The intersection of climate change and surgery

Climate change is one of the greatest global public health threats of this century,¹ and it directly affects the field of surgery in multiple ways. As anomalously warmer temperatures occur with increasing frequency as a result of global warming, noted increases in accidental and nonaccidental trauma and deaths have occurred.² Surgical site infections are higher in summer months and will likely rise as warming continues.³ In addition, global warming contributes to the exacerbation of extreme weather events, such as hurricanes and wildfires, which leads to disruptions to surgical care and delivery, and contributes to medication and supply shortages.⁴

Health care accounts for 8 to 10 percent of all greenhouse gas (GHG) emissions in the U.S., with hospitals as the second-most energy intensive commercial buildings in the U.S.^5-7 Increased GHG emissions trap excess heat, leading to global warming and rising sea levels, which contributes to more severe heat waves, increased risk of flooding, and other intensified weather-related events. Through these changes in the environment, climate change affects the health of our patients, heightening the effects of asthma, allergies, heart disease, mental health conditions, poor nutrition, lung cancer, and waterborne and vector-borne illnesses.¹

These climate effects also exacerbate existing racial and economic disparities in health care.⁸ Vulnerable patient populations, including communities of color and areas of lower socioeconomic status, are disproportionately affected by pollution and global warming. Long-standing divestment in these communities, as well as lack of access to funding and infrastructure to mitigate the effects of climate change, have resulted in more severe heat waves, higher levels of pollution, and greater risk of damage during extreme weather. Consequently, historically marginalized populations bear the burden of climate change with an increase in existing health care inequities.

Operating rooms (ORs) account for 20 to 33 percent of hospital waste and can be three to six times more energy-intensive than hospitals as a whole.^9,10 ORs are responsible for a significant portion of GHG emissions, waste production, and energy expenditure. Surgery, as practiced today, is a major propellant of climate change. In medicine, we strive to improve public health, but, ironically, through our wasteful practices we are having the opposite effect. As such, surgeons should not be exempt from reducing our collective carbon footprint and must lead the charge for change.

How climate change affects surgical patients

Fossil fuels still power most of what we use on a daily basis, including our cars and stoves, as well as heating, ventilation, and air conditioning (HVAC) systems in the OR. They also are used to produce plastic, which is the basis for many of the single-use disposable materials used in the OR. Combustion of fossil fuels contributes to air pollution by emitting particles into the air, and it contributes to global warming through the release of GHGs such as carbon dioxide (CO₂). Following are a few ways that climate change and poor air quality affect the health of surgical patients:

• Major storms: Global warming is contributing to the increased severity of natural disasters such as hurricanes and wildfires, which often cause widespread morbidity and mortality.¹ The annual frequency of major storms, which cause more than $1 billion in damages across the U.S., has increased dramatically over the last several decades.¹¹ Most climate change models anticipate a continuation of this trend.¹² Through associated flooding, power outages, and structural damage, such storms can impact surgical systems.^13-15 Elective cases often are canceled and access to emergency trauma care can be limited during an acute disaster.
• Pregnancy outcomes: Prenatal exposure to both air pollution and extreme heat increase the risk of pregnancy complications, ranging from preterm birth to low birthweight.^16,17 Risks are highest among Black mothers. We know these adverse pregnancy outcomes can predispose newborns to early-life surgical pathology, including necrotizing enterocolitis.^18,19
• Heat wave mortality: Mortality rates across the U.S. increase by nearly 4 percent during heat waves, with the greatest effects seen in elderly patients.²⁰ Although little data are available for surgery-specific morbidity and mortality during heat waves, cardiac morbidity is known to increase because of warmer temperatures, which is an important variable to consider when weighing perioperative risk.²¹ In addition, trends toward higher incidence of surgically managed disease during summer months suggests a relationship between surgical disease burden and heat.^22,23
• Allergies: Rising global temperatures have been correlated with longer and more intense pollen seasons across the Northern hemisphere.^24,25 This phenomenon translates into a worsening burden of disease for patients and the need for more aggressive management by otolaryngologists across the U.S.
• Air pollution and surgical outcomes: Although it is challenging to correlate air pollution with surgical intervention, a few initial studies correlate worse surgical outcomes to higher levels of airborne pollution, known as PM2.5. In cardiac transplant patients, a 10 µg/m³ increment increase in annual exposure to PM2.5 correlates with a 26 percent increased risk of death.²⁶ Among a small cohort of adolescents undergoing bariatric surgery, higher exposure to air pollution from local roadways correlated with less weight loss and decreased improvement in cholesterol.²⁷

