Nitrous Oxide for Labor Analgesia presented by Sandy Hoffman, MS, RNC-EFM and Debbie Biffle, BSN, RNC, NE-BC

1. Nitrous Oxide for Labor
Analgesia
Sandra Hoffman MS RNC-EFM
Debbie Biffle BSN RNC NE-BC
ANW Innovation Summit 2016

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Acknowledgement and Thank You to The Abbott
Northwestern Foundation for support of nitrous oxide
for labor analgesia research!
Thank you to Dr Susan Sendelbach-ANW Director of Nursing
Research for project assistance!
• Sandra Hoffman has no disclosures
• Debbie Biffle has no disclosures
Images in this presentation are public domain images
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Disclosures and Acknowledgments

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OBJECTIVES
• Discuss nitrous oxide use for labor analgesia
• Describe candidates for nitrous oxide, and
contraindications for use
• Describe nursing research regarding nitrous oxide for
labor analgesia

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Nitrous Oxide at the Present
• Most utilized gaseous anesthetic worldwide
• #1 utilized modality for labor analgesia worldwide
• UK- 60% of laboring women utilize N20
• Australia- 50% utilization
• Norway- offered at 85% of birthing centers
• Finland- 48% utilization
• More common than regional anesthesia worldwide
(Rooks, 2007; STAKES 2006)
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& in the United States…
UCSF (over three decades)
Vanderbilt (over 10 years)
Only recently widely available in
the Twin Cities (Birthing centers
and hospitals)
Growing consumer interest….
ANW program started May 2016
Long history of safe use- over 50
years!
Why has it taken so long to catch on
in the US?

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• 61% of women who have singleton vaginal
births in the U.S. receive regional anesthesia for
labor pain. Epidurals are the most effective
pain mgt modality.
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Nitrous Oxide: Why so long to adopt?

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• All women do not need or want regional anesthesia.
Those who do are may be denied accessibility due to
lack of or competing needs for the services of anesthesia
professionals.
• This is especially true for women living in rural areas and
delivering in institutions where anesthesia may not staff
24/7.
(Rooks, 2007)
Nitrous oxide may become increasingly in demand as the supply
of anesthesiologists and nurse anesthetists to provide 24/7 access
to labor epidurals and the need for some kind of relatively
effective analgesia during labor (Rooks 2010)
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Nitrous Oxide

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Women want choices!
• Great adjunct for natural childbirth because it does not
affect the fetus like narcotic analgesia
• Does not have the numbing effect of an epidural
• Has a calming effect which is helpful to relieve anxiety
during labor
• Some women are not candidates for epidural

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Nitrous Oxide: What is it??
• Commonly known as “laughing gas”
• Colorless, tasteless, non-flammable gas
• Liquid at room temperature
• Self administered- patient holds the mask
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50% Nitrous Oxide/50% Oxygen used in
labor is analgesia-not anesthesia!
• Analgesia or “minimal sedation” per American
Society of Anesthesiologists (ASA)
• No special regulations or guidelines-”minimal
risk”
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• Patient awake and alert
• Protective laryngeal reflexes intact
• Self administration
• Effect titrated by frequency and intensity of
inhalation
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Analgesia…NOT Anesthesia

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According to the ACNM Position Statement on Nitrous
Oxide 2010… “Women should have access to a variety
of approaches to promote comfort and reduce pain
throughout labor”

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• Rapid onset/offset
• Low cost
• Can be given at any point in labor
– (never “too late”)
• Does not diminish contractions or slow labor
• No impact on the ability to push
• No known effect on fetal heart rate or newborn APGARs
• Allows for intact, but lessened, sensation of labor and
birth
– (which is desired by many women)
• Procedural analgesia option: repairs, manual removal,
manual OP rotation, tamponade balloon placement
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Advantages

