Use of desflurane dissipates at Good Samaritan

ORs switch to sevoflurane

Anesthesiologists and CRNAs at Good Samaritan have voted overwhelmingly to cease using desflurane, an anesthetic gas proved to contribute exponentially more to the greenhouse gases trapped in our environment than the equally effective and less expensive alternative, sevoflurane.

“We have known for the last several years that no anesthetic gas is really good for the environment, but some are better than others,” said Craig Simmonds, MD, medical director of Perioperative Services and physician champion of the department’s effort to provide more environmentally-conscious care.

“I’m proud we’re taking this significant yet simple step to reduce our footprint, while maintaining the highest standards of care and safety.”

Consider the data:

• Anesthetic gases are estimated to be responsible for up to 0.1 percent of total global carbon dioxide-equivalent emissions contributing to global warming.

• Based on atmospheric sampling of volatile anesthetics, the accumulation of gases is increasing, particularly desflurane.

• In part that’s because it takes 14 years for desflurane to break down in the atmosphere, while sevoflurane breaks down in just one.

• The global warming potential of desflurane, scaled by clinical potency, is approximately 40 to 50 times that of sevoflurane in a 100-year period.

This chart (click on it for a closer look) from 2012 Anesthesia-Analgesia illustrates this comparison with data gathered from the National Health Service in England. The chart also includes isoflurane and nitrous oxide.

True, while the comparison between the two gases is significant, the total contribution to global warming seems small. But consider this:

• The US health sector is responsible for about 10 percent of the nation’s greenhouse gases.

• Five percent of the carbon footprint created by acute-care hospitals is from anesthetic gas.

• Half of all CO2e emissions from perioperative departments are from the use of anesthetic gas.

• The use and selection of inhalational anesthetics is directly within the control of anesthesia practitioners.

“Sadly, if the healthcare sector were classified as a country, we'd be a top emitter globally,” said Chloe Ingoldby, MD, chair of Anesthesia. “Removing desflurane from clinical practice is a large stride forward in reducing our impact while still providing excellent patient care.”

There’s an added benefit, too: cost savings. According to the National Institutes of Health, state societies of anesthesiologists and other agencies, desflurane typically costs more per bottle than sevoflurane. 

• As with all products, costs fluctuate. But currently, a 240ml bottle of desflurane can cost around $148, while a 250ml bottle of sevoflurane costs about $67. 

• The cost per case can be $13.20 for desflurane and $0.63 for sevoflurane. 

Let’s pause for a case study

The campaign to mitigate the impact of anesthetic gases on the environment started more than a decade ago, and the Yale New Haven Health System in Connecticut was an early champion of the effort. In 2013, it eliminated desflurane in favor of sevoflurane.

According to its own data, the resulting annual savings was about $1.2M across the health system, and it generated an estimated reduction of 1,763 tons of CO2e – from the health system’s largest hospital alone.

“In terms relative to our day-to-day lives,” said Ingoldby, “one hour of general anesthesia using desflurane can be compared to driving 400 miles in a car, versus only eight miles of driving when sevoflurane is used at clinically equivalent doses.”

It’s the first known instance of a healthcare organization choosing to eliminate a drug because of its impact on the environment.

Decisions are quick. Change happens slowly.

The data and cost analysis seem clear. If desflurane is the leading culprit for climate change among anesthetic gases in acute-care settings and it’s markedly more expensive to use, why is anyone still using it?

“I can think of two reasons,” said Ingoldby. “The first is, some practitioners choose desflurane near the end of procedures as it allows for quick wakeups.”

Simmonds agrees. “Desflurane leads to quicker induction and recovery from anesthesia compared to sevoflurane, making it the preferred choice for rapid emergence.”

According to the American Journal of Health-System Pharmacy, there is evidence of slightly faster wakeup times with desflurane compared with sevoflurane. Desflurane allows for a reduction in time-to-tracheal-extubation of 1.3 minutes following a surgery of up to three hours.

But according to the same study, there was no significant difference between desflurane and sevoflurane when it came to discharge time from the PACU.

And for longer surgeries, desflurane wakeup times are comparable to sevoflurane and other volatile anesthetics.

Nonetheless, reason no. 1 leads directly to reason no. 2: habit and comfort.

“These two reasons are connected,” said Simmonds. “Because sevoflurane takes more planning to ensure a prompt wakeup, many anesthesiologists and CRNAs prefer desflurane it because it’s seen as easier to use.”

Ingoldby agrees. “It’s simply that, for some, desflurane is what they’re most practiced with using and therefore are the most comfortable with.”

This might be the roadblock to a nationwide switch, even in the face of such compelling data.

The Yale School of Medicine has tracked hospitals across the country as they work to transition practitioners from desflurane to sevoflurane. In a recent interview with NPR, Jodi Sherman, associate professor of anesthesiology at Yale, said results of attempting the switch were mixed.

“Some (hospitals) just gave anesthesiologists the information, and not much changed. Other hospitals took desflurane away, but that left many anesthesiologists feeling disrespected and angry.”

The keys, she says, are data and discussion.

Both Simmonds and Ingoldby say discussion around desflurane’s impact on global warming has been a hot topic among local anesthesiologists and CRNAs for the last few years, which likely helped lead to the department’s recent unanimous vote to discontinue its use.

“My hope is that our action will start a domino effect through the rest of the Peaks hospitals that still have desflurane,” Simmonds said, “and that this is just the first chapter of changes we can make to help to protect our environment.”

Next chapter: nitrous oxide

Good Samaritan offers a piped supply of nitrous oxide to the ORs.

• Less potent than other inhalational anesthetics, it must be used in high concentrations, typically at 50 percent.

• It has a very long atmospheric lifetime at 114 years. (Desflurane is just 14 years)

• Its global-warming impacts are similar to desflurane in clinically relevant doses.

But the issue here isn’t the use of nitrous; it’s the loss of it. A piped system creates considerable waste because of a very high rate of loss from where it’s stored to where it’s moved through the pipes. Before it ever reaches the patient, nitrous oxide leaves a large carbon footprint.

“We should consider switching to tanks of nitrous that are attached to the ventilators and can be turned on when needed and off when not,” said Simmonds. “Likely a cost savings, but more importantly, it would be a significant benefit to the environment.”

That’s just one additional step. More are likely on the clean and crisp horizon.

“Personally, I feel the amount of waste we generate with each surgery is astounding,” said Simmonds. “We need to find ways to address this. There must be a way to provide excellent medical care without so much waste.”

For more information or to offer additional ideas to reduce waste and the carbon footprint at Good Samaritan, please reach out to Ingoldby or Simmonds.