May 5, 2008

Why Isn’t Nitrous Oxide Widely Available for Labor Pain Relief in the U.S.?

I was recently pointed to an editorial in the March 2007 issue of the journal Birth which asks, “Nitrous Oxide for Pain in Labor–Why Not in the United States?” You may be familiar with nitrous oxide (“laughing gas”) as it is sometimes used during dental procedures, but as this Our Bodies Ourselves piece notes, the gas is often used in other countries as a means to control pain during labor. As the Birth editorial explains, nitrous oxide is self-administered by a woman in labor (primarily for safety reasons), allowing her to obtain a short burst of relief only when needed as an alternative to an epidural.

There isn’t a tremendous amount of research on nitrous oxide during birth, but a 2002 systematic review highlights some basic information about this technique. The authors note that the gas does not appear to affect the fetus or newborn or depress uterine contractions, although women may experience some lightheadedness and may have a slight delay in pain relief as the gas takes ~50 seconds to achieve its full analgesic effect. They also note that the gas can be both administered and stopped quickly.

Most interesting, perhaps, is this assessment of how widely use of nitrous oxide varies from country to country – “By the 1980s, use of nitrous oxide had almost disappeared in the United States. In the United Kingdom, it has been estimated that nitrous oxide is used by approximately 50% to 75% of women and in Finland by approximately 60%. Nitrous oxide is used and widely considered to be safe in many parts of the world including Canada, Australia, and New Zealand, supervised by physicians, nurses, or midwives.”

It is not entirely clear why this option isn’t more readily available in the United States. I’d be interested in hearing from readers as to whether nitrous oxide was available to you in labor – let us know in the comments! If you’re in the UK or elsewhere with common use of this option, please share your thoughts as well.

Citations for further reading:

  • Rooks JP. Nitrous oxide for pain in labor–why not in the United States? Birth. 2007 Mar;34(1):3-5.

  • Rosen MA. Nitrous oxide for relief of labor pain: a systematic review. Am J Obstet Gynecol. 2002 May;186(5 Suppl Nature):S110-26.


9 Responses to “Why Isn’t Nitrous Oxide Widely Available for Labor Pain Relief in the U.S.?”

  1. Penny Says:

    My understanding is that Nitrous Oxide is considered a workplace safety hazard for dental hygienists and others who are around it a lot:

    http://www.cdc.gov/niosh/nitoxide.html

    Maybe US hospitals would say that using nitrous in labor posed too much hazard to their employees?

  2. Rachel Says:

    Penny, you raise an interesting point, as there does seem to be a fair bit of debate in the literature about the occupational safety of the gas, and interest in using scavenging systems in dental office and hospitals that would reduce occupational exposure. Those discussions don’t seem to address the lack of availability for obstetrics patients in the first place, though.

  3. Hilary Says:

    Great post! I have wondered that myself. Two midwifery students from England did a short stint at the birth center where i trained, and they were very surprised that we didn’t use it. As far as we can figure out, there is no state health code against it, and the midwives briefly toyed with the idea of bringing it in. But, the state health code does prohibit birth centers for providing certain types of labor analgesia, so that may prohibit nitrous oxide, also. They didn’t want to push it.

  4. Heather Munro Prescott Says:

    This is only a guess, but I suspect the issue might be liability. Have their been controlled clinic studies? If not, probably folks are afraid of being sued.

  5. Jacqueline Says:

    Based on how I felt when laughing gas was used at the dentist’s, I felt too “loopy”, for lack of better word, not exactly the state of mind I want to be when I meet my child for the first time. I agree, though, let’s see some more research on this.

  6. msh Says:

    An anesthesiologist I know has this response:

    Nitrous oxide in trace amounts is considered a biological hazard. It must be scavenged, which is difficult to impossible for someone who has just been taught to self-administer while in labor.

    In a study in the 1970s, chair-side dental assistants in offices where N2O was used had higher rates of spontaneous abortion than assistants in dental
    offices where N20 was not used. That was probably why N2O disappeared in the US by the end of that decade.

    There is a tremendous abuse potential for N20, and perhaps other countries do not seek to control access, but the US does. Dentists often abuse N2O, resulting in neuropathy. N2O cylinders sitting around would be likely to be abused.

    Nitrous can be administered in a “safe” 50% mixture with O2, but the results can be highly variable and are unpredictable. Some patients get little relief,
    while the same inhaled concentration could render others unconscious. Disinhibition regularly occurs (it was described in the demonstration that gave W.T.G. Morton, one of the founders of surgical anesthesia, the idea) and can lead to dangerous behavior, such as excitation and pulling out IVs. People can have
    amnesia from N2O; while receiving it they can be screaming in pain, but later not remember. The patients and nurses at my hospital would not accept what N2O
    has to offer.

    A properly done labor epidural allows the mother to be fully sentient with well controlled pain and the ability to cooperate. N2O has some analgesic properties, but they only come with a clouding of the sensorium and risks such as combativeness, loss of consciousness, and pulmonary aspiration.

    If one wants analgesia free of risks of inhaled vapors, one can use injections of demerol, morphine, etc. These make the baby a little sleepier, but not critically so unless used in large and repeated doses.

  7. Heather Says:

    Rachel: Occupational question here.

    Do you have any idea if it’s being used in Europe for abortions, and if so, know of anywhere I can look for studies/info on that one?

    Mind, all of the %$#@!! laws flopped on providers here to make it difficult for us to provide them may still mean we can’t use it for that, but it seems like it’d be a pretty excellent option, if not, and if it’s worked elsewhere.

  8. Rachel Says:

    Heather, that’s a great question, and one I don’t know the answer to off the top of my head, although I’ll see what I can find. I would normally recommend EMBASE as a starting point and some double-checking in PubMed for this question, but EMBASE is subscription-only. I’ll take a look.

  9. Jessica Says:

    I am an American nurse who has lived and worked, and given birth to two children in the UK. I have recently moved back to the States, and am very interested in why Nitrous (or ‘gas and air’ as we call it in the UK) isn’t available in the US. During my first pregnancy I planned on, and was relying on an epidural to be my pain relief method of choice. During my induction I had two epidurals fail, with no explanation as to why. The placement and removals of the failed epidurals made me EVEN MORE uncomfortable and frightened. I ended up relying on diamorphine and gas and air. The morphine knocked me out and allowed me to rest, but it was the gas and air that kept me calm and saw me through until my baby was finally born. During my second labor, I relied soley on nitrous. I was able to move and to walk, the gas kept me calm, and after the birth I was able to move around and bathe immediatly. In the UK gas is considered very safe..like not having pain relief at all. It certainly worked for me, and I would very interested in any future research studies, or possibly an authoritive expalnation of exactly why it’s not used if such an explanation already exsist. It seems that any occupational risks could be recognized and minimized, for the sake of an effective alternative to epidural and opiod analgsia which have been proven to have multitudes of serious side effects.

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