Your child is having an MRI or CT scan under sedation

This page contains information about having imaging scans, such as MRI or CT scans under sedation, how to prepare for it and what care your child will need afterwards.

Meet the Team

The Sedation Team is a small friendly group of:

● Advanced Clinical Practitioners

● Clinical Nurse Specialists

● Nurses

● Operating Department Practitioners

● Assistant Practitioners

We also work as part of the wider multidisciplinary team of:

● Anaesthetists

● Radiographers

● Radiologists

● Physicists

● Play specialists

Contact information

If you have any questions or concerns regarding your child’s appointment under sedation, please contact:

Sedation team:

Phone number: 020 7405 9200 ext. 1782, 5909, 5660.

Radiology Play Specialist:

Phone number: 020 7405 9200 ext. 0301

Opening times: Monday to Friday, 7am to 5pm.

The need for sedation during a scan

Some children find it difficult to lie still for their scan, either because of their age or their medical condition. We will always ask if you feel your child can lay still for the length of scan before booking their appointment. We will always advise to try the scan awake first, if possible, to avoid the need for sedation or general anaesthetic due to the associated side effects, which will be discussed at length with you on the day. Therefore, if you feel your child can lay still (they can watch a DVD on the scanner with headphones on for entertainment), then please contact the department on EXT 1782 as soon as possible and we will change the appointment. Your appointment letter will state whether your child is having sedation so you can follow the instructions below to prepare them.

Alternatives to sedation

If your child is unable to lay still for their scan, then the alternative to sedation is a general anaesthetic. Although both options are considered safe, sedation is the preferred method due to it being less invasive, meaning it is a more ‘natural sleep’ whereby your child is breathing unassisted. However, for some children a general anaesthetic is safer due to their weight or condition, a thorough telephone assessment is carried out with the parent/carer of the child by a member of the Sedation Team to discuss this before the appointment is made.

Prior to the appointment

The day before your child’s appointment, you will receive a call from the nursing team to advise you on where to go, the appointment time (it will always be an early morning appointment), and what time your child should eat and drink up until before their appointment. Please ensure you adhere to the fasting times given as your child being fasted incorrectly can lead to cancellation for your child’s safety.

What to bring

You will need to know your child’s full medical history from birth to the present day, including any operations they have had and will need to sign a metal check form stating that it is safe for your child to enter the MRI scanner.

If this information is not known we may have to cancel the scan.

Cancelling your appointment

If you are unable to keep this appointment, please inform the department on 0207 405 9200 ext. 1782 as soon as possible beforehand so we can offer the appointment to another child on the waiting list. As so many children and young people need to use our services, we have had to introduce a policy where if a child cancels or does not attend two appointments in a row, we will close their referral and inform their GOSH consultant.

If your child becomes unwell

If your child becomes unwell within two weeks leading up to the appointment, for example any cough and cold symptoms or unusual vomiting episodes, please contact the Sedation Team on ext. 1782 to inform us of their symptoms so we can establish if they are currently well enough for sedation.

It is important to let us know to avoid any last-minute cancellations as sedating a child when they are unwell can lead to complications under sedation, therefore we would need to reschedule this appointment.

If the sedation practitioner assesses your child as unfit for sedation on the day, then they will cancel the appointment until the child is well enough, we understand this can be frustrating however your child’s safety is paramount.

Preparation for the appointment

On the day of the scan, wake your child at least one hour earlier than usual and try to keep them awake on the way to GOSH, this is because sedation is more effective when your child is more naturally tired.

It is important that your child does not eat or drink anything for a few hours before the sedation. This is called ‘fasting’ or ‘nil by mouth’. Fasting reduces the risk of stomach contents entering the lungs during and after the procedure. It is equally important that your child does not fast for longer than needed as this can cause complications such as dehydration and low sugar levels. You will be given a time that your child can eat up until (this can be anything, even chocolate at 4am) and a time they can drink clear fluids until. Clear fluids are defined as water or diluted squash only.
This does not include, fresh juice, hot drinks, fizzy drinks or milk.

The day before your child’s appointment, you will receive a call from the nursing team to advise you on where to go, the appointment time (it will always be an early morning appointment), and what time your child should eat and drink up until before their appointment. Please ensure you adhere to the fasting times given as your child being fasted incorrectly can lead to cancellation for your child’s safety.

Please bring any comforters, favourite toys and spare clothes to the appointment. Food and drink will be provided in recovery, however please bring any favourite food/drink or any specialist feeds if required.

Play team and distraction techniques

Watch a short video about having an MRI scan and how we can help to distract and play during your visit.

Distraction | Great Ormond Street Hospital (

If you would like further advice about preparing your child for the scan, please contact the department’s play specialist.

Regular medications

If your child is on regular medications, please ensure you give them their morning dose with their last drink. This will be discussed with you further during your call the day before your appointment. If your child is prescribed any emergency medications or equipment such as a tracheostomy box, epilepsy medication or hydrocortisone this must be brought with your child to the appointment.

