Surprisingly, a common anesthesia drug called desflurane is also a climate super-pollutant. In fact, in terms of its impact on warming the planet, the gas is several thousand times more potent than carbon dioxide.
Starting Jan. 1, the European Union banned its use except when medically necessary. To better understand this, The World spoke with Jodi Sherman, an anesthesiologist who directs Yale’s program on healthcare environmental sustainability.
She says one of the issues with all inhaled anesthetics is how medical facilities dispose of them. After these gases are used, Sherman said, they are vented into the atmosphere, where they can remain for one to ten years. Their impact depends not only on heat-trapping capacity but also on potency, she said, noting that desflurane is less potent and therefore used in larger amounts, increasing its overall impact.
Carolyn Beeler: So these are drugs that patients inhale when they’re in surgery or something like that. And so, when or why are they vented? Is that just that most of them actually go unused and have to be kind of disposed of into the air?
Jodi Sherman:No, that’s a great question. So our body doesn’t really metabolize them, maybe a tiny bit in the case of sevoflurane, but essentially, as you’re breathing them, they do what we intend them to do, and they make you unaware and not feel pain while you’re in induced sleep. But when you’re done breathing them, they just get vented off the rooftop.
So we breathe them in, and they do their job, and then we basically just breathe them back out?
That’s correct. And we need to protect indoor staff so that they don’t fall asleep during surgery. So they’re essentially sucked out. That is very important. So they’re sucked out and vented from the facility. Now, there is some technology that exists to try to capture those gases for potential reuse or at least for storage. But their efficiency rates are really quite low. So they’re not really a viable solution.
So, how commonly used right now is Desflurane, and why would you use it as opposed to any of the other alternatives that might be available?
Well, there are three common volatile anesthetics, which is the class of drug that desflurane is in common use. In some parts of the world, there’s a fourth medication that’s fallen out of favor because it’s toxic to the liver, and that’s halothane, but it is still common in low-resource settings, and that is being phased out. And so they all functionally do the same thing, but they have slightly different properties, and different properties, including how fast you fall asleep and wake up. And how potent they are. So how much drug do you need to, or how much volume or mass of the medication do you need to have the same clinical effect?
So how hard is it for anesthesiologists, especially those, for example, in Europe, where desk flooring is largely banned, how hard it is to replace it with a different drug of its class?
Oh, it’s super easy. We have other medications that we give all the time through intravenous routes. We give phenylephrine, ephedrine, and epinephrine drugs you’ve probably heard of before. So, there is nothing about desflurane’s rank clinically that makes it so unique that we need to keep it.
So this feels like a little bit of low-hanging fruit if we’re thinking about the climate impact of, for example, hospitals. Is that fair?
It’s a very low-hanging fruit, and for multiple reasons, including that the drug is much more expensive than the other drugs. So we substituted ceboflurine for deserine at Yale New Haven Health System back in 2013 and estimated that simple substitution saved our organization $1.2 million just in drug procurement costs alone. But it’s also important to know that all the inhaled anesthetics [are] our greenhouse gases, but desflurane is definitely a low-hanging fruit.
Do you know what the projected environmental greenhouse gas savings would be if all of Europe banned desflurane except in medically necessary cases?
Unfortunately, I don’t know. It depends on what they’ve already been purchasing or purchasing in the most recent years. Because essentially, everything you buy just gets used and just tossed in the environment. So we need to know how much is being procured. I can tell you, desflurane has been falling out of favor for well over a decade now. There’s just been a lot of traction and interest in healthcare overall, and particularly in our specialty, around concerns about environmental contamination from the healthcare industry and what can be done about it. There has been action throughout the US and Europe in particular, and now across Canada and other parts of the world and Asia; the popularity of the medication has declined globally because of this concern.
Yeah, I did want to talk about the bigger picture of the health care industry trying to reduce its climate impact. I was reading that the emissions from just dust fluorine have a climate impact equivalent to the greenhouse gas emissions from approximately 1.5 million automobiles. So that is not nothing. It is also not a huge portion of the world’s greenhouse gasses. So let’s talk bigger picture a little bit. What else is the healthcare industry doing to try to reduce its carbon footprint or greenhouse gas footprint?
Well, let’s take a step back. That number might sound trivial, but if you start delving into the health care system, it’s actually a bigger number. So there is data to suggest that the footprint of a hospital, about 5% of that is coming just from inhaled anesthetics. Now, if you take a step further into perioperative services, surgical services, about half the footprint in the operating room is coming just from inhaled anesthetics. So if you could knock that down.
There’s a huge opportunity there. And across the healthcare system, not just in the operating room or for anesthesia, how big of a priority is it to cut greenhouse gas emissions? Is this something your field is really starting to try to tackle?
Well, there is a lot of global interest in this space right now. Much of this is driven by health professionals and their concerns. We understand, both professionally and personally, that we are causing harm when we take care of patients, which is against our mission. So the movement is really coming from the ground up through the health professionals. Where we really need help is in strengthening regulations. Because there’s only so much agency you have as a health professional. We really need to change our organizations to try to drive more sustainable actions. So it really requires a whole government approach. We need regulations to drive accountability.
Parts of this interview have been lightly edited for length and clarity.
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