Nitrous Oxide During Labor
- How nitrous oxide during labor can provide pain relief
- What studies have found about the safety and effectiveness of nitrous oxide during labor
- The potential pros and cons of using nitrous oxide during labor
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- Hellams, A., Sprague, T., Saldanha, C., et al. (2018). Nitrous oxide for labor analgesia. JAAPA. 2018 Jan;31(1):41-44.
- Klomp, T., van Poppel, M., Jones, L., et al. (2012). Inhaled analgesia for pain management in labour. Cochrane Database of Systematic Reviews, Issue 9. Art. No.: CD009351.
- Likis, F. E, Andrews, J. C, Collins, M. R, et al. (2014). Nitrous oxide for the management of labor pain: a systematic review. Anesth Analg;118:153–67.
- Onody, P., Gil, P. and Hennequin, M. Safety of inhalation of a 50% nitrous oxide/oxygen premix: a prospective survey of 35 828 administrations. Drug Saf. 2006;29(7):633-40.
- Richardson, M. G., Lopez, B. M. and Baysinger, C. L (2017). Should nitrous oxide be used for laboring patients? Anesthesiol Clin. 2017 Mar;35(1):125-143.
- Sanders, R. D, Weimann, J. and Maze, M. (2008). Biologic effects of nitrous oxide: a mechanistic and toxicologic review. Anesthesiology;109:707–22.
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What is nitrous oxide?
Nitrous oxide is a medical drug approach to pain management during labor. It’s a mixture of nitrous oxide, N2O, and oxygen. It’s sometimes called laughing gas, and it’s used commonly in dental procedures around the world.
Nitrous oxide is a systemic drug, so it reaches your whole body. It’s also an inhalant, so it’s something you inhale through a mask. It’s supposed to help manage pain throughout the whole body without causing a total loss of feeling or any loss of muscle movement.
How common is nitrous oxide during labor?
Nitrous oxide is used for pain management during labor in many countries around the world, including the United Kingdom, Australia, and Canada. It’s been used in labor for pain management for more than a hundred years, but it’s still pretty rare in the United States.
However, in the past few years it’s started growing in popularity. In 2017, researchers said that it was offered in at least 150 hospitals and 50 birthing centers in the US. A survey of 2,400 people who gave birth in the US in 2011 and 2012 found that only 6% of them used nitrous oxide during labor.
How is nitrous oxide used during labor?
Nitrous oxide is a tasteless, odorless gas that’s easily given through a mask that the laboring person holds over their nose and mouth. You have to learn how to time your inhales with your contractions. For maximum pain management, you should actually start inhaling about 30 to 45 seconds before your contraction begins so that the drug peaks at the same time your contraction is peaking. It’s recommended that your oxygen levels be monitored continuously while you’re receiving nitrous oxide. Only one nitrous oxide gas delivery system has been approved by the FDA in the US, and it’s called Nitrinox.
What is the research evidence on nitrous oxide during labor?
There have been three research reviews where researchers have collected all of the research on the topic of nitrous oxide and published papers about it. The first one was published in 2007. In this review, they looked at 140 different studies where nitrous oxide had been used for a variety of reasons, including dental procedures and childbirth. They concluded that this drug is extremely safe when it’s used in clinical settings. They found that serious side effects occurred in about three out of 10,000 people. Using the best quality study, they found 27 cases of side effects in about 36,000 people who used the drug. Only nine of those side effects were thought to be caused by nitrous oxide, and although they called them “serious,” they were things like drowsiness and vomiting, so they really didn’t seem that serious.
In 2012, researchers published a Cochrane review looking at 26 studies that had a total of about 3,000 participants. In this study they compared people who had nitrous oxide during labor to people who had something called a flurane derivative. People who used the nitrous oxide actually had worse pain management compared to people who used flurane derivatives. People who used nitrous oxide had more severe pain, more intense pain. People who used nitrous oxide also had more nausea than the people who used flurane derivatives. Flurane derivatives are a type of gas, and it’s probably not used very often today, even though it was shown to be more effective, because it tends to have an offensive odor.
When the Cochrane researchers looked at the studies that compared nitrous oxide to placebo or no treatment, they found that nitrous oxide provided better pain relief than placebo, but more drowsiness, dizziness, nausea, and vomiting. They were no difference in Apgar scores or cesarean rates between people who used nitrous oxide and those who had a placebo or no treatment.