Surgeons as leaders in sustainability in the OR

There are many opportunities for surgeons to lead on initiatives that decrease GHG emissions, also known as climate-smart surgery. The choices we make in the OR, from type of anesthesia to instrument preferences, significantly affect the environmental impact of a health care facility. As trusted and respected members of health care institutions, surgeons have an opportunity to influence system-wide change that can reduce a facility’s carbon footprint. Following are three main areas to focus on as surgeons who prioritize sustainability:

• Surgical supply chain: Although recycling can reduce overall waste in the OR, it is important to note that the process of recycling requires energy and thus has a marginal effect overall in reducing emissions.²⁸ As such, minimizing the use of unnecessary items and opting for reusable rather than single-use disposable instruments is a more effective intervention in terms of supply management. In some cases, switching to reusable instruments can reduce operative GHG emissions by nearly 50 percent.²⁹ This change can be achieved through tray reformulation and preference card review, which has an added benefit of significant cost savings. One study at the University of California San Francisco showed that the neurosurgical department wasted approximately $2.9 million in unused supplies annually, which was 13.1 percent of the institution’s total surgical supply cost.³⁰
• Waste anesthetic gases: In the U.S., an estimated 51 percent of emissions associated with surgical care is attributable to waste anesthetic gases.¹⁰ Despite being released in small amounts, anesthetic gases, in particular desflurane and nitrous oxide, have significantly higher global warming potentials than CO₂as a result of their ability to trap heat over time.³¹ One hour of desflurane use, for example, is equivalent to driving a car 235–475 miles.³² Nitrous oxide, in addition to being a potent greenhouse gas, contributes to the depletion of the stratospheric ozone layer.³³ Hence, opting for total intravenous anesthetic, regional anesthesia, or peripheral nerve blocks when clinically appropriate can significantly reduce emissions.
• Energy: ORs are energy-intensive relative to other areas of health care facilities, in part because of the required airflow rates that help maintain a sterile surgical environment. As a result, HVAC systems are responsible for 90 to 99 percent of energy demands within the OR.¹⁰ Consequently, installing light-emitting diode, also know as LED, lighting and switching to renewable energy sources can be beneficial, but the most effective way to reduce energy usage in the OR is to implement HVAC setbacks when ORs are not in use. This initiative requires coordination on a hospital-wide level to install occupancy sensors and override switches in case of emergency but can result in savings from both an environmental and cost perspective. Facilities can reduce energy costs by one-third per OR over the course of a year by using occupancy sensors to reduce air turnover.²⁹

Looking ahead: What is the role of surgeons?

Climate change is an enormous and pervasive issue that leaves few parts of the health care field untouched. While data demonstrating the impact of climate change on the health of surgical patients are growing, the profession as a whole has been far too quiet on this issue. As surgeons who strive to provide the best care for our patients, it is imperative that we start acting more boldly moving forward.

It is often difficult to know where to start, but one of the most important initial steps is to educate ourselves on this topic and then educate our surgical colleagues, residents, students, and hospital administrators. In addition to education, research is essential to better understand the full impact of climate change on surgical patients, as well as to determine the most effective and clinically appropriate changes that can be made to move toward climate-smart surgery.

Adopting mitigation and adaptation strategies as outlined is essential to decreasing the carbon footprint of surgical services. As surgeons, we can determine if our own surgical society and place of work have prioritized sustainability as an advocacy issue, and, if not, encourage them to do so.

Several effective organizations, such as Health Care Without Harm and Practice Greenhealth, can help health care providers develop sustainability initiatives at their institutions. Health Care Without Harm also has started a working group called Surgeons for a Sustainable Future, which allows surgeons to explore their roles within the sustainability movement, as well as collaborate on research and education around climate solutions. Established organizations that help physicians learn how to advocate on behalf of the climate crisis include the Medical Society Consortium on Climate and Health.

The climate crisis is a public health threat that directly affects the field of surgery. The authors encourage all surgeons to consider the implications of climate change access to surgical care, health care equity, and the health of surgical patients and to speak up to promote action that moves the health care sector toward carbon neutrality.

References

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