Nitrous Oxide

Nitrous Oxide

Nitrous oxide is also known as happy or laughing gas. It is a gas that can be used to help tamariki (children) with small scans or procedures that might be stressful or painful.


Key points 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?

Nitrous oxide is a gas that can be used to help tamariki with small scans or procedures that might be stressful or painful. It is also known as happy gas or laughing gas.

How will nitrous oxide help my child?

Your child may receive nitrous oxide during procedures such as:

  • getting stitches to close a wound
  • cleaning and dressing a wound
  • changing feeding tubes
  • certain types of scans

How can my child prepare for having nitrous oxide? 

You will need to talk to your child’s treatment team about nitrous oxide therapy before the procedure or scan. Nitrous oxide can only be used in some kinds of scans and procedures. It is not suitable for all tamariki. 

The doctor will check that:

  • nitrous oxide is OK for the procedure your child is having
  • your child is well with no breathing issues
  • your child can stop eating and drinking before the procedure to lower the risk of vomiting.

Your child’s doctor will speak to you about all options for keeping your child calm and as pain-free as possible.

What happens while my child is having nitrous oxide?

Your child will start having nitrous oxide gas a few minutes before their procedure or scan starts. They will continue having it until the procedure or scan has finished. 

A mixture of nitrous oxide and oxygen gas will flow through to a face mask or mouthpiece. A health professional will help secure the mask around your child’s mouth and nose before telling them to start breathing deeply.

Your child will feel sleepy and relaxed as they breathe the gas. The gas should not make your child fall asleep.

What happens after my child has had nitrous oxide?

The gas will continue to flow until the procedure or scan is finished. The health professional will turn off the nitrous oxide but continue giving oxygen through the mask. This is to help clear out any remaining nitrous oxide from the lungs.

Once the oxygen starts to flow, your child will become more alert and awake. They should be able to return to normal activities straight away, including eating and drinking.

Some tamariki will not remember anything about the procedure after having the nitrous oxide gas.

Are there any side effects from having nitrous oxide?

Nitrous oxide therapy is safe when given by a trained health professional. There are no long-term side effects when used appropriately during scans or procedures.

Short-term side effects can happen during and after nitrous oxide therapy. 

Side effects can include: 

  • nausea and vomiting
  • headaches
  • feeling dizzy
  • feeling weak

These side effects should stop soon after the gas is stopped. A health professional can treat any side effects and help your child feel comfortable.

How can I support my child while they are having nitrous oxide? 

Nitrous oxide gas will usually make your child feel relaxed and sleepy. Some tamariki might feel funny and silly, while others might feel sick.

Some tamariki do not like having to wear a mask or mouthpiece. They may feel upset and angry and might try to take the mouthpiece or facemask off.

Parents and carers are encouraged to stay with their tamariki to help them feel safe and supported.

Speak to your child’s treatment team about different strategies that can be used and whether they can be used during your child’s scan or procedure. 

Strategies can include:

  • telling stories and singing songs
  • watching a movie or TV show on your phone
  • playing with an app
  • playing with a favourite toy
  • playing with the mask or mouthpiece and trying it on before the procedure starts.

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 24 June 2024.

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