Finally, there was a review published in 2014. This review found 58 studies, but they said that most of them, 46, were of poor quality. 32 studies in this review looked at the effects of nitrous oxide on maternal health. Using the best quality evidence, the authors estimated that with nitrous oxide, 13% of laboring people will have nausea or vomiting, 3 to 5% will have dizziness, 4% might feel drowsy, 18% might have a reduced sense of awareness, and about 5% will feel mask phobia where they feel claustrophobic because of the mask being on their face.
In this review, 29 studies looked at the effects of nitrous oxide exposure on the health of the baby. They found no difference in Apgar scores or the rate of NICU admissions between babies whose mothers used nitrous oxide and those who did not.
Pros of nitrous oxide during labor
Let’s talk overall about the pros of nitrous oxide. Access to nitrous oxide can provide more pain management options for people who do not have access to an epidural or who do not want an epidural. According to patients’ reports, nitrous oxide provides about a similar level of pain relief as compared to an injectable opiod, but it doesn’t carry those side effects for the newborn that you see with injectable opioid drugs. Although mothers report that the nitrous oxide is less effective than an epidural, people who have nitrous oxide report about similar satisfaction levels compared to people who have an epidural. And most people who use nitrous oxide say they would use it again.
Nitrous oxide can be used during all stages of labor, even after the birth, like for example, if you’re having a perineal tear repaired, you could use nitrous oxide during that time. Nitrous oxide is very versatile. It can be stopped at any time, started at any time, or switched to something else at any time. It can be used to supplement an epidural that isn’t working very well or it could be used to help you if you’re having to wait for an epidural- if the epidural isn’t immediately available.
The pain relief with nitrous oxide starts working in about a minute, which is less time than you would have to wait with an epidural. It’s also less invasive than using an epidural or injectable opioids. One of the things that people like about nitrous oxide during labor is that they can use the mask to control their own pain relief. They can choose when to put the mask on and when to take it off. It might increase their sense of perceived control which can reduce pain perception. Also, nitrous oxide lets you keep your strength and freedom of movement. It might create a sense of pleasure and relaxation. Also, it can ease your anxiety. Some midwives tell me that it’s not that effective for managing pain, but one of its main benefits is that it really relaxes people so they don’t care about the pain as much.
Also, when you’re using nitrous oxide you’re really focusing on your breathing, which may help to explain some of its beneficial effects. It’s simple and inexpensive and has not been shown to increase bad health outcomes for mothers or newborns.
Cons of nitrous oxide during labor
The main drawbacks to nitrous oxide during labor is that it’s less effective than other forms of pain management. It’s definitely less effective than an epidural. Also, it requires repeated self-doses, so you have to hold the mask to your face when you want the pain management. Some people, if they’re exhausted or tired, might not want to have to keep doing that.
It can also give you a sense of detachment, like feeling as though you’re not really present. It may make you feel sleepy, dizzy, nauseous, or you might even feel a sense of claustrophobia from the mask.
One set of researchers expressed concern that nitrous oxide can disrupt cellular processes in both the mother and newborn for several days. However, the long-term impact of this is not really understood.
Because 99% of nitrous oxide that you inhale comes out when you exhale, 99% of it is still there in the room, so care providers have to be careful not to be over-exposed to it. However, if you breathe back into the mask, that helps to contain the gas. Also, there are other safety precautions that care providers can take to monitor or reduce their exposure.
In summary, nitrous oxide appears to be safe for labor and has a long track record of use during labor and dental procedures. However, there are very few studies of good quality on this subject. More research is needed on potential bad side effects, including long-term side effects. We need more research on maternal satisfaction and effectiveness.
One of interesting things is that people who use nitrous oxide report really high satisfaction with their births even though the effect on their pain isn’t really that good. It’s possible that pain relief might not be the best measure of success with nitrous oxide. It’s not really intended to relieve pain so much as to help people cope with the pain. For some people, a less effective pain relief strategy, but one that helps them cope with pain and avoid other interventions, might be an approach that they want, especially if it gives them more control and more freedom of movement.
That’s the evidence on nitrous oxide. I hope you enjoyed this video. Feel free to check out our other videos all about pain management strategies during labor and childbirth. Thanks, and bye. To learn more and subscribe to our newsletters for useful information, please visit EvidenceBasedBirth.com.
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