Carbon Footprint of Anesthesia: Comment

We read with great interest the recent article by McGain et al.¹  that quantified the carbon footprint associated with the provision of spinal anesthesia and general anesthesia for total knee arthroplasty. This type of encompassing evaluation is valuable as it is not clouded by biases and highlights that meaningful carbon dioxide equivalent emission comparison depends greatly on local energy generation conditions and individual/institutional anesthesia practice standards. Examining the conduct of spinal anesthesia in the study by McGain et al., there are several components that could be refined to significantly reduce the carbon burden of a neuraxial-based anesthetic.

The largest component of carbon dioxide equivalent emissions associated with spinal anesthesia is related to the electricity required for cleaning and sterilizing reusables (gowns, hand towels, among others). The significant environmental impact associated with the use of sterile gowns for spinal anesthesia mandates a thorough evaluation of this practice.¹  The risk of infectious complications associated with neuraxial anesthesia is incredibly low (0.2 to 0.3:10,000), and the American Society of Anesthesiologists (Schaumburg, Illinois) guidelines have not recommended sterile gown wearing for these procedures.^2,3  Furthermore, the requirement for sterile hand towels is questionable as alcohol-based hand rub has been shown to be an effective means to reduce cutaneous bacterial counts.⁴ 

The second largest contributor of carbon dioxide emissions associated with the provision of spinal anesthesia in this study is high oxygen flow rates. Given that spinal anesthesia results in complete lower extremity anesthesia, moderate to low levels or no sedation usually suffices, and therefore it may be possible to significantly reduce supplemental oxygen requirements.

Third, the development of a significant and collective environmental conscience among patients and medical providers can be harnessed to drive impactful change. As more members of society elect to purchase an electric vehicle, utilize reusable bags, or forgo plastic packaging, they may also be interested in making a similar conscientious and informed decision about the environmental impact of their anesthetic choice and practice. Practitioners are now positioned to evaluate their equipment and demand from their manufacturers equipment that has a diminished impact on the environment. In certain clinical settings (i.e., busy orthopedic or obstetric practices), opportunities may exist to build a subarachnoid anesthesia kit with only the absolutely essential components, which may reduce waste and cost, although the carbon dioxide equivalent impact remains unknown.

McGain et al. should be commended for their description of the environmental impact of their institutional practices, and this study should serve as a rallying cry that compels us to reflect upon our own practices, motivate positive change, and improve the health of our patients beyond the operating room through data-driven adjustments to standard anesthetic delivery.

The authors would like to thank the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine; Pittsburgh, Pennsylvania) for their support of the Green Anesthesia Special Interest Group.

The authors are members of the ASRA Pain Medicine Green Special Interest Group, with Dr. Ip serving as the chair of this group. Dr. Schroeder has received speaking honorarium from AudioDigest and Northwest Anesthesia Seminars.