u/MetabolicMadness

Hopefully this is the correct spot to post. I am an anesthesiologist, and in our field it has become a hot topic to reduce our environmental impact.

To make it short we have essentially began working to eliminate desflurane which is said to have a much worse gwp100 and has an atmospheric life of 14yrs-ish. Then we have sevoflurane or propofol for anesthetic options.

Often it is said even if used the most efficiently way possible that a sevoflurane based anesthetic is producing about 10x more co2e per hour compared to an intravenous agent propofol. I personally do 60%propofol/40%sevo.

Sevo has the benefit if easier and more reliable monitoring of depth. Propofol has less nausea and coughing.. hence why I use a mixture of

My question though is if sevoflurane has an atmospheric life of 1.2-1.4 years. should GWP100 or even 20 for that matter even be used? Its break down products are not toxic or possessing overly warming potential.

This article by a meterologist calls our fields research into the climate impact of volatile anesthetics into question. Which I must admit intuitively makes sense to me because I have never understood how gwp20 or 100 makes sense for a compound that lasts 1-5% of that time. Similarly i think it’s a field ripe for people to churn out easy publications because they can just use a gwp20 and calculate their sevo use and propofol use and bam there is a publication.

Curious if you think this article makes sense or what they are saying is wrong etc.

https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/epdf/10.1111/anae.16189

Title pretty much sums it up. I keep bearing about and reading about how much better TIVA is compared to Sevo for the environment. Often quoting TIVA as 2-3kg of co2 vs 45-50kg per anesthetic

I guess I am just curious to see people’s opinions on this. My major issue with these studies

1. They often are using gas flows of sevoflurane 2lpm whereas I feel it is pretty clearly okay and safe to use .3-.5 now. Compound A isn’t a real issue. This alone makes a 75-90% reduction.

2. They aren’t account for volatile capture systems in hospitals. Which if incinerated reduces co2 impact by 80% and if recycled for re-use 90%.

This theoretically takes the co2 equivalents from 48 to 7 and then to 1.5.. if you run flows of .4 and capture and incinerate sevo. Making it essentially no different than TIVA.

3. co2 equivalents and 100 year co2 equivalents over estimates sevofluranes harm. Why even talk 100 year equivalents on a compound that generally will leave the atmosphere within 1.5 years. — conversely I think we drastically underestimate the impact of plastic tubing and propofol in the environment by only looking at co2.

Propofol and plastics might make less CO2 equivalents, but when they get in ground water and soils they can last a very long time and cause harm. Most of the plastic in the OR (and anywhere) we “recycle” will just end up being shipped to another country and put in a landfill — or end up floating around in the ocean (which again has it’s own co2 and environmental impact).

In some ways I would almost rather have sevo in the air and break down in 1.5 years to nothing than plastic tubes and syringes filling landfills and oceans for hundreds of years to come harming nearby animals

.. I do also sometimes question how much an impact changing the modifiable factors of anesthesia will even make environmentally when you compare our percentage emissions to other industries. I think you could ultimately make a much larger impact by changing other habits like flying less often, less meat, less fast fashion.

Tldr

I guess i am asking anyone away of any studies actually evaluating holistically the life cycle and environmental impact assessment of tiva vs volatile. Further doing so in a modern way (low flow for sure +\- capture)

I’m actually happy to change to tiva but working in a hospital currently that uses capture and running flows of .25 i am just not convinced it’s even better to change?

My partner is looking to do a program that is specifically about thinking about and experimenting with ways to design in the future. In terms of alternative materials, ways to integrate welfare of animals and plants, broadly speaking just eco-modern ideas.

They don’t have an architecture undergraduate. They are contemplating a masters in architecture. Their goal isn’t to become a licensed architect - perhaps to be a designer, working with a company creating interesting design products, starting a design company, working with government to incorporate new ideas.

So they are open to programs anywhere in the world. A bit of an odd question and shot in the dark. Just curious if anyone knows of anything cool.