Nitrous Oxide
Nitrous oxide is a colorless, odorless and tasteless gas used to decrease pain. The PRO-NOX system is a blended mixture of 50% nitrous oxide and 50% oxygen managed by the patient by inhaling through a mask. This blend of nitrous oxide is unlike the higher-dose version commonly used by dental practices and often referred to as laughing gas.
Are there any reasons I could not use nitrous oxide?
Yes. You cannot use it if you:
- Cannot hold your own mask
- Are less than 35 weeks gestation
- Have received an IV dose of opioids within the past two hours or IM opioids within the last four hours
- Have a known vitamin B12 or folate deficiency or known MTHFR gene variant
- Have a known history of pneumothorax or emphysema
- Have taken Methadone or Suboxone in the last five days
- Have had a recent head trauma within the last two weeks
- Are currently receiving IV magnesium sulfate
- Have impaired consciousness
The use of nitrous oxide during labor and my responsibilities
- You will inhale nitrous oxide through the mask provided. You must hold your own mask, which allows you to decide when to use it and how much you need.
- It is important that you exhale directly into the mask to protect hospital staff and your support person(s) or visitors from being exposed to the gas.
You must be the only person holding the mask to your face to administer nitrous oxide
No one else can hold the mask to your face. This allows for the administration of nitrous oxide only when you require it for pain relief. The risks of someone else holding the mask to your face include over-sedation, airway block and decreased oxygen to you and your baby. If staff observe others helping with the administration or being used by anyone other than the patient, the nitrous oxide system will be discontinued and removed from your room.
How much does nitrous oxide help with labor pain?
How well nitrous oxide works depends on the individual. For some, it “takes the edge off” the peak of the contraction and reduces anxiety, allowing them to better cope with labor. If you do not like the way nitrous oxide makes you feel and/or do not find it helpful, you can choose to try other pain relief options. They are still available after using nitrous oxide.
Will it affect my baby?
Nitrous oxide does cross the placenta to the baby, however, there are no known immediate effects on the baby. Studies have not shown adverse effects on Apgar scores, newborn blood gas levels or on newborn behavior and nitrous oxide has been used for decades in laboring individuals. The laboring body clears nitrous oxide through the lungs in about five minutes. This includes nitrous oxide that passes through the placenta.
How will it make me feel and what are the side effects?
You might feel drowsy, lightheaded or a little silly while you are using nitrous oxide. Some patients have reported restlessness, confusion and nausea after prolonged use. There are medications that can be given to help alleviate nausea, if necessary.
If you inhale too much gas, it is possible to faint (pass out or lose consciousness) temporarily. That is why it’s important that you are the ONLY person holding the mask. When your body has received enough gas, your hand will naturally fall away from your face.
Most side effects go away quickly once you stop inhaling the gas.
Can I be out of bed or in the tub while using nitrous oxide?
Yes, with assistance from staff you may get out of bed. Due to possible side effects that may increase your chance of falls, we ask that you have someone with you for safety when you are out of bed or in the tub.
If I use nitrous oxide, can I still get an epidural if I want to?
Yes. You may choose to use nitrous oxide prior to having an epidural placed, or before choosing another method of pain relief. However, they will not be used together at the same time.
If you have additional questions about the use of nitrous oxide during your labor and delivery, please talk with your provider.
