Nitrous oxide

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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What is nitrous oxide?

You may know nitrous oxide as ‘happy’ gas or’ laughing’ gas. It is a clear and odourless gas used to ease pain and anxiety. It is often given at the dentist, or to ease the pain of labour.

How will it help my child?

Your child may be given nitrous oxide gas to help ease pain and help them to relax during procedures such as:

  • stitches, 
  • dressings,
  • tube changes or
  • fluoroscopy procedures such as Micturating Cysto Urethrogram (MCU).

The gas is given through a face mask or mouth piece by a doctor or nurse. As your child starts to breathe in the gas they may start to feel drowsy and relaxed, although the gas does not make them fall asleep.

The gas is given for the length of the procedure and wears off quickly, which allows your child to get back to their usual activities such as such as eating, drinking, playing etc. Your child may or may not remember anything about the procedure.

How will it be given?

Before nitrous oxide is given, your child will need to be assessed to make sure this is the best option. Generally if your child has a cold or any other respiratory concerns, then it may be reconsidered.

If it is considered appropriate to proceed, you will be asked to make sure your child stops eating and drinking for a certain time, prior to having the gas. This helps to reduce the risk of vomiting. The fasting time is usually at least two hours prior to procedure. This may need to be longer for some procedures or if other sedating medicines are being used with the nitrous oxide.

The gas will be given a few minutes before the procedure starts and will continue until it is finished. When the nitrous oxide is stopped, your child will then be given oxygen through the mask, this helps to clear any remaining gas from the lungs. This stage is very important as after the oxygen is administered your child will feel more alert and be able to get back to their usual activities and eat and drink normally.

What to expect?

The nurse or doctor may need to hold the mask firmly over your child’s face at first. This is until the gas starts to work and your child relaxes. Some children may not like the mask on their face, it may make them feel confused or angry so it is important for you to stay close to them and give comfort.

The gas may make your child feel "floaty", warm and tingly but it will not make them fall asleep.

Are there any risks?

Nitrous oxide has been used safely in children for many decades. There are no known long-term side effects in otherwise well children who receive brief exposures.

Some children may feel sick and, on the rare occasion, vomit during nitrous oxide sedation. If this does happen the staff looking after your child will know how to care for your child.

In a small number of very rare conditions, nitrous oxide should be avoided. 

What can I do to help?

  • We encourage parents to stay with their child, to help give support and comfort to them. If you feel you are unable to be there, think about asking another adult who your child is comfortable with to be there on the day.
  • The best thing you can do is to stay where your child can see you and hold their hand.
  • Research has shown that distraction is helpful in reducing pain and anxiety during procedures. Distraction involves helping your child to focus on things other than the medical procedure; for example, telling stories, talking about family or anything else that may help take their mind off the procedure. You could, look at picture books, watch a DVD, play an app, sing a song or play with other favourite toys.
  • If the opportunity arises, it can be helpful to look at, and play with the gas mask with your child, before the procedure starts so your child is comfortable with it, before it is placed on their face.
  • Staff are there to help you and your child. If you would like more information please ask the nurse or doctor caring for your child.


  • Your child will feel more comfortable if a parent or carer stays with them during the procedure.
  • Be honest and calm when informing your child about the procedure and answering questions. It is usually helpful to bring your child’s comfort toys or items which help them relax. For example a teddy, dummy, blanket, book, a phone/IPAD with a favourite game. These familiar items can be very comforting.

If you would like further information on providing support to your child during procedures, or if your child has frequent procedures and experiences anxiety please make contact with your local hospital’s Child Life Therapy Department at:

  • Sydney Children’s Hospital, Randwick - 93826984
  • The Children’s Hospital at Westmead - 98453717
  • John Hunter Children’s Hospital – (02)49855410
The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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