By Christina Hernandez Sherwood

Photos by Margo Reed

Caoimhe Duffy, Julia Tchou, and Matt Carey stand outside of an operating room
Anesthesiologist Caoimhe Duffy, MD, surgeon Julia Tchou, MD, PhD, and perioperative supervisor Matt Carey are among the leaders of sustainability efforts in operating rooms at HUP.

When Caoimhe Duffy, MD, an assistant professor in the Department of Anesthesiology and Critical Care in the Perelman School of Medicine, came to Penn from her home in Ireland in 2020, she was surprised more wasn’t being done to mitigate the negative impacts of anesthetic gases, many of which are greenhouse gases. Most of the anesthetics used in surgery are ultimately exhaled from the patient unchanged. When they reach the Earth’s atmosphere their impacts are hundreds or even several thousand times greater than an equivalent amount of carbon dioxide. Duffy was attuned to the issue; Ireland’s neighbor Scotland was moving toward a 2023 ban of desflurane, an inhaled anesthetic with the highest global warming potential. Seeing an opportunity to make an impact, she decided to start an anesthesia “greening” project with her residents to reduce the harm of this necessary part of their specialty. 

Duffy is a member of CIRCE: Medicine, a faculty group that brings together providers from Penn Medicine and Children’s Hospital of Philadelphia in sustainability efforts. Her team’s anesthesia initiative is an example of the ways groups from across the organization regularly launch local initiatives to make health care greener. 

These department- and team-level initiatives contribute toward Penn Medicine’s overall push toward becoming the most environmentally friendly health care organization in the nation. 

The wake-up call in anesthesia 

A hand holds up a round magnet with an Earth design and text saying “FGF>MV=WASTE” to encourage anesthesiologists to adjust flow settings.
Magnets attached to anesthesia machines at HUP encourage anesthesiologists to modify the flow rates of gases to reduce waste.

The first step in dialing down the volume of greenhouse gases released from Penn Medicine operating rooms was to reduce anesthesia “flow rates” to more precisely control the speed at which gas flows from the anesthesia machine to the patient. Traditionally, anesthesiologists have preferred higher flow rates to ensure patients receive enough medication, Duffy said. But modern anesthesia machines make it possible to use lower flow rates—wasting less gas—to closely match the amount a patient actually needs, while they are carefully monitored.

After validating that lower flows would be safe for patients, Duffy and her team of residents educated their colleagues about the benefits of reducing flow rate, and affixed magnets to anesthesia machines encouraging use of lower flows. From April to June 2023, the Hospital of the University of Pennsylvania saw its greenhouse gas emissions drop by the equivalent of 30 metric tons of carbon dioxide because of the low-flow anesthesia initiative alone, said John (Jack) Berger, MD, chief resident of quality improvement and patient safety in the Department of Anesthesiology and Critical Care.

“There are a lot of different ways we can deliver anesthetic to a patient in a safe and effective way,” he said. “We’re educating people about the impact of their decisions and teaching them new, but equivalent, ways to achieve the same goal.”

With the team’s support, ORs across Penn Medicine are phasing out the use of desflurane, an anesthetic gas that remains in the atmosphere for 14 years and is often the most expensive option. The process included reducing the number of canisters used, ending the contract for the gas and fully ending its use at HUP by the end of 2023. This will most likely result in cost savings in addition to reducing harm to the planet. Penn Medicine Princeton Medical Center has saved an estimated $30,000 per year since it ceased use of desflurane in 2021 in favor of alternative anesthetics. The health system as a whole is expected to phase out desflurane by the end of 2024.

“We can always improve our practice,” Duffy said. “By improving our practice, we can reduce our waste and make a lot of savings for both the environment and the institution. It really is a three-way win.”

How surgical teams go greener 

Another CIRCE: Medicine member who now leads sustainability initiatives in the hospital operating rooms, Julia Tchou, MD, PhD, a professor of Clinical Surgery, began her efforts in the Division of Breast Surgery at the Hospital of the University of Pennsylvania, where she practices. Tchou and her colleagues in the OR have pursued a series of changes that targeted material and energy use that are emblematic of ways to go greener in other areas of health care. 

Julia Tchou, MD, PhD
Breast surgeon Julia Tchou, MD, PhD, has partnered with colleagues in the OR on many ways to improve sustainability, from streamlining instrument sets to waste reduction.

First, Tchou removed some 20 little-used tools from the standard set of about 100 surgical instruments that are prepared for each procedure, snapped a picture and sent it to her colleagues. She asked, would anyone object to these instruments being removed from the kit? “I trimmed off at least 15 instruments just by doing that,” Tchou said.

Removing unused instruments means fewer chemical solvents are used during cleaning, making the process quicker and less costly, Tchou said. (If a surgeon ever needs one of the instruments that was removed from the standard kit, it was available as a standalone tool.) Tchou is working to expand this project to other divisions in 2024.

Red bag waste—that is, any medical waste that is stained or saturated with blood—was another area Tchou targeted. Because red waste bins and municipal waste bins were typically the same size and placed next to each other, trash that should have been tossed into the regular bins made its way into the red bags. But processing red bag waste is expensive and energy intensive, so Tchou borrowed an idea from behavioral economics to pilot a program meant to make it easy for people to change their waste habits. “We could probably implement a really simple change,” she said, “to help change people’s habits and practice.”

In an empty operating room, a large trash can with a clear plastic bag is seen in the foreground and a smaller can with a red bag in the background.
Trash that has been soiled with blood must be deposited in red bags—and disposing of this waste generates more pollution and greenhouse gases than regular trash. Simple behavioral nudges like using smaller cans are reducing unnecessary red bag waste.

Tchou swapped the standard-sized red bag bins for smaller bins in the Perelman Center’s outpatient Surgicentre, while keeping the municipal waste bins the same. The move, she said, was a “game changer.” Tchou said the center’s environmental supervisor told her the change effectively halved the amount of red bag waste produced there. The project is now being implemented at the Pavilion.

Tchou is also working on a “no print” option that would not only save paper—a financial and environmental win—but could also noticeably improve patient care. Traditionally when Tchou prints a request for a patient to consult another provider, it includes a phone number for the patient to call for a follow-up appointment. But many patients fall through the cracks without scheduling follow-up care.

Shifting to electronic consultation requests would remove that step from the equation, Tchou said, instead forwarding the information to the other provider’s office so the patient receives a call to schedule their appointment when they need it—making care easier for the patient, while reducing waste at the same time. 

“The goal is to take equally good or better care of the patient in front of you,” said Misha Rosenbach, MD, a professor of Dermatology and co-leader of CIRCE: Medicine, “without negatively hurting population health with the downstream byproducts of the practice of medicine.”

Explore more coverage of sustainability at Penn Medicine 

How Penn Medicine is going green for good health: To improve health while addressing climate change, Penn Medicine is investing in major initiatives to become the most environmentally friendly health care system in the country.

Health care teams “act locally” to support Penn Medicine sustainability goals: Teams across Penn Medicine are working hard to “think globally, act locally” when making environmentally friendly changes in their day-to-day operations.

Health research on a warming planet: Climate change affects human health, from viral transmission to the effectiveness of medications. Researchers at Penn Medicine are discovering how and seeking solutions.

How the next generation of physicians will combat climate change: Through a new Planetary Health curriculum, Penn medical students are learning about the impact of climate change on human health.

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