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Nitrous Oxide Advantages
• Easy to set up quickly, and teach the patient how to
use. Self administered
• Option for women who want minimal intervention,
rapid onset of action
• May be able to postpone or avoid narcotics or
epidural
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Nitrous Oxide Mechanism of Action:
How Does it Work?
• Nitrous oxide works by reducing the perception of
pain and lowering anxiety levels.
• Resulting euphoria and dissociation may make
pain more manageable.
• The ability to self administer nitrous oxide may
help the woman feel more in control of pain
(Zauderer 2016)
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Nitrous Oxide
Is it safe for the fetus or newborns?
• Potential neurotoxicity of anesthetic agents has
been topic of interest in recent years
• phenomenon called “apoptosis” seen ONLY in animal studies when exposed to
extreme amount over long periods of time
• Also applies to sedatives, hypnotics, narcotics, and all anesthetic
gases
• Nitrous oxide is one of a very long list of agents of interest in this
regard
• Studies have not shown an effect on the fetal heart rate,
breastfeeding, APGAR or behavioral assessment scores
11/7/2016

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• Can be used in any stage of labor, no time limit
established in the literature
• Normal low risk patients >-37 weeks gest.
• Initial electronic fetal monitoring tracing reflects
adequate oxygenation.
• Contraindications: Vit B12 Deficiency, narcotics in
the last 2 hours, drug use or intoxication, respiratory
compromise, pt can’t hold own mask, etc.
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Who may use Nitrous Oxide?
(Allina)

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Equipment
• Portable tanks (N20 and 02) or may use wall O2
• Blender device mixes 02 and N20 to
deliver a set 50:50% concentration
• Self administration by face mask with a demand
valve-only get the nitrous by inhalation
• Patient exhales into the mask, scavenging system
filters and diverts exhaled gas to wall suction.
Not exhaled into room air

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Patient/Family Education
• Intermittent vs continuous use
• Peak analgesic effect lags the start of it’s
administration by 50 seconds, uterine
contractions typically peak 30 seconds after they
start
• Educate that may not provide complete pain relief
• Elimination quickly via lungs (elimination half life
5 min)
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• The effects on human fetuses or in children later
in life who were exposed to nitrous oxide or
other anesthetic agents in utero are unknown.
• Low concentrations and brief period to which a
fetus would be exposed during labor (even a
prolonged one) would be unlikely to result in a
measureable effect even if such effects were
later shown to be real.
(Starr and Baysinger, Anesthesiology.theclinics.com 2013
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? Neurotoxic effects

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• There is a general lack of US data on maternal and
fetal outcomes, and a specific lack of data on:
-sense of control/satisfaction with the childbirth
experience
-effect on mother/baby interaction
-breastfeeding
-admission to special care nursery
-infant outcomes at long term follow up
-costs
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The Need for Research

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• ANW Foundation Innovation Grant Awarded June
2016!
• Project collaboration: St Catherine University, Dr
Jane Wrede-Bethel University Midwifery Program
Director
Research Question: Is there a difference in maternal
characteristics and/or maternal and newborn
outcomes when women have received nitrous oxide
or received nitrous oxide continuously or
intermittently
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Abbott Northwestern Nursing
Research

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• Describe the characteristics of women who choose
nitrous oxide for labor versus those who do not
(age, parity, ethnicity/race, delivery type, doulas,
provider type, type of insurance)
• Maternal outcomes (pain scores, vacuum or forceps,
vaginal lacerations, delivery type, length of first and
second stage labor, length of stay)
• Newborn outcomes (APGAR scores, nursery
disposition, cord blood gas results if obtained,
resuscitative measures)
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Study Aims

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Some Data……..

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Nitrous Oxide
In Conclusion:
• Nitrous is a great option for many laboring women
– Many women will desire and appreciate
• Nitrous oxide can be a useful tool in helping patients
who desire a less-medicated birth
• Nitrous can also provide pain relief for bedside
procedures requiring analgesia or anxiolysis
• Documenting safety/outcomes is important
11/7/2016

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QUESTIONS?

