Do Cellular Devices and 2-Way Radios Affect Ventilator Function?

Abstract & Commentary

By David J. Pierson, MD, Editor, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, is Editor for Critical Care Alert.

Synopsis: Cellular telephones from 2 telecommunications systems and the 2-way radio used by local emergency services affected some of the ventilators tested (the older models), but only at close proximity, and no device tested had any effect on any ventilator beyond a distance of 1 meter.

Source: Dang BP, et al. J Crit Care. 2007;22:137-141.

In this study, investigators at the University of Saskatchewan sought to determine whether current-technology cell phones and 2-way radios affected the function of the ventilator models in use in their province. The ventilators used were the Maquet Servo 300, the Puritan-Bennett 7200, the Draeger Babylog 8000, the Bird VIP GOLD Pediatric, the Pulmonetics LTV 1000 transport ventilator, the CPAP Sullivan III, and the Respironics BiPAP Synchrony. The mobile communication devices tested were cell phones from the 2 telecommunications systems serving Saskatchewan and the MRK/810-815 mHz/3w Ericsson GE walkie-talkie, which operated on the local system at a fixed power output of 3.0 w when in use.

Dang et al enlisted the technical assistance of the local provincial phone company, which provided the 2-way radio and one of the cell phones and helped to standardize and validate the testing procedures. The ventilators were placed in operation using a test lung in a basement room in the hospital. The cell phones and radio were tested under circumstances in which maximum power was used and the most interference with ventilator operation could be expected. They were placed at 0 m, 0.5 m, and 1.0 m, and farther from each ventilator if closer distances were associated with detectable changes in ventilator function.

The 2-way radio caused significant interference with the Puritan-Bennett 7200 at all distances up to 1.0 m, and with the pulmonetics LTV 1000, the Draeger Babylog 8000, and the Bird VIP GOLD at 0 m. The radio also caused the BiPAP Synchrony to shut down when placed at 0 m from the machine. The Motorola V300 cell phone, serviced by the more powerful of the 2 systems, caused interference with the Puritan-Bennett 7200 at 0 m only. None of the devices affected the Servo 300 or the CPAP Sullivan III, the 2 newest machines tested.

The authors point out that, with current technology, it is not the individual cell phone (of which there are a bewildering variety today) or the service provider (of which there are numerous, varying by region) that is relevant to potential influence with ICU devices, but rather the telecommunications system. The different systems vary, and it is the system to which a device is connected that determines its power output.

The authors conclude that interference from mobile communications devices is less of a problem with newer ventilators than with older models, and that even with the older, more vulnerable machines, such devices are safe to use if they are not operated within 1 m of the ventilator.

Commentary

Personal cellular devices and 2-way communications systems have become indispensable to health care professionals and are ubiquitous today. Despite their usefulness and their penetration into many aspects of hospital and ICU operation, such devices have the potential to interfere with ventilators and their vital electronic equipment. Because life support is involved, the stakes are high, and as a result the use of cell phones and other mobile communication devices has been banned in many ICUs. However, as this article illustrates, this area is evolving rapidly and the issue might need to be revisited. Given the value of the devices and the advances in recent equipment design, it may not be desirable to keep mobile communication units out of the ICU.

Dang et al point out that their study was targeted at the ventilators and communication systems in use in Saskatchewan, and that caution should be used in generalizing their findings beyond this context. It would seem advisable for individual hospitals to find out about their local telecommunication systems and the characteristics of the ventilators in use in their ICUs and elsewhere in their institutions. In any event, it is reassuring to note that the likelihood of interference with ventilator operation seems low if cell phones and other devices are kept at least 1 m away.