Updated: Dec 19, 2019
NITROUS OXIDE IN LABOR
You’ve probably heard of IV analgesics and regional anesthesia (like epidurals) for labor, but have you learned anything about Nitrous Oxide (laughing gas) as a pain relief option? It’s a drug option that has been around for hundreds of years. It is slowly starting to gain traction again in the U.S. as a viable pain management option, after falling out of favor for decades.
What is Nitrous Oxide?
Nitrous Oxide (aka laughing gas) is a tasteless, odorless inhalant used as a pharmacological approach to reducing labor pain. It’s been around for quite a long time, first being discovered in 1772. Later, in the 1850s, Queen Victoria of England popularized its use after she used it during two of her births. In the U.S., Nitrous Oxide has been used for labor pain since around 1900, but its used declined significantly by the mid 1950s as more powerful anesthetics were developed. Finally, by 1970 the rise of epidural anesthesia, allowing for women to be awake but relatively pain free during their births sent Nitrous Oxide to the back burner of pain management options for a number of years.
In higher concentrations, nitrous oxide is a weak anesthetic, used commonly for dental work. In lower concentrations, such as used in labor, it acts as an anxiolytic (a drug used for anxiety relief) and an analgesic (a drug used for pain relief). Nitrous Oxide used in labor is a concentration of 50% Nitrous Oxide and 50% Oxygen. Unlike going to the dentist, the dose for labor is set and can not be titrated up or down.
How Do I use Nitrous Oxide?
After signing consent forms with your OB/GYN or Certified Nurse Midwife, your nurse can easily set this up for you in your labor room. It is self-administered through a mask that you hold sealed around your mouth and nose. Timing the use of the Nitrous Oxide is important. Most women find it best to begin inhaling just before the contraction begins, to allow the gas to really be of value during the peak of the contraction. From there on you can use it as you see fit. With every contraction, with every other contraction, or whatever works for you!
The demand valve on the mask ensures that when the mask is not being held to your face, you are not getting a dose of the drug. With that said, what you do exhale outside of the mask does go into your labor room's air, so your hospital providers will most likely instruct you to exhale directly into the mask.
***Of note, well-meaning family and friends in your labor room are NOT to be touching your mask. This is a safety net in place to ensure that you receive only the amount that you need to cope with the contraction pain and avoids potential side effects such as dizziness and nausea and so that you don't pass out!
How effective will it be for my labor pain?
I'm not going to sugar coat it, this varies from woman to woman. Unlike an epidural, laughing gas is not going to numb any area of your body, and will not significantly relieve your pain like an IV narcotic does. Most women describe it as “taking the edge off” or as a distraction from the pain. You may at times feel slightly lightheaded, giddy, or briefly dizzy. The good news is, if this option is not working well for you, there is nothing that would preclude you from getting additional pain medication on board. As an added bonus, while waiting for the next intervention, such as an epidural, you could use your mask during contractions to cope with your pain and remain calm during the procedure.
Advantages of Nitrous Oxide Use
Quickly administered once requested
Fast onset and clearance from your body
Can be used during all stages of labor – including during perineal repairs
May give you a sense of relaxation, drowsiness, or calmness during contractions
Not known to have any effect on breastfeeding, newborn bonding or newborn resuscitation, though studies in the U.S. are limited
Not known to reduce your risk for a vaginal birth
Doesn’t interfere with oxytocin production, so therefore has no known side effect on your uterus or contraction pattern
Mobility is not really inhibited. You may need to be seated in your bed or on a birth ball or chair (in case of dizziness) during contractions, but in between you can be up and moving around
Depending on hospital policy, continuous electronic fetal monitoring may or not be required
Depending on hospital policy, IV placement may not be required
What are the disadvantages?
If you go against hospital policy and do allow a family member to hold the mask to your face, you could pass out
Nausea and vomiting are possible side effects
You will need to be close to a wall in the hospital room to allow for the gas apparatus to be plugged in (somewhat mobility limiting)
You may not have the same effects of more complete pain relief as with other options, such as an epidural
Depending on your labor circumstances, you may be exhausted and not want to hold the mask to your own face repeatedly
Are there contraindications for it?
You can’t hold your own mask to your face
You have a B12 deficiency (Nitrous Oxide and its depletion of your B12 levels is associated primarily with long- term use, but if you’re known to be B12 deficient, should be avoided). Either have a 3rd trimester blood draw documented on your prenatal record, or ask hospital to draw a B12 level on admission if you’ve been considering Nitrous Oxide use and have risk factors for B12 deficiency or a history of pernicious anemia
You have had recent inner ear surgery (the drug can cause increased inner ear pressure)
You have acute drug or alcohol intoxication
You have Chronic Obstructive Pulmonary Disease (COPD)
Other rare contraindications would be assessed for during your health assessment prior to administration with your providers.
Nitrous Oxide is gaining attention once again in the US as another viable pharmacological tool for labor pain management. It's not available everywhere, so if it's something you think you may be interested in, it's best to talk with your healthcare providers in advance about it's potential use and availability at the facility you plan to deliver at. While it's not necessarily the most effective pain relief option for labor, it has definite advantages over other pain management options in terms of mobility, sedation, labor progress risks, and potential implications on your newborn, so it's definitely worth checking out and giving it some genuine consideration.