Cochlear implant

An implanted hearing device with an electrode in the cochlea and a magnet under the scalp. The ED facts: recipients are at higher risk of bacterial meningitis - treat ear infection and meningitis promptly - and diathermy and MRI need precautions.

Adult & paediatricNeurologicalStated practice - no UK guideline found

Also called: cochlear implant, CI, bionic ear, hearing implant, auditory implant, implanted hearing device

What it is

A cochlear implant restores a sense of hearing to profoundly deaf people. An external sound processor behind the ear sends signals across the skin, via a magnet, to an internal implant whose electrode array sits inside the cochlea. It is common in children (born profoundly deaf) and adults.

For the ED, two things matter. First, a cochlear implant raises the risk of bacterial meningitis: the MHRA states People with cochlear implants may have an increased risk of contracting bacterial meningitis, because the electrode entering the cochlea can offer a route for infection to reach the meninges. So these patients should be pneumococcal-immunised (per the Green Book), and ear infection or meningitis symptoms must be taken seriously and treated early. Second, the implant (and its internal magnet) means diathermy and MRI need precautions. It does not otherwise change acute care.

How to recognise it

An external sound processor worn behind the ear, attached to a round transmitter coil held onto the scalp by a magnet; a scar behind the ear and, on imaging, a coiled electrode in the cochlea.
A profoundly deaf patient (often a child) who communicates via the implant and whose family can describe it.
The reason for attendance may be unrelated - but ear pain/discharge, fever, headache, neck stiffness or being systemically unwell in a recipient should raise meningitis and middle-ear infection high on the list.

What goes wrong

Bacterial meningitis (higher risk)

Fever, headache, neck stiffness, photophobia, drowsiness or a septic picture in a cochlear implant recipient - who is at elevated risk.

Red flag
The electrode is a potential route: the presence of stimulation electrodes passing into the cochlea may present a route for the spread of infection which, if left untreated, may lead to bacterial meningitis. Treat suspected meningitis immediately on the standard pathway - do not let the implant delay antibiotics - and involve the implant team.

Middle-ear / device-site infection

Acute otitis media, or redness, swelling, discharge or pain over the implant site.

Red flag
In a recipient, middle-ear infection can track to the meninges, so treat it promptly: Diagnose and treat middle ear infections promptly in implanted recipients using the appropriate antibiotics, and Any suspected infection in your ear or around the device requires immediate medical attention. Involve the implant centre for a device-site infection.

Diathermy / MRI hazard

A recipient going to theatre or being referred for MRI without the implant being flagged.

Red flag
Diathermy near the head and non-approved MRI can damage the implant or injure the patient; MRI can damage your implant so is best avoided if an alternative scan is possible. Flag the implant and follow the MRI/diathermy panel; TMS and ECT should not be used.

The implant is not the acute problem

A recipient with an unrelated acute illness where the focus drifts to the device.

Red flag
Treat the acute illness normally; the implant mainly adds the meningitis vigilance and the diathermy/MRI precautions. (A non-working processor is an audiology, not an emergency, issue.)

The first ten minutes

Treat suspected meningitis in a recipient immediately - standard sepsis/meningitis pathway, blood cultures and antibiotics without waiting; the implant raises the risk and must not delay treatment.
Take ear infection seriously - acute otitis media or a device-site infection in a recipient warrants prompt antibiotics and a low threshold for escalation, given the meningitis route.
Flag the implant before diathermy or MRI - no diathermy near the head, and no MRI until cleared for the specific device (see the panel).
Communicate well - the patient is profoundly deaf; if the external processor is off or removed, use written communication, an interpreter or the family, and let them keep/replace the processor where possible.
Check pneumococcal immunisation status opportunistically and advise per the Green Book.
Involve the cochlear implant team for device-site infection, implant concerns, or MRI/surgery planning.

Do not

Do not let the implant delay treatment of suspected meningitis.

Recipients are at increased risk of bacterial meningitis and it is rapidly fatal. Treat on the standard pathway immediately; the device is a reason for more urgency, not less.

Do not dismiss otitis media or a device-site infection in a recipient.

Middle-ear and device-site infection can track to the meninges. Treat promptly with appropriate antibiotics and involve the implant centre for device-site infection.

Do not use diathermy near the head or send for MRI without clearance.

Diathermy and non-approved MRI can injure the patient and damage the implant. Flag the device and follow the MRI/diathermy precautions; use an alternative scan where possible.

Do not forget the patient cannot hear you with the processor off.

