Nitrous oxide therapy factsheet

Introduction

Nitrous oxide is a gas used to help children stay calm and manage pain during small scans or procedures. It is also called happy gas or laughing gas.

Nitrous oxide therapy can be used to help with:

Preparing for treatment

Talk to your child’s treatment team about whether nitrous oxide therapy is suitable. It can only be used for certain procedures and may not be right for every child. 

The treatment team will need to check that:

  • the procedure is suitable for nitrous oxide therapy
  • your child is well and can breathe without issues
  • your child can stop eating and drinking before the procedure to lower the risk of vomiting.

They will discuss with you all options to help keep your child calm and as pain-free as possible.

During the treatment

Nitrous oxide therapy is given a few minutes before the procedure starts and continues during it.

The gas is mixed with oxygen and given through a face mask or mouthpiece. A doctor or nurse will help secure the mask around your child’s mouth and nose before telling them to start breathing in deeply.

As your child breathes, they will feel relaxed and sleepy. They should not fall asleep.

After the treatment

When the procedure is finished, the gas is turned off and your child will breathe only oxygen. This helps clear the gas from their lungs.

Your child should feel normal soon after. They can usually eat, drink, and go back to normal activities.

Some children may not remember the procedure or anything that happened while they were having the nitrous oxide therapy.

 Management

Side effects of nitrous oxide therapy

Nitrous oxide is safe when given by trained staff. There are no long-term side effects when used correctly.

Short-term side effects can include:

  • nausea and vomiting
  • headache
  • dizziness
  • feeling weak.

These usually stop soon after the gas is turned off. Staff will help manage any side effects and keep your child comfortable.

Supporting your child during nitrous oxide therapy

Nitrous oxide usually makes children feel calm and sleepy. Some may feel silly or light-headed. Others may feel sick or uncomfortable wearing a mask.

Some children may feel upset, distressed, or angry and may try to take off the mask or mouthpiece.

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

Ask your child’s treatment team about strategies to support your child. These may include:

  • telling stories or singing
  • watching a video
  • using a phone app or game
  • playing with a toy
  • practising with the mask before the procedure.

Disclaimer

This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2025


This factsheet was produced with support from John Hunter Children's Hospital.