Nitrous Oxide Makes a Comeback
By Jessica Pasley
In 2014 Nicole Dutcher delivered her first child using natural childbirth. She was passionate about trying it again with her second pregnancy. But one thing stood in the way — her memory. “The reality of the intensity of natural childbirth with no pain relief really stuck with me,” Dutcher said. “I had a bit of unexpected fear going into my second delivery, and that anticipation became a real challenge. I had an open conversation about my fears and concerns going into my second birthing experience with my midwife, and I am so thankful I did.”
Dutcher and her husband discussed using nitrous oxide as a noninvasive option for pain relief.
As a burn unit nurse at Vanderbilt University Medical Center, Dutcher was familiar with nitrous oxide as an inhaled analgesic to reduce pain during various procedures. “The fact that I would be in control of the administration of the nitrous was really what enticed me,” she said. “The ability to use nitrous during the entire process is a huge advancement. Just knowing that the option was available gave me peace of mind that I did not have otherwise.
“It did not completely take away my pain, but it took the edge off. It eased the intensity and it allowed me to feel the movement and transition in childbirth, which was very important to me.”
Michelle Collins, Ph.D., CNM, FACNM, FAAN, couldn’t be more pleased with Dutcher’s assessment of her childbirth experience with nitrous oxide, also known as laughing gas. It’s the reason she advocated to introduce nitrous oxide to Vanderbilt University Adult Hospital’s labor and delivery unit five years ago.
Since then, a growing number of women at Vanderbilt and around the country are opting to use the analgesic, which is making a comeback in the labor and birth field after a nearly 50-year hiatus. Because nitrous does not affect fetuses in the same way that other pain reliever methods do, it is considered a safe option for labor and birth.
“I first saw it while I was in London during my undergraduate nursing program,” said Collins, professor of Nursing and director of the Nurse-Midwifery specialty program at Vanderbilt University School of Nursing (VUSN). “I spent a semester there and it really impacted me. It was my first introduction to both midwives and nitrous oxide, which turned out to be pivotal for my career.
“While working as a labor and delivery nurse in the U.S., I never saw nitrous used and it struck me: Why don’t we have this option in the U.S.?”
It wasn’t until Collins joined Vanderbilt that she decided to follow up on her desire to introduce another option for laboring mothers. Her most important task was beginning dialogue with members from each service area aligned with labor and delivery — newborn nursery, neonatal intensive care, nursing management, risk management, obstetrics, midwifery, anesthesiology, maternal-fetal medicine and more. Collins and her team were committed to ensuring that policies, procedures and education were in place to make the option a reality.
It took two years and she hasn’t looked back.
“This is a passion of mine and it’s exciting to see the growth in five years,” she said. “It’s thrilling that we have been able to impact this kind of change across the country.
“When Vanderbilt first offered nitrous oxide in 2011, there was only one other medical center in the U.S. actively using nitrous,” Collins said. “Now more than 300 hospitals and 70 birthing centers in the U.S. use it as a tool for pain management. When you consider how many birthing sites there are in the country, that may not sound like a lot, but when you think about how long it takes for change to occur in practice — it really has come a long way in five years.”
Nitrous oxide is not new to the labor and birth environment worldwide. Known as “gas and air” in Europe, the United Kingdom and Canada, nitrous is used by more than half of all laboring women in those countries. Usage rates are as high as 85 percent in some countries.
In the U.S., it was commonly used before regional anesthesia grew in popularity in the 1940s. As these techniques advanced and epidural use was introduced, nitrous oxide in the U.S. was nearly eliminated.
“If you look at it purely from the perspective of pain relief, an epidural is more effective, but not everyone wants, nor is everyone an appropriate candidate for, regional anesthesia,” Collins said. “We believe that women should have access to all safe alternatives in labor and birth — whether that is a nonmedicated birth, nitrous oxide or an epidural. For us, it is about empowering women to make the best informed choices.”
The response to nitrous oxide availability at Vanderbilt has been fulfilling for Collins.
Nitrous oxide is safe, simple to use, self-administered by the laboring mother and inhaled through a handheld face mask. Collins said there are many reasons nitrous oxide is attractive to moms and health care providers: control over pain relief, anxiety-decreasing effect, disassociation from pain, no residual effects, ability to maintain mobility, no time constraints on use, can be used at any stage of labor, ability to transition to other pain relief options if necessary and multiple use for laceration repair or IV/epidural placement. On top of all that, it is patient-controlled.
“There is really good literature on what leaves a woman satisfied with her labor and birth experience,” Collins said. “The two most important factors are the relationship she has with her provider and the degree of empowerment or involvement she feels she has in the decisions made during the course of her labor and birth.”
Shauna Zurawski’s birthing experience has run the gamut from an epidural-assisted first birth, to an unmedicated childbirth with her second child and now nitrous oxide use for her last two.
Although hesitant at first to use the gas, she is now a big proponent.
The day she decided to give nitrous oxide a try, Zurawski’s labor was not progressing and exhaustion was setting in.
“I took my first deep breath (of nitrous) and was instantly relaxed so much that I fell asleep,” Zurawski recalled. “I rested and my contractions began to pick up. I stopped fighting the labor. The nitrous actually helped me to relax, breathe and get rid of the fears and anxieties that were building up.