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• AHRQ (2011). Evidence-based practice center systematic review protocol. Project title: Nitrous oxide for the management of labor pain. Retrieved
from http://effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?productid=675&pageaction=displayproduct
• American College of Nurse-Midwives. (2010). From the American College of Nurse-Midwives: Nitrous oxide for labor analgesia. Journal of
Midwifery & Women’s Health, 55(3), 292– 296
• Collins, M. (2015). A case report on the anxiolytic properties of nitrous oxide during labor. Journal Of Obstetric, Gynecologic, & Neonatal Nursing:
Clinical Scholarship For The Care Of Women, Childbearing Families, & Newborns, 44(1), 87-92. doi:10.1111/1552-6909.12522
• Khadem, N., Zirak, N., Soltani, G., Sahebdelfar, N., Sepehri Shamloo, A., & Ebrahimzadeh, S. (2013). Comparison of epidural versus entonox for labor
analgesia in nulliparous women. ‫تروما‬ ‫و‬ ‫جراحی‬ ‫نشریه‬,1(1),1-5 . Retrieved form http://www.ijs.ir/
• King, T., Brucker, M., & Fahey, J. (2013). Varney’s nurse midwifery. Sudbury, MA: Jones and Bartlett Publishing.
• Klomp T, van Poppel M, Jones L, Lazet J, Di Nisio M, Lagro-Janssen ALM (2012). Inhaled
• analgesia for relieving pain during labour. Cochrane Reviews.
• Lederman, R. P., Lederman, E., & McCann, D. S. (1985). Anxiety and epinephrine in multiparous women in labor: relationship to duration of labor
and fetal heart rate pattern. American Journal of Obstetrics and Gynecology, 153(8), 870-877. http://dx.doi.org/10.1016/0002-9378(85)90692-1
• Levinson, G., & Shnider, S. M. (1979). Catecholamines: The effects of maternal fear and its treatment on uterine function and circulation. Birth, 6(3),
167-174. http://dx.doi.org/10.1111/j.1523-536x.1979.tb01329.x
• Likis, F. E., Andrews, J. C., Collins, M. R., Lewis, R. M., Seroogy, J. J., Starr, S. A., ... & McPheeters, M. L. (2014). Nitrous oxide for the management of
labor pain: a systematic review. Anesthesia & Analgesia, 118(1), 153-167. http://dx.doi.org/10
• Lindholm, A., & Hildingsson, I. (2015). Women's preferences and received pain relief in childbirth–A prospective longitudinal study in a northern
region of Sweden. Sexual & Reproductive Healthcare, 6(2), 74-81. http://dx.doi.org/10.1016/j.srhc.2014.10.001
• Pasha, H., Basirat, Z., Hajahmadi, M., Bakhtiari, A., Faramarzi, M., & Salmalian, H. (2012). Maternal expectations and experiences of labor analgesia
with nitrous oxide. Iranian Red Crescent Medical Journal, 14(12), 792. http://dx.doi.org/10.5812/ircmj.3470
• Pita, C., Pazmiño, S., Vallejo, M., Salazar-Pousada, D., Hidalgo, L., Pérez-López, F., & Chedraui, P. (2012). Inhaled intrapartum analgesia using a 50-50
% mixture of nitrous oxide-oxygen in a low-income hospital setting. Archives Of Gynecology & Obstetrics, 286(3), 627-631. doi:10.1007/s00404-
012-2359-6
• Posner, G., Black, A., Jone, G., & Dy, J. (2013). Oxorn-Foote Human Labor & Birth. (6th Ed.) New York, NY: McGraw Hill.
• Rosen, M. (2000). Nitrous oxide for relief of labor pain: A systematic review. American Journal of Obstetrics and Gynecology. 186, 110-26
• Rosenstein, M., Flood, P., Thiet, M. P., Nakagawa, S., Bishop, J., & Cheng, Y. (2014). 598: The use of nitrous oxide analgesia during labor at a single
institution in the United States. American Journal of Obstetrics and Gynecology, 1(210), S294-S295. http://dx.doi.org/10.1016/j.ajog.2013.10.631
• Rooks, J. P. (2007, May). Use of Nitrous Oxide in Midwifery Practice–Complementary, Synergistic, and Needed in the United States. Journal of
Midwifery & Women's Health. pp. 186-189. http://dx.doi.org/10.1016/j.jmwh.2007.02.017.1097/01.aoa.0000455280.655.3
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References

28. Sandy.Hoffman@allina.com
Debbie.Biffle.@allina.com
thank you!