Episode #246 Ditching Nitrous Oxide: The Bike Commuter’s Guide to Safe and Sustainable Anesthesia

Hello and welcome back to the Anesthesia Patient Safety Podcast. My name is Alli Bechtel, and I am your host. Thank you for joining us for another show. We have an exciting interview series that we are kicking off today all about safe and sustainable pediatric anesthesia care. We talk about the scope of the problem and what anesthesia professionals can do to make sustainable and safe anesthesia care part of their practice for all patients. Our guest on the show today is Dr. Liz Hansen. So, stay tuned for our conversation about this important topic.

Before we dive further into the episode today, we’d like to recognize Draeger Medical, a major corporate supporter of APSF. Draeger Medical has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Draeger Medical –we wouldn’t be able to do all that we do without you!”

And now, my conversation with Dr. Liz Hansen.

[Bechtel] “Can you introduce yourself? Tell us about your anesthesia training, career, and current role?”

[Hansen] Hi! I’m Liz Hansen, a pediatric anesthesiologist at Seattle Children’s Hospital, and an associate professor of anesthesiology and pain medicine at the University of Washington. I graduated from the medical scientist training program at Washington university in St. Louis, then did my residency training at UW and stayed on at Seattle Children’s for my pediatric anesthesia fellowship.

[Bechtel] What got you interested in pediatric anesthesia and sustainability? (personal story or de-identified patient story?)

[Hansen] Starting out in medical school, I knew I wanted to work with kids. I thought I’d become a pediatric infectious disease specialist like my undergraduate research mentor. Once I got into the clinical rotations though, I realized I just loved the operating room setting, doing procedures and working at a faster pace. I then got a chance to do a pediatric anesthesia rotation, and the decision was made! It’s the best job – I get to play games with my patients, help to take away their pain, and guide them through a stressful and scary experience, all while working with the best team of surgeons, nurses, techs and anesthesia colleagues.

My interest in sustainability has been life-long – I have always been a recycling champion, bike-commuter and environmentalist. The connection to anesthesiology began when I started as an attending nearly 8 years ago. I had the chance to meet with our sustainability manager, Colleen Groll, to discuss the hospital’s greenhouse gas inventory. She performed this inventory as part of the hospital’s commitment to sustainability. As you know, delivery of healthcare causes unnecessary pollution and contributes to the problems of global warming and a less healthy planet for our patients. This poses an existential threat to the health and lives of people all over the world. In June 2022, Seattle Children’s commitment to sustainability strengthened with the signing of the HHS Health Care Sector Pledge. Our CEO – Dr. Jeff Sperring – committed to reducing the organization’s emissions and achieving carbon neutrality by 2025 – this year!

Colleen showed me the data for anesthesia gases based on our annual purchasing of these agents. I was shocked to learn that 7% of our total hospital’s emissions were from the gases I was using every day to care for my patients. She also introduced me to some tools and resources that showed how to deliver lower-emissions anesthetics to our patients without compromising safely.

[Bechtel] Can you tell us more about your work with eliminating the use of nitrous oxide? How did you get started on this project? What have you learned along the way?

[Hansen] When I was in training, the dogma was that any patient getting an inhalation induction, except little babies, should get 50% nitrous oxide with sevoflurane. I was also taught to use high flow nitrous oxide for teenagers during IV placement. But then I did the math, using Yale’s Gassing Greener App, and found that even just 5 minutes of nitrous oxide at 50%, at our typical fresh gas flows, was equivalent to driving about 25 miles in a gas-powered car – and that is just for a few minutes for one patient! I was biking to work and avoiding driving my car, but then at work I had a massive carbon footprint! So, I phased nitrous out of my routine practice, and realized I could still provide my patients with a really smooth experience. I had to modify my technique a little bit, with more mask preparation, coaching and distraction, but I got pretty good at it rather quickly. I am also lucky enough to work with a team of talented CRNAs who were game to try without nitrous as well, and I could see their skills grow as we learned how to do this together. A few more colleagues joined our nitrous-free cohort, and we educated our group over the next year. Now, our group uses nitrous oxide for fewer than 1% of our patients, and our outcomes remain excellent. We have very high family satisfaction scores, and all our other balancing measures have remained the same or improved though other QI work.

[Bechtel] Don’t worry to our listeners, I will include the information about all the apps and resources that we talk about on the show today in the show notes. Can you tell us more about mask acceptance and the use of Child Life?

[Hansen] I cannot sing the praises of child life specialists enough! They are amazing, caring individuals who make such a difference for our patients! I work closely with our Child Life team and began talking with them about our efforts to reduce emissions, including our transition away from nitrous oxide. They invited me to give a presentation about sustainability in anesthesia and were completely on board to support our efforts in emissions reduction!

When I have a patient who might be nervous about anesthesia, and especially mask induction, I try to involve our CLS early on. They help with introducing the mask to the child, offer scents to paint inside, and stickers for decoration of the mask. They will help the child practice breathing through the mask even before we arrive at the operating room. They will partner with families to meet the child where they are and help provide appropriate distraction as well. They’ve shown me several smartphone or tablet-based apps and videos that seem to work particularly well for patients who need some distraction.

Another technique we have learned as we do nitrous free mask inductions is coupled with another lower emissions tactic – low fresh gas flows. I typically start oxygen only at about 3 LPM and get the child used to the feeling of breathing through the mask, before introducing any gas. The flow is low enough that it’s not a blast of air up their nose, and they can take a moment to get used to it without you worrying that if they move away, everyone else in the room is breathing their sevoflurane. Then, once they are used to the mask with oxygen alone, we turn the sevo vaporizer on (while using our handy distraction methods). I often coach older kids to breathe through their mouth at this point, so the smell is less noticeable.

