More on Project SPRUCE (Saving our Planet by RedUcing Carbon Emissions)

Myron Yaster MD

Remember the movie Blade Runner?  Maybe, maybe not. Air so dense and polluted you couldn’t see the sky.  Possible? Alarmist? Maybe, maybe not.  When I moved to Colorado, I was told that the skies were brilliantly blue, cloudless and sunny 300+ days a year.  And then the California and Western wildfires darkened the sky for months.  When I would speak to my family and friends back East, it was hard for them to believe.  “How could fires hundreds and thousands of miles away darken your skies?” Then this hit them a few weeks ago.

Regular readers of the PAAD know that the Society for Pediatric Anesthesia’s (from the website) has a “Special Interest Group for Sustainability that brings together pediatric anesthesiologists with a passion for learning, teaching, and practicing ways to reduce the environmental impact of anesthesia and the wider operating room environment. The SIG will facilitate education on sustainability topics at meetings, foster collaboration across institutions, promote sharing of ideas for projects and publications, and maintain the creative energy of pediatric anesthesiologists working for changes in their hospitals.  Further, the Sustainability SIG is helping to recruit pediatric anesthesia groups to a multi-institutional quality improvement and implementation science project to reduce GHG emissions! Visit the website to learn more!  Project Spruce Forest”  Today’s PAAD is a paper published by Hansen et al.¹ detailing Project SPRUCE.  All of SPA’s committees and special interest groups are open to all of the members to join and participate. Don’t put this off and join the Sustainability SIG today.  Simply contact Diane Gordon, Liz Hansen, Carole Lin, or Galaxi Li. Myron Yaster MD

Original article

Elizabeth E Hansen, Jennifer L Chiem, Kimberly Righter-Foss, Yuanting Zha, Hannah C Cockrell, Sarah L M Greenberg, Daniel K Low, Lynn D Martin.  Project SPRUCE: Saving Our Planet by Reducing Carbon Emissions, a Pediatric Anesthesia Sustainability Quality Improvement Initiative.  Anesth Analg. 2023 Jul 1;137(1):98-107. PMID: 37145976

The climate emergency is a health crisis that disproportionately impacts children and other vulnerable populations. The planet is warming due to human activity and “healthcare “produces 2 gigatons of carbon dioxide equivalents (CO2e) per year, 4.4% of global net emissions.”¹ Inhaled anesthetics including desflurane, isoflurane, sevoflurane, and nitrous oxide are potent greenhouse gases (GHGs).  As discussed in previous PAADs, desflurane is the worst and has nearly 50 times the greenhouse gas emissions than other anesthetic agents when used clinically. With safe and effective alternatives to desflurane, continuing its use is difficult to defend. Many hospitals have decreased its use, and others have removed it from formulary. Nitrous oxide is also a problem.  Its “114-year atmospheric lifetime and ozone-depleting properties result in significant global warming effects.”^{1, 2}

“Project SPRUCE (Saving our Planet by RedUcing Carbon Emissions) was launched at Seattle Children’s Hospital (SCH) and its ambulatory surgery center (ASC) to produce a 50% reduction in the carbon emissions associated with anesthesia gasses in the ORs by end of June 2022. Aims of this report were to: (1) review strategies for reducing emissions from inhaled anesthetic agents; (2) outline the series of interventions, including education, protocol changes, and practice constraints; and (3) highlight the results and impact of real-world data to drive and sustain change.”¹

What did they do? They eliminated desflurane vaporizers from their anesthesia machines, utilized low fresh gas flows with decision support and low-flow education, avoided or limited nitrous oxide, monitored and reported emissions in real time using AdaptX software (www.adaptx.com, Seattle WA).

OK, how did they do? Over a five year period they were able to reduce measured GHG emissions from inhaled anesthetic agents by 86%.¹ Wow!  One of the most surprising findings to me was that a large amount of nitrous oxide waste came from “significant leaks that occur from central supply nitrous oxide tanks. As reported elsewhere, this can account for over 90% of emissions from nitrous oxide.”^{1, 3}  Although Hansen et al. do not explicitly suggest this, I’m wondering if we should abandon central nitrous oxide in our hospitals and switch back to E cylinders attached to our anesthesia machines?

Lots of food for thought.  Let me know your thoughts and I will post in a Friday Reader response.  One final thought for you to consider: Project Spruce is now conducting multi-institutional studies.  If you and your department are interested in joining please contact Liz.

References

1.           Hansen EE, Chiem JL, Righter-Foss K, et al. Project SPRUCE: Saving Our Planet by Reducing Carbon Emissions, a Pediatric Anesthesia Sustainability Quality Improvement Initiative. Anesthesia and analgesia. Jul 1 2023;137(1):98-107. doi:10.1213/ane.0000000000006421

2.           Varughese S, Ahmed R. Environmental and Occupational Considerations of Anesthesia: A Narrative Review and Update. Anesthesia and analgesia. Oct 1 2021;133(4):826-835. doi:10.1213/ane.0000000000005504

3.           Seglenieks R, Wong A, Pearson F, McGain F. Discrepancy between procurement and clinical use of nitrous oxide: waste not, want not. British journal of anaesthesia. Jan 2022;128(1):e32-e34. doi:10.1016/j.bja.2021.10.021