Inhalation Analgesia (Nitronox Gas)

Nitronox is a mixture of nitrous oxide gas and oxygen (also known as laughing gas). It is a weak anaesthetic agent, that won't cause unconsciousness on its own.⁴

The following information about the use of inhalation analgesia for pain relief in labour will assist you to make an informed decision that is in line with your preferences and values. It’s important to learn about the benefits, risks, and alternatives, and to have a discussion with your healthcare provider to answer any questions before labour begins.

• May provide some pain relief^2 3 4 especially for those unable to have an epidural or as a supplement to an epidural that is not working as well as expected⁶
• Provides similar pain relief to injectable opioids with fewer side effects⁶
• Can be used during all stages of labour, including immediately after birth if needed⁶
• Self-administered^{2 4 5}
• Starts working quickly^{2 6}
• Can be easily stopped⁶
• Allows you to keep your freedom of movement⁶
• Can reduce anxiety and increase relaxation⁶
• Assists with focus on your breathing⁶
• Short acting medication that does not affect your baby³ or your labour^{2 3 6}

Risks

• Nausea^{2 3 5 6} / vomiting^{2 5 6}
• Dizziness^{3 4 5 6}
• Drowsiness^{2 4 6} – increased in combination with narcotic analgesics⁴
• May be more difficult to breathe through a contraction with the mask on for those who feel claustrophobic, uncomfortable from the mask or have a mask phobia⁶
• Hallucinations (seeing or experiencing something that is not there)²
• Can impair your memory⁵

Alternatives

There are a variety of coping techniques you can use to manage the pain you experience during labour. Comfort measures do not involve the use of medications for pain relief. They allow you to have a better sense of control, and can result in a shorter labour with fewer medical interventions. Using comfort measures to avoid unnecessary interventions also supports your birth hormones. This will help you to have a labour that feels less intense and progresses more quickly. It also sets you up for better breastfeeding success. There is also no risk for you or your baby. See our Comfort Measures webpage for more information.

Procedure

• The gas is inhaled through a facemask or mouthpiece.^{4 5}
• The peak of pain relief happens in about 50 seconds after you start breathing the gas.⁵ It's important to start using the mask as soon as the contraction starts.

• You will continue holding the mask to your face during the contraction while breathing in and out slowly and deeply. Exhale into the mask to lessen exposure to others in the room.
• You must hold the mask yourself so that the correct amount of medication is given.⁴ Your partner or nurse cannot hold it for you.

For more information, decision aids & tools:

• Making Informed Decisions About Your Care - other decision aids & tools

If you have specific questions:

• Speak with your healthcare provider.

• If you are giving birth at LHSC – speak with the nurse at the London Health Sciences Centre (LHSC) Preadmission Clinic.