For kids that can cooperate with a vital capacity breath, I offer the option of a faster induction with a primed circuit. We practice the deep breaths with the mask only, and then when they are ready, connect the hose to the mask. Some of the older kids do really well with this method and are asleep within 2-3 breaths.

[Bechtel] How can anesthesia professionals get started for making these changes in their department? What have you learned along the way?

[Hansen] For many of my peers and patients, the issue of climate change is daunting. Never mind confronting the fact that while working to care for our community on a daily basis, we now know we are contributing significantly to global warming. But, as one of my colleagues likes to share, the antidote to despair is action! And there are reasons to be optimistic! Anesthesiologists, in particular, have the potential to have a major impact on the environmental footprint of a hospital!

If you are still using nitrous oxide, I encourage you to try a nitrous free induction on your next patient. You can start with a cooperative child who is likely to accept the mask well and then move into more challenging cases. Try out some of the apps on your phone or tablet for distraction. Spend an extra minute with your patient to prepare them for the mask.

Other simple but impactful practice changes include turning off the fresh gas flow, not the vaporizer, when performing airway management like intubation

You can use low fresh gas flows, even with sevoflurane, as modern CO2 absorbers do not cause compound A creation. The ASA now has a statement in favor of low flow. If you want to learn more about low flow, I recommend the APSF course on low flow anesthesia.

https://www.apsf.org/apsf-technology-education-initiative/low-flow-anesthesia/

Avoid desflurane along with nitrous oxide as they are both very potent greenhouse gases, and nitrous oxide depletes the ozone layer

On a departmental level, folks can identify a sustainability champion to lead their group. We have found that education and socialization, along with practice constraints and data feedback, have allowed us to reduce the environmental footprint of inhaled anesthetics by over 90%. This requires leadership support, ongoing educational efforts for new hires and rotating trainees, and some method for data collection. We use a software solution developed by my colleague, Dan Low, called AdaptX. Using this software we can easily track our emissions, identify the folks with the lowest emissions to serve as role models and educators, and pinpoint the areas to focus on next, along with monitoring our balancing measures.

[Bechtel] Can you tell us more about your work with sustainability? How can anesthesia professionals practice more sustainable anesthesia, especially with pediatric anesthesia? Why are you so passionate about sustainability?

[Hansen] Along with the gas related emissions reduction work we are doing in the ORs, I chair the perioperative green team and support that team in waste reduction, recycling and other sustainability efforts. Our team participates in the annual drawdown eco-challenge (coming up soon!) to encourage folks to think about sustainability in their daily lives.

https://drawdown.ecochallenge.org/

When we published our emissions reduction work, it garnered a lot of interest around the world. We were able to start an international consortium of anesthesia groups interested in working together to reduce emissions, called Project SPRUCE (Saving our Planet by Reducing Carbon Emissions). My co-PI, Dr. Diane Gordon, is an internationally recognized leader in sustainability and the chairperson of the Society for Pediatric Anesthesia Special Interest group in Sustainability. We are mentored by past SPA president Dr. Lynn Martin. The founding members of this consortium have already achieved their first goal of reducing emissions by 50% within a year and are now working on additional reductions.

[Bechtel] Is sustainable anesthesia compatible with safe anesthesia? How can anesthesia professionals provide safe and sustainable anesthesia?

[Hansen] Sustainable anesthesia is absolutely safe! Our consortium has shown that outcomes are the same or better with lower emissions anesthesia. Use of low flow anesthesia is safe with modern CO2 absorbents and vigilant attention to volatile concentration and FiO2. Avoiding nitrous oxide during induction allows for higher FiO2 and better preoxygenation.  Use of propofol based TIVA is both lower emissions and associated with improved outcomes like reduced emergence delirium, lower rates of PONV, and fewer respiratory complications.

[Bechtel] What do you hope to see going forward when it comes to sustainable and safe pediatric anesthesia care?

[Hansen] I hope that sustainable methods for anesthesia become the default in pediatric anesthesia practices!

We should track emissions as a quality metric; while monitoring balancing measures to ensure we continue to provide safe and effective care.

[Bechtel] What’s next for your research or projects?

[Hansen] Project SPRUCE has grown and continues to recruit new members. Folks are really eager to work on sustainability in healthcare and want to maximize their impact through collaboration. We continue to work together on reducing emissions and are planning to publish our first round of results this year.

At the local level, I’m working with my hospital to reduce nitrous oxide waste in our centrally piped supply. We are moving to portable tanks that can be closed between users, which would allow us to reduce nitrous oxide waste by over 90%. Most hospitals and surgery centers with centrally piped supplies of nitrous oxide have enormous inefficiencies such as the gas leaks from manifolds, tank pressure release valves, pipe fittings and connections.

[Bechtel] Is there anything else that you want to share that we have not talked about already?

[Hansen] Lead by example – as a physician you are already a leader. Patients and colleagues listen to you, especially if you lead with knowledge, clarity and passion. Your individual actions and choices do matter, especially working in healthcare, and when you are able to influence others. Physicians and hospitals must lead the way. Anesthesiologists have always been leaders in patient safety, and now we must lead in greening the OR to combat the climate crisis.

[Bechtel] Thank you so much to Dr. Liz Hansen for joining us on the show today.

If you have any questions or comments from today’s show, please email us at [email protected]. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.

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Until next time, stay vigilant so that no one shall be harmed by anesthesia care.

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