Nitrous Oxide

Nitrous Oxide

You may know this gas as happy gas or laughing gas. It is a sweet smelling, colourless gas used to ease pain and anxiety. This gas is safe for use in children and there are no long-term side effects.


Key points to remember about nitrous oxide

  • it helps to be near and to comfort your child during the use of nitrous oxide
  • this gas is safe for use in children and there are no long-term side effects
  • your child will feel more comfortable if you stay with them during the procedure

What is nitrous oxide?

You may know nitrous oxide as 'happy gas' or 'laughing gas'. It is a clear gas with no smell, used to ease pain and anxiety. It is often given at the dentist or to ease the pain of labour in childbirth.

How will nitrous oxide help my child?

Your child may receive nitrous oxide during procedures such as:

  • stitches
  • dressings
  • tube changes
  • 'moving x-ray' (fluoroscopy)

The gas helps to ease the pain and anxiety your child may feel, but usually does not make them fall fully asleep.

When your child starts to breathe the nitrous oxide, they will feel drowsy within a couple of minutes. The gas will be continued until the procedure finishes and will wear off quickly when the gas is stopped. This means your child can quickly get back to their usual activities (playing, eating etc).

How will my child receive nitrous oxide?

A doctor or nurse will give nitrous oxide to your child. A doctor will assess your child to make sure it is the best option before giving it to your child. If your child has a cold or any other respiratory concerns, then it may be reconsidered.

You will be asked to make sure your child stops eating and drinking for a certain time before they have the gas (usually at least 2 hours, but may be longer if other sedating medicines are used with the nitrous oxide). This helps reduce the risk of vomiting.

A doctor or nurse will give your child a mask or a mouthpiece attached to a machine. Your child will breathe the gas through this. It can be helpful to look at and play with the mask with your child before the procedure starts so your child is comfortable with it before it is placed on their face.

A 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 comfort them.

The best thing you can do is to stay where your child can see you and hold their hand. The gas will be given a few minutes before the procedure starts and will continue until it is finished. The gas may make your child feel 'floaty', warm and tingly but it will not make them fall asleep. Your child may or may not remember anything about the procedure.

When the nitrous oxide is stopped, your child will receive oxygen through a mask to clear the gas from their lungs. This last stage is very important. After your child has had the oxygen and is awake and alert they will be able to eat and drink normally.

Are there any risks to my child having nitrous oxide?

This gas is safe for use in children and there are no long-term side effects from occasional use.

Other side effects may occur, but they are usually minor and get better quickly. Some children feel sick or vomit during nitrous oxide sedation. The staff looking after your child will know how to manage these problems if they occur.

What can I do to help my child when they receive nitrous oxide?

The best thing you can do is to stay where your child can see you and hold their hand.

It helps if parents stay with their child to look after and comfort them during and after most procedures. 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. 

If your child asks about the procedures, reassure them and explain in simple terms what is being done and why. Always tell the truth. 

The best thing you can do is to stay where your child can see you and hold their hand.

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. 

At times it is helpful to distract your child tell by telling stories, talking about the family or anything else that may help to take their mind off the procedure. Remain calm - if you get upset so will your child. The 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.


Starship Foundation and the Paediatric Society of New Zealand acknowledge the cooperation of The Children's Hospital at Westmead, Sydney Children's Hospital at Randwick, and Kaleidoscope - Hunter Children's Health Network in making this information available to patients and families.

This page last reviewed 02 September 2020.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it