A brief perusal of LITFL has yielded a nice summary of this topic, most relevant to inteference with the function of pacemakers and AICDs.

In briefest summary:

Causes

  • Diathermy
  • Mobile phones (don’t place over pacemaker)
  • MRI
  • Peripheral nerve stimulators
  • TENS machine
  • Defibrillation

Effects

  • Damage to the device
  • Reprogramming of the device (usually they default to asynchronous mode)
  • Induction currents in the leads, resulting in heat damage
  • Interference with monitoring activity
  • Stimulation of autimatic defib functions (embarrassing)

Prevention

  • Use of bipolar diathermy
  • Placement of monopolar diathermy electrode pads to divert current away from the pacemaker
  • Telemetric programmer and cardiac technician in theatre, or on standby
  • Defib pads as far from pacemaker as possible

As far as electromagnetic radiation in the ICU is concerned, there are several points to note.

  • 1990s cell phones were the first to cause observed interference with medical devices
  • The range for interaction was about 2m
  • Early analog devices were to blame; ventilator and neonatal incubator failures were observed
  • Since then, improvement in technology has resulted in digitisation of signal and decreased transmission power requirements, with a resulting decrease in the incidence of RF interference.
  • Additionally, shielding standards for medical equipment have escalated the mandatory level of RF protection.
  • Modern cell phones are unlikely to cause significant interference unless they are in the immediate proximity of an unshielded device.
  • WiFi and Bluetooth are generally held to be benign.
  • Most hospitals have subsequently either suspended their mobile phone bans, or maintained them for the purposes of noise reduction.

References

Van Der Togt, Remko, et al. "Electromagnetic interference from radio frequency identification inducing potentially hazardous incidents in critical care medical equipment." Jama 299.24 (2008): 2884-2890.

Lapinsky, Stephen E., and Anthony C. Easty. "Electromagnetic interference in critical care." Journal of critical care 21.3 (2006): 267-270.

Baba, Isao, et al. "Experimental study of electromagnetic interference from cellular phones with electronic medical equipment." Journal of Clinical Engineering 23.2 (1998): 122-134.