Is it true that laughing gas is not used to reduce labor pains because it is cheap?
There seems to be a range of factors contributing to why N2O is not readily available in the US.
Nitrous Oxide for Labor Analgesia: Expanding Analgesic Options for Women in the United States
One major barrier to implementation of N2O services in the United States has been the limited availability of N2O delivery equipment. The device must be equipped with a demand valve capable of intermittent high-volume delivery capacity. Most commercially available N2O analgesia systems, such as those used in the dental industry, employ continuous-flow low-volume systems and are unsuitable for intermittent use with laboring women. As previously mentioned, single-cylinder Entonox systems used in Europe have not been approved for use by the FDA and are not available for purchase in the United States. Currently, Nitronox is the only FDA-approved apparatus for the self-administration of N2O. Matrx Medical (Orchard Park, NY), the initial manufacturer of Nitronox equipment, discontinued production several years ago, which made the purchase of new units impossible. Recently, however, the Porter Instrument Division of Parker Hannifin Corporation has secured the rights to manufacture the Nitronox apparatus, and have indicated that they intend to have a device on the market by the end of 2012 (M. Civitello, personal communication, June 2012). Reintroduction of Nitronox equipment will remove a major barrier to N2O availability.
Of course it could be argued that the reason the equipment isn't available is because there is no demand. And the reason there is no demand is because hospitals don't want to buy new equipment that will reduce their profits. So let's keep going.
Are there other reasons why an epidural may be preferable?
Nitrous Oxide for the Management of Labor Pain(300+ pg pdf)
Inhalation of nitrous oxide provided less effective pain relief than epidural analgesia,
but the quality of studies was predominately poor. The heterogeneous outcomes used to assess
women’s satisfaction with their birth experience and labor pain management made synthesis of
studies difficult. The strength of evidence was insufficient to determine the effect of nitrous
oxide on route of birth. Most maternal harms reported in the literature were unpleasant side
effects that affect tolerability (e.g., nausea, vomiting, dizziness, and drowsiness). Apgar scores in
newborns whose mothers used nitrous oxide were similar to those of newborns whose mothers
used other labor pain management methods or no analgesia. Evidence about occupational harms
and exposure was limited.
...
One concern with nitrous oxide use is the potential for the gas to escape into the room and
potentially affect health care workers as well as other individuals present with laboring women.
For this reason, multiple organizations are responsible for regulating the use of nitrous oxide, and
factors other than clinical outcomes are important to decisionmaking about its use (Appendix F).
Room ventilation systems and scavenging systems that remove waste gases are used to reduce
exposure to caregivers and others present for labor. Equipment capable of scavenging provides
constant negative pressure so that the woman’s exhalations, which contain nitrous oxide, are
captured and removed from the room and facility.6
There seems to be reasons for and against the use of N2O (though the study seems somewhat supportive). Either way, it's not exactly a no-brainer.
Laughing Gas For Labor Pain — Why Not?
Holly Powell Kennedy, Ph.D., a certified nurse midwife and professor of midwifery at Yale University School of Nursing, says one of the reasons nitrous isn’t used in the U.S. is simply cultural. Many women make decisions about childbirth based on what they learn from family and friends, and most have never heard of or used nitrous oxide for coping with labor pain.
Alright, well that makes sense. But couldn't they still be conspiring against us? Well, we'll probably never know, but this article seems to give us a peek inside the important factors in hospital decisions.
The role of pharmacoeconomics in formulary decision-making
The role of cost- and pharmacoeconomic-related criteria in formulary decision-making was assessed in a literature review of 31 studies of hospital (n=18) and managed care (n=13) pharmacy and therapeutics (P&T) committees. In both settings, cost was important, although the elements of cost considered varied. Acquisition cost was mentioned more frequently than pharmacoeconomic or cost-effectiveness information. Other factors, including drug characteristics, quality of life, supply-related issues, and physician demand, also influenced decisions. Despite the relatively low reported usage of pharmacoeconomic data in decision-making, most respondents considered the information to be "somewhat" or "very" important. Barriers to the use of pharmacoeconomic information included institutional factors and lack of training. Limitations in the survey methods used and issues considered restricted the ability to identify a comprehensive and consistent role for cost information in selecting formulary drugs. Further research on the use of pharmacoeconomic information is required. (Formulary. 2006;41:374–386.)