a challenge.

Secondly, these recommendations do not cover the management of devices during magnetic resonance imaging, an evolving innovation in these devices, but no less important for patient management in these procedures.

Third, this document covers only implantable electronic cardiac devices. Nerve stimulators, brain stimulators, insulin pumps and a whole host of other implanted electronic devices still remain outside the purview of these recommendations, yet pose similar challenges to patient management, both from a technical expertise AND manpower-need standpoint. The challenges of not only electromagnetic interference, but also device-device interference remain and still need to be considered clinically.

Finally, the recommendations were made in conjunction with the expertise of industry and physician experts. While these recommendations appear to have been made for patients benefit, the real need for the medical device industry to limit their manpower needs for peri-procedural device checks should not go unnoticed. Much of the newer innovations of home monitoring has been forwarded in part to address these simultaneous patient and industry needs. Still, it goes without saying that doctors should remember that any local hospital recommendations developed on the basis of these guidelines should always put the needs of the patient before those of the medical device industry or hospital administration.


Reference: The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and Patient Management.

1 comment:

Anonymous said...

Good summary, Wes. But this document, in addition, is so complex that in no way can it be utilized as a pocket guide in the OR for anesthesiologists or in the office for docs. In addition, I agree that it is in part to minimize company reps involvement. However, when reps are involved, less accidental turn offs and absence of deactivating devices is seen. I have witnessed this firsthand when patients's devices were deactivated by people at referring institutions and never turned back on. Remote monitoring safety alerts potentially saved these people's lives.