Hello Raymond,

Thank you for your question regarding cochlear implants.

Contacting the manufacturer of the cochlear implant and consulting
with the surgeon who placed it is the best first step in determining safety.  Many device manufacturers have tested their
product in a hyperbaric environment and/or are familiar with safety questions
regarding HBOT.  Pressure changes during
hyperbaric therapy potentially can cause damage to the implant.  Cochlear implants also have a battery which
is a source of heat.  Some have an
external processor section which houses the battery and may be disconnected and
removed.  Even if the battery can be
removed, determination needs to be made regarding safety and risk of the
internal component’s ability to function and risk of damage under
pressure. 

Resources:

• Go No Go Tool
• In WoundReference, the Introduction to Hyperbaric Oxygen Therapy topic, lists cochlear implants as a relative risk due to malfunction of
  internal components secondary to pressure change.

Upon reviewing this information, the final determination of whether an item or device is permitted in a hyperbaric chamber is made and agreed upon by the Medical Director and Safety Director of a hyperbaric program.

Hope this helps!

Dr. Jacques,

Thank you for your question. Lessons learned from previous mishaps have improved guidelines for safe chamber operations. The hyperbaric facility is safe–provided a qualified team with a safety-conscious attitude who adheres to established safety practices and operates it. As is recommended with any implanted device, verification by the manufacturer of testing and function in hyperbaric environments is necessary before initiating treatment.

For those without experience with cochlear implants, the cochlear implant is surgically placed under the skin behind the ear. The essential parts of the device include Internal and External components.

The External Components:

•  One or more microphones, a speech processor, and a transmitter, a coil held in position by a magnet placed behind the external ear and transmits power and the processed sound signals across the skin to the internal device by electromagnetic induction.

The Internal Components:

•  A receiver and stimulator secured in bone beneath the skin converts the signals into electric impulses and send them to electrodes through an internal cable.

•  Electrodes pass through the cochlea, which sends the impulses to the nerves to the brain through the auditory nerve system.

The fundamental question(s) with any implanted device - Is there a fire risk or damage to the device in a hyperbaric environment?

Considerations with documentation (written) from the manufacturer confirming safety testing for use in a hyperbaric chamber for Cochlear implanted devices: the hyperbaric team should take the following precautions.

1.     Deactivation of the CI prior to each treatment by removal of the external component. The deactivation will likely result in barriers to communication.

2.     The hyperbaric physician must weigh the risks and benefits of treating patients with a CI that has been deactivated for treatment.

3.     Documentation verifying product testing in a hyperbaric environment must be obtained from the manufacturer prior to treatment.

4.     The documentation must identify the specific testing pressure (e.g. 2.5 ATA)

5.     The patient should consult their audiologist or ENT to verify the proper functioning of the device prior to the initiation of HBOT and upon completion of the therapy course.

A similar question was submitted to the UHMS Safety Committee; the corresponding response was posted on the UHMS website on January 10th, 2018. The response was as follows.

The UHMS hyperbaric oxygen safety committee (SC) can provide information, but the ultimate responsibility for answering these types of questions is with the medical director and safety director of your facility. As with many medical devices considered for exposure to hyperbaric conditions, the Safety Committee recommends consultation with the device manufacturer and proceeding with caution.

The UHMS Safety Committee is aware of several hyperbaric centers that would remove the external portion of the device, leaving the titanium implant in place. This is a reasonable approach, as changes in atmospheric pressure could damage the external device. Furthermore, the energy generated by the battery is a heat source that could cause harm to a patient receiving hyperbaric oxygen therapy.¹

Additional considerations should be given to the ability to communicate with the patient during therapy. Furthermore, we advise that any medical concerns derived from the removal of this device be brought to the attention of the patient’s otolaryngologist.¹

Again thank you for your question.  Have a great day!  Jeff

References

1.     UHMS Medfaq, UHMS.org;  https://uhms.org/resources/featured-resources/medfaqs-frequently-asked-questions-faq/search/0.html?yrfaqsearch=cochlear

2.     J Oral Maxillofac Surg. 1999 May;57(5):493-9. “Osseointegrated implants in irradiated bone: a case-controlled study using adjunctive hyperbaric oxygen therapy.”

3.     Backus D. et.al., Effects of Hyperbaric Exposure on the Integrity if the Internal Components of Commercially Available Cochlear Implant Systems, Otology&Neurotology (2002) 23:461-467

4.     Hyperbaric Oxygen TreatmentHyperbaric Oxygen TreatmentCategory: Mechanical Impact; Pressure