Removing or losing the external processor leaves a profoundly deaf patient; failing to adapt communication risks missed consent, missed symptoms and distress. Use written communication, the family or an interpreter.

Who owns it

The cochlear implant programme / ENT owns the device. For the acute emergency, the general/medical team treats meningitis or infection on the standard pathway. Tell the implant centre about any device-site infection, meningitis, or planned MRI/surgery. Flag the implant to surgery and anaesthetics.

MRI and diathermy with an implanted neuro device

Three implanted neuro devices turn two routine hospital exposures - diathermy and MRI - into potentially lethal ones. The rule is the same for all of them: identify the device from the patient's card, and clear MRI and diathermy with the implanting centre before either happens. Never assume a scan or an operation is safe because the patient 'has had one before'.

Diathermy can kill - deep brain stimulation above all: The device label bars shortwave, microwave and therapeutic-ultrasound diathermy - anywhere on the body, with the system on or off. For DBS the manufacturer is explicit: Energy from diathermy can be transferred through the implanted system and can cause tissue damage at the location of the implanted electrodes, resulting in severe injury or death. Theatre electrosurgery (surgical monopolar diathermy) carries the same risk and must also be flagged - to every surgeon, anaesthetist and physiotherapist.
MRI is conditional, never assumed: MRI is not a simple yes/no - it depends on the device model, the coil and the scan. For DBS a contraindicated scan is lethal: Tissue lesions from component heating, especially at the lead electrodes, resulting in serious and permanent injury including coma, paralysis, or death, can occur if a contraindicated MRI scan is performed. For a cochlear implant, MRI can damage your implant so is best avoided if an alternative scan is possible. Clear every scan with the implanting centre first.
Cochlear implant: diathermy and other energy: Monopolar diathermy can be used below the neck as long as care is taken to ensure that current does not pass near the head: it is safer to use bipolar diathermy where possible. And Procedures such as transcranial magnetic stimulation (TMS), electro-convulsive therapy (ECT) and neurostimulation, should not be undertaken.
Programmable shunt valves and stray magnets: Many CSF shunt valves are programmable - the closing pressure to be altered externally using a special magnetic device - so a stray magnet can change the setting, and it can lead to problems following an inadvertent change of pressure. MRI is a recognised cause of inadvertent reprogramming (per the valve manufacturers' labelling), so after any MRI a programmable valve must be checked and reset by neurosurgery.
What to do: Get the device identification card and the model; flag the implant to everyone planning diathermy, MRI, TMS or ECT; and contact the implanting centre before proceeding. When in doubt, choose an alternative to MRI (e.g. CT) and avoid diathermy entirely.

Who to call

The team and the criteria are national. The phone number is local, and this tool does not know it. Find it once, now, and write it on the department's own card — that is the part no website can do for you.

Say the device name first: Open with laryngectomy, LVAD, shunt — the single word changes who comes and what they bring. Do not bury it in the history.
Say what you have already established: Whether the device is patent, whether it has been removed or disturbed, and what you have already tried. The specialist is deciding whether to walk or run.
Ask who owns it out of hours: Device ownership and the on-call route often differ from the implanting specialty, and it is frequently a regional centre rather than your own hospital.
The patient's own team is a resource, not an afterthought: Named nurse specialists, home-care companies and device helplines answer questions nobody else can, and the patient usually has the number.

When the device is not the problem

A patient with a device gets pneumonia, sepsis, pulmonary oedema and myocardial infarction at the same rate as everybody else. The device is the most visible thing about them and it attracts the whole assessment.

The NTSP says it out loud: The project's own manual warns that patients with tracheostomies can become unwell with all the problems that other patients get too. It is easy to become fixated with the tracheostomy. The same sentence applies to every device in this tool.
Clear the device, then leave it: Establish that the device is doing its job — the stoma is patent, the line draws back, the pump is running — and then assess the patient as you would anyone else.
The anchoring runs both ways: The opposite error is treating a device complication as a medical illness: a blocked gastrostomy read as vomiting, a baclofen pump failure read as sepsis.

NTSP manual — Red flags · read in full

What the patient will be carrying

Recipients carry an implant identification card with the manufacturer and model (needed for MRI decisions) and know their implant centre; children's families are expert in the device and communication.

Scope of this page

This page covers the ED-relevant issues with a cochlear implant: the raised meningitis risk and prompt treatment of ear infection, the diathermy/MRI precautions, and communicating with a profoundly deaf patient. It does not cover implant mapping, processor faults or audiological troubleshooting (the implant centre's role). Cochlear implants are used in adults and children; the device-specific MRI rules depend on the manufacturer and model.