Wildfire smoke and adverse respiratory perioperative events
Myron Yaster MD and Lynne G. Maxwell MD
When I moved to Colorado, I was told the summers are hot, the winters are very cold and snowy, and the sky is crystal clear and blue for most of the year. Like many other things I was told before moving here this just isn’t true. The blue cloudless skies may have been true in the past, but climate change and the large number and extensive wildfires in the west have changed the West’s air quality significantly. Coming from the East the effects of these fires and drought are nothing short of astonishing. The idea that fires in California or Canada or Colorado or New Mexico could darken the skies hundreds or even thousands of miles away was simply inconceivable to me. And these fires are not one and dones…the number of wildfires per year has nearly doubled in just a decade. Not only has the number of fires increased but so has their extent and severity. Climate change, extreme heat and resultant drought combine to amplify the conditions that enable and create wildfires.
As anesthesiologists we contribute to the climate catastrophe on a daily basis. Just think of all of the waste we generate in the ORs from our disposables to our anesthetic gases that are greenhouse gases (desfluranej) which have more global warming potential than carbon dioxide. The Society for Pediatric Anesthesia has a Sustainability Special Interest Group led by Dr. Diane Gordon and the new Project Spruce Forest led by Drs. Elizabeth Hansen, Lynn Martin, and Diane Gordon that I would encourage you to investigate and join.
SIG contact link:
https://pedsanesthesia.org/contact-sustainability-sig/
PRoject SPRUCE Forest:
https://sites.google.com/view/spruceforest/resources?authuser=0.
As you will discover in today’s PAAD, these wildfires contribute to poor air quality and result in perioperative respiratory events like laryngospasm, bronchospasm, and hypoxemia in patients with asthma or who were born prematurely and are much akin to anesthetizing a child with an acute URI, or those patients exposed to tobacco smoke in the home. Thus, just like considering canceling or deferring surgery in a child because of an acute URI, air quality measures may also need to be factored into your decision making. Myron Yaster MD
Original article
Marsh, B. , Kolodzie, K. , Robinowitz, D., Jacobson, A., Ferschl, M. (2022). Wildfire Smoke Exposure Is Associated with Adverse Respiratory Events under General Anesthesia in At-risk Pediatric Patients. Anesthesiology, 137 (5), 543-554. doi: 10.1097/ALN.0000000000004344. PMID: 35950818
Editorial
von Ungern-Sternberg, B. & Grigg, J. (2022). If We Destroy Nature – We Destroy Ourselves. Anesthesiology, 137 (5), 524-525. doi: 10.1097/ALN.0000000000004393. PMID: 36264091
“Wildfire smoke causes air pollution and severely impacts both the environment and human health. Smoke contains many detrimental compounds, including the gaseous compounds ozone, carbon monoxide, and nitrous and sulfur-containing oxides, as well as particulate matter. Three classes of pollutants generated by wildfires are of particular concern for human health: (1) larger particulate matter represents inhalable particles with an aerodynamic diameter 10 μm or less; (2) fine particulate matter represents inhalable particles with an aerodynamic diameter 2.5 μm or less, and (3) the gaseous compound ozone. For each of these pollutants, an air quality index value of greater than 100 defines unhealthy air quality for sensitive groups, with increasing air quality index levels affecting all. Elevated air quality index is associated with an inflammatory response and respiratory system dysfunction. Numerous studies have shown the impact of poor air quality on asthma exacerbations, emergency department visits, and hospitalizations in both adult and pediatric patients.”.1, 2
We’ve known for a long time that adverse respiratory effects like laryngospasm, bronchospasm, and oxygen desaturation occur more commonly in anesthetized younger children or children with a history of reactive airway disease, prematurity, the presence of an upper respiratory tract infection, obesity, obstructive sleep apnea, and tobacco smoke exposure in the home.3-6 Those of us who anesthetize patients from low resource countries on surgical missions have seen the same adverse respiratory events in children exposed to wood or coal cooking smoke. Marsh et al.1 “hypothesized that an unhealthy air quality index (greater than 100) due to wildfire smoke would increase the risk of an adverse respiratory event under general anesthesia in the pediatric population.” And not surprisingly, they did!
How should we make use of this finding? Most of the complications like desaturation, laryngospasm, and bronchospasm in this study were minor and easily treated by the anesthesia team. Should we cancel surgery in susceptible patients when the air quality index is greater than or equal to 100? How long after wildfire smoke exposure with poor air quality, does increased airway reactivity persist after the air quality index falls below 100? Just like after resolution of a URI, risk most likely persists (for some unknown period). Should parents and surgeons be told of this increased risk before proceeding? Should patients be pretreated with albuterol and/or corticosteroids prior to the induction of anesthesia? Should the method of general anesthesia be changed to limit adverse respiratory events (e.g, avoidance of tracheal intubation when possible)?
We don’t know but would advise using the same mental algorithms you use when anesthetizing a pediatric patient who presents for surgery with an acute URI. I (MY) like to fall back on the advice of Dr. Peter Davis and his mentor, the late Dr. Ryan Cook, who always liked to point out that context matters. Personal habits and anecdotal experiences and memories of your last disastrous experience are powerful influences that affect your responses to the next crisis. You may minimize the risk of poor air quality until a bad outcome occurs which will change how you approach the next couple of patients who present under the same conditions.
Let us know what you think and we’ll post in a reader response.
References
1. Marsh BJ, Kolodzie K, Robinowitz D, Jacobson A, Ferschl M. Wildfire Smoke Exposure Is Associated with Adverse Respiratory Events under General Anesthesia in At-risk Pediatric Patients. Anesthesiology. Nov 1 2022;137(5):543-554. doi:10.1097/aln.0000000000004344
2. Rice MB, Henderson SB, Lambert AA, et al. Respiratory Impacts of Wildland Fire Smoke: Future Challenges and Policy Opportunities. An Official American Thoracic Society Workshop Report. Ann Am Thorac Soc. Jun 2021;18(6):921-930. doi:10.1513/AnnalsATS.202102-148ST
3. Templeton TW, Sommerfield D, Hii J, Sommerfield A, Matava CT, von Ungern-Sternberg BS. Risk assessment and optimization strategies to reduce perioperative respiratory adverse events in Pediatric Anesthesia-Part 2: Anesthesia-related risk and treatment options. Paediatric anaesthesia. Feb 2022;32(2):217-227. doi:10.1111/pan.14376
4. Regli A, Sommerfield A, von Ungern-Sternberg BS. Anesthetic considerations in children with asthma. Paediatric anaesthesia. Feb 2022;32(2):148-155. doi:10.1111/pan.14373
5. Hii J, Templeton TW, Sommerfield D, Sommerfield A, Matava CT, von Ungern-Sternberg BS. Risk assessment and optimization strategies to reduce perioperative respiratory adverse events in pediatric anesthesia-Part 1 patient and surgical factors. Paediatric anaesthesia. Feb 2022;32(2):209-216. doi:10.1111/pan.14377
6. Skolnick ET, Vomvolakis MA, Buck KA, Mannino SF, Sun LS. Exposure to environmental tobacco smoke and the risk of adverse respiratory events in children receiving general anesthesia. Anesthesiology. May 1998;88(5):1144-53. doi:10.1097/00000542-199805000-00003