“I was amazed. It turned something I thought was going to be extremely hard into something beautiful.”
During Zurawski’s most recent birth, the nitrous oxide had been ordered and was ready for her when she entered her birthing suite.
“Labor and delivery is such a huge and special experience. You have so many expectations for it already and you want everything to go well. The nitrous helps me distance myself from the pain,” she said. “I was aware of the pain, but this took the edge off and allowed me to be present and enjoy the birthing experience.”
At Vanderbilt, nurse-midwives or physicians caring for the laboring mother order the nitrous oxide, while anesthesiologists must initiate or turn it on for each patient. Upon admission, every mother receives an anesthesia consult to go over the various options available for pain relief. If nitrous oxide is a route chosen by the patient, she and her family are given very specific instructions on its use and she is free to switch to a different method of pain relief at any time.
Vanderbilt has three portable nitrous delivery apparati (systems) that can be used in any of its labor and delivery suites. The portable device allows laboring mothers to move around their rooms.
Only one dosing concentration is used in the birthing scenario — a 50/50 mix of nitrous oxide and oxygen. Nitrous is delivered through a mask, which must be held by the patient. As the patient inhales through the mask, a special valve called a demand valve opens to allow the odorless, tasteless gas to come through. The patient then exhales into the mask, which closes the demand valve, cutting off the flow of nitrous oxide. An apparatus inside the mask scavenges the exhaled gas and deposits it into a waste tank in the wall. This limits the gas exposure of others in the room.
“It is very important that the patient holds the mask herself and administers the nitrous,” Collins said. “No one else is allowed to hold the mask for her. When she has had enough, she will not be able to bring the mask to her face. This prevents any chance of inhaling too much nitrous oxide and is a built-in safety mechanism of this modality.
“It contributes to what makes this so attractive to both moms and providers.”
Vanderbilt sees about 350-360 deliveries a month. Data compiled by the obstetrics department indicates that nitrous is selected by 14.6 percent of patients (the figures are higher — nearly 22 percent — for patients attended by School of Nursing nurse-midwives). The same data shows that about 30 percent of patients later transition to epidural.
Department of Anesthesiology records show continual interest in nitrous use since its introduction in 2011.
“Our goal is to offer patients a choice,” said Curtis Baysinger, M.D., professor of Anesthesiology, OB division. “My interest is in the women who labor here and deliver here, and to make sure that Vanderbilt has a wide range of choices of the type of environment in which they want to labor as well as an array of choices of analgesia that we can safely provide.
“In many instances, nitrous helps women get through labor or allows them to delay the use of an epidural.”
While nitrous oxide wasn’t new to the Medical Center — it had been used in operating rooms and by the Department of Oral and Maxillofacial Surgery — its use further expanded in 2014. Now areas like the burn unit and Monroe Carell Jr. Children’s Hospital at Vanderbilt (for help with IV sticks and radiology procedures) employ it to provide much needed comfort as an alternative to other pain relief measures, said Christopher Hughes, M.D., associate professor of Anesthesiology and chair of the VUMC Sedation Committee.
“We do have guidelines, or safety parameters, detailing which (nonobstetric) patients are candidates for nitrous,” he said. It’s not suitable for those with severe lung disease, increased intracranial pressure, impaired levels of consciousness or intoxication, nor for patients with other medical issues like intestinal obstruction or recent ocular surgeries.
“As an inhaled anesthetic, it is absorbed through the lungs,” Hughes said. “What is appealing to people is that it works quickly — fast onset and fast offset. And it’s not dependent on other organs for elimination from the body.”
Nitrous is a good option for mothers who are not candidates for other forms of pain relief. It is this group of women that tugged at the heart of labor and delivery nurse Michelle Amstutz.
As a bedside nurse at St. Joseph Ann Arbor in Michigan, Amstutz had witnessed many women experience childbirth with no safe options for pain relief. It was during a national Association of Women’s Health, Obstetric and Neonatal Nurses (AWHONN) conference that she heard Collins’ presentation on nitrous oxide use in childbirth.
“I had no idea it was making a comeback and was available for use,” she said. “I’ve been in labor and delivery for 20 years, and as a nurse it doesn’t feel good not being able to offer some comfort to your patient.”
Amstutz approached Collins with her idea of starting a program in Ann Arbor. Collins was happy to share research, ideas, strategies and first-hand experience. The two corresponded back and forth, then Amstutz worked on implementing the use of nitrous oxide for laboring women at her hospital.
With Amstutz as advocate, St. Joseph launched a nitrous oxide program in October 2015. “It took me two years to get the program in place and we have had a great response,” she said. “It has been so empowering for our nurses to do this for our patients.”
Since the use of nitrous oxide in the U.S. for labor pain is a relatively new occurrence, evidence-based research on the analgesic is still limited but growing. Collins said that she knows of several studies currently underway, including some at Vanderbilt. She and Jeremy Neal, Ph.D., CNM, R.N., assistant professor at the School of Nursing, are working on a study involving the creation of a national data repository. “Currently, there is not an existing national database where data regarding women who use nitrous oxide for labor and birth is registered,” she said. “We are really on the cusp of widespread use of this new — yet old — modality, and the need to collect data in many areas regarding its use in labor and birth is paramount.”