Brain stem evoked response test under sedation

What is sedation?

We have arranged for your child to have sedation for a hearing test. Sedation is a when we make someone less aware of their surroundings. For this test we have found a nasal spray to be particularly effective. The drug used, dexmedetomidine, mimics natural sleep. After the dose is given, the majority of children fall asleep within thirty minutes and can be sedated for up to two hours. Once the effects have worn off your child can eat and drink and can usually be discharged home.

Are there any side effects?

The main side effect is drowsiness. We will be monitoring your child during and after the procedure. Serious risks are rare with this technique and our staff will be happy to discuss any concerns or questions you may have.

What is a brain stem evoked response (BSER) test?

This is a way of checking hearing that can be used on anybody from newborns to adults.

Babies and young children need to be asleep for the test, older children must lie very still, or the test will not work. Some children will need sedation to help them lie still.

What exactly does it involve?

Sticky pads (electrodes) are placed on the head, 1 behind each ear and 2 on the forehead. These are then connected to the BSER equipment and a headphone is placed over each ear in turn so that sounds, some loud and some quiet can be played.  Any response is recorded on the screen as a waveform.

The audiologist will explain in further detail at the appointment.

Does it hurt?

No. In order for the electrodes to be attached, your child’s skin needs to be prepared. The skin is rubbed with an exfoliating scrub which may feel a little uncomfortable however this will remove any surface oils and dead skin cells which will help obtain a clearer response. Your child may be asleep before we start this process.

How long will the test take?

The test may take around 1 hour but you will be at the hospital for around 3 to 4 hours.

Will I know the results straight away?

Yes. We can usually tell you the results if they are clear. Sometimes the waveforms on the screen are not very clear and this is often because the background noise levels are too high. In a very small number of cases we are not able get any definite results from this test.

All the traces are reviewed by a second audiologist after the test is completed. If any changes are made to the results, you will be notified of these.

What happens if a hearing loss is detected from this test?

The next step would be to try to find out what is the cause of the hearing loss.

It could be a temporary problem which is likely to be caused by the presence of fluid in the middle ear, this is known as a conductive hearing loss. In these cases, we would recheck the hearing in a few months. We might ask for an opinion from an Ear, Nose and Throat consultant.

If the results suggest a more permanent hearing problem, involving the inner ear or the hearing nerve, this is known as a sensorineural hearing loss. We would then ask you to attend an appointment with a specialist doctor in Medical Audiology within the Hearing Services department.

If my child is found to have ‘normal’ hearing, will they need any further hearing checks?

The audiologist will discuss with you the best course of management for your child.