The appointment

When you arrive at the hospital, you should report to the MRI department on level one (basement) of the Variety Club Building at GOSH.

There are two MRI departments so please listen carefully to the information given to you over the phone the day before your child’s appointment. Details of how to get to GOSH are enclosed with your appointment letter. When you arrive at GOSH, ask one of our volunteer guides to show you the lift or stairs down to the MRI departments.

It is important to be on time for your appointment as we require plenty of time before the scan to safely prepare you and your child for sedation. If you are running late, please inform the Sedation Team on EXT 5660, if you are more than 30 minutes late to your appointment, this may mean your child’s appointment is cancelled.

Your child should wear clothes without zips or metal poppers for the scan – otherwise they will need to change into a gown.

On arrival to the MRI department, you will be greeted by a member of the Sedation Team, they will obtain your child’s height and weight, take observations (such as heart rate and blood pressure), a physical assessment (such as listening to their chest) and taking consent for the sedation.

Only one parent or carer is able to stay at the bedside with the child for safety of overcrowding, however you are able to swap if you wish throughout the day.

It is important that the person with parental responsibility accompanies the child to their appointment for the consent process. If your daughter is 12 years old or older, we will ask her about her periods and we will require to obtain a pregnancy test prior to sedation, as per Local Policy (2018).

The sedation process and medications

Your child may need a cannula (thin plastic tube) for the sedation or for the scan so the nurses will insert a cannula into a vein in your child’s arm, hand or foot - they will use local anaesthetic cream or cold spray to make their skin numb first. Depending on the sedation medication that your child is suitable for (based on medical condition and weight), they may have the sedation given orally (into the mouth), intranasally (into their nose) or intravenously (into the vein), this will be discussed with you by the Sedation Practitioner on the day of your child’s appointment.

Once your child is sedated you can stay with them until the Sedation Team transfer them through to the scan room. You will not be able to go into the scan with them, however one of the Sedation Team will be monitoring them one to one throughout so please take this time to get yourself something to eat and drink. You can go into the recovery area as soon as your child’s scan is finished.

You should be prepared to stay in the department until your child is fully awake and has had something to eat and drink. Most families are able to go home a couple of hours or so after the scan.

Sedative medications

Your child will have one or more of these sedative medicines:

  • Chloral Hydrate – Belongs to the group of medications known as sedatives and hypnotics. It promotes sedation and sleep by acting on certain areas of the brain. It is given orally. Possible side effects include: slow breathing rate, vomiting, irritability and prolonged sleepiness.
  • Midazolam – Works by slowing activity in the brain to allow relaxation and decreased consciousness. This is given buccally (into the side of their mouth and absorbed into their cheek) when intranasal sedation has not been effective after 30 to 45 minutes. Possible side effects include slow breathing rate, irritability and prolonged sleepiness.
  • Dexmedetomidine – Is notable for its ability to provide sedation without risk of respiratory depression and can provide cooperative or semi-arousable sedation. This is given intravenous or intranasal route. Possible side effects include irritability, prolonged sleepiness, low heart rate and low blood pressure.

Risks of sedation

Risks of sedation are rare, and these will be discussed fully on the day before you sign the consent form. Your child will be monitored carefully throughout the sedation and a qualified member of the Sedation Team will be with your child throughout their admission.

Your child may feel a bit wobbly and unsteady on their legs afterwards so please bring a pushchair or buggy with you for the journey home if needed.

The Sedation Team are very experienced and are trained to deal with any complications.

Recovery and discharge

When your child has recovered fully from the sedation and has had something to eat and drink, you will be able to go home. The radiologist (doctor specialising in scans) will send a report of the scan to your child’s doctor in time for their next appointment. If you have not been given a follow up appointment to see your consultant, please contact their secretary after two weeks.

When you get home

Children are generally sleepier than usual for 24 hours after a scan with sedation. This is because the effects of the sedative last for about a day.

If your child is unduly sleepy or difficult to rouse, make sure they are in a safe position on their side and telephone your family doctor (GP).

Make sure your child has plenty of fluid for the next 24 hours. If they go too long without drinking, then their blood pressure can drop, and they can faint.

If your child complains of feeling dizzy or faint, basic first is usually helpful:

  • Sit them down and put their head between their knees or
  • Lie them down with their legs raised
  • Offer them a sugary drink
  • Give milk only if your child does not feel sick or has vomited.
  • Your child may have mood changes which can make them irritable. This is temporary.
  • Keep a close watch on your child until they are back to normal. Do not leave them with an inexperienced carer.
  • If your child is taking any medications, please give this as normal.

Your child should be well enough to go to school a day or two after the scan. Let your child relax at home for the rest of the day (no activities).

Compiled by:
The Radiology department in collaboration with the Child and Family Information Group This information does not constitute health or medical advice and will not necessarily reflect treatment at other hospitals
Last review date